Extrusion drilling tools, extrusion pile machine and extrusion pile construction method

Abstract

The invention discloses an extrusion and expansion drilling tool, an extrusion and expansion pile machine and an extrusion and expansion pile forming method, comprising a drill bit, an extrusion and expansion body, a connecting rod and a pin shaft, wherein the extrusion and expansion body is composed of a cylindrical retaining body and a special-shaped threaded extrusion and expansion body, the special-shaped threaded extrusion and expansion body comprises a core tube, blades and an Archimedean spiral surface, the upper end of the core tube is fixedly connected to the lower end of the connecting rod via an extrusion and expansion upper joint and a pin shaft, and the lower end is fixedly connected to the drill bit, the upper part of the core tube is serially connected with a cylindrical retaining body, and the lower part is spirally wound with equal-pitch blades along the axis upward; an extrusion and expansion pile machine comprises the extrusion and expansion drilling tool and a pile forming method, wherein the extrusion and expansion pile machine uses a gradually enlarged Archimedean spiral surface to extrude and expand in situ during synchronous drilling, so that the soil is not sheared and is not transported upward, and the invention has the advantages of high construction efficiency, low power consumption, good soil extrusion effect, higher pile forming quality, no drill jamming, no drill burial, long service life and the like.

Description

Technical Field

[0001] The invention relates to foundation construction equipment, in particular to an extrusion-expansion drilling tool, an extrusion-expansion pile driver and an extrusion-expansion pile construction method. Background Art

[0002] In the field of foundation engineering, spiral drilling machines play a huge role in modern pile foundation construction. In particular, PLC-controlled variable frequency pile drivers can complete bored piles, threaded piles, screw piles, continuous walls, squeezed piles, soft foundation treatment and other foundation construction according to different requirements of foundation construction. Existing squeezed pile construction methods and drilling tool patent technologies are emerging in an endless stream. There are many applications, and the more typical ones are:

[0003] 1> Patent number is CN200710063983.3 Bidirectional spiral extrusion pile construction method and bidirectional spiral closed extrusion drill bit,

[0004] 2> Patent number is CN201714304U-extendable bidirectional spiral extrusion drill bit,

[0005] 3> Patent number is CN201020133115.5-bidirectional spiral extrusion drill bit with soil guide groove,

[0006] 4> Patent number is CN200710051598.7 Rotary extrusion cast-in-place pile and its pile construction method,

[0007] The above four patents respectively describe the bidirectional spiral extrusion pile construction method and bidirectional spiral closed extrusion drill bit; extendable bidirectional spiral extrusion drill bit; bidirectional spiral extrusion drill bit with soil guide groove; rotary extrusion cast-in-place pile and its pile construction method.

[0008] There are the following defects and problems in the above patents, which are now described separately:

[0009] 1. CN200710063983.3 Bidirectional spiral extrusion pile construction method and bidirectional spiral closed extrusion drill bit,

[0010] Its construction method:

[0011] Start the pile drilling rig to apply clockwise torque and downward axial pressure, and use the bidirectional spiral closed extrusion drill bit to drill and expand the hole. During the downward rotary drilling and extrusion process, the soil drilled out will make a spiral motion from bottom to top and gradually be squeezed into the side wall of the pile hole, so that the diameter of the pile hole after extrusion meets the design requirements. The first step of the pile hole mechanical extrusion process will continue until the pile hole reaches the designed depth;

[0012] The shortcomings of its method:

[0013] The soil that is drilled out by the rotary drill makes a spiral motion from bottom to top and is gradually squeezed into the side wall of the pile hole. The whole drilling tool will generate great resistance: Resistance 1: The soil that is drilled out by the rotary drill, that is, the soil that is bonded together is cut off, forming a shear resistance from bottom to top. Resistance 2: The soil moves from bottom to top and generates friction resistance with the drill rod, the soil stirs each other and forms friction resistance, and the soil is lifted and generates gravity resistance. Resistance 3: The extrusion resistance of the soil being gradually squeezed into the side wall of the pile hole. Since the soil is rotated out by the spiral conveying principle and sent into the extrusion and expansion body by the spiral propulsion movement, and the upper extrusion and expansion body of the bidirectional spiral closed extrusion and expansion drill is blocked and squeezed, the lower soil moves upward to form a local dense soil body, resulting in increased resistance. When the resistance is equal to the spiral lift of the soil, a balanced state is reached, the extrusion effect tends to zero, and it cannot be squeezed. In addition, the superposition of many resistances consumes a lot of energy, which is an inherent defect of its use of the spiral motion principle.

[0014] Its extrusion and expansion drill bit:

[0015] The bidirectional spiral closed extrusion and expansion drill bit used in the bidirectional spiral extrusion and expansion pile construction method comprises a hollow connecting rod, a connecting flange is provided at the top end of the connecting rod, and a drill tip is provided at the bottom end. The lower part of the connecting rod is coaxially fitted with or integrally formed with a lower spiral extrusion and expansion body, a closed extrusion and expansion body and a dynamic sealing extrusion and expansion body from bottom to top. The dynamic sealing extrusion and expansion body is a frustum with a cross section gradually decreasing from bottom to top, and the outer side wall of the dynamic sealing extrusion and expansion body is provided with left-handed dynamic sealing spiral extrusion and expansion blades. The closed extrusion and expansion body is a cylinder, and the lower spiral extrusion and expansion body is a frustum with a cross section gradually increasing from bottom to top, and the outer side wall of the lower spiral extrusion and expansion body is provided with right-handed lower spiral extrusion and expansion blades.

[0016] The expansion drill bit is insufficient:

[0017] The lower spiral expansion body, the closed expansion body and the dynamic sealing expansion body are integrally formed, and the structure is huge, inconvenient to replace and maintain, and the replacement cost is high. The dynamic sealing expansion body is a truncated cone with a cross section gradually decreasing from bottom to top, and the spiral expansion body is a truncated cone with a cross section gradually increasing from bottom to top. The upper cone generates an upward thrust on the descending soil, and the lower cone generates a downward thrust on the ascending soil. The soil is sheared off and pushed upward under the action of the spiral blades (or threads), while the spiral expansion body is a truncated cone with a large upper part and a small lower part, which generates a thrust toward the hole wall and downward on the ascending soil. The downward thrust hinders the descent of the drill bit, and the drill bit must rely on its own gravity and the pressure of the pile driver to descend. Since the squeezing and expanding body adopts a truncated cone structure, the cross section of the squeezing and expanding body is circular in the cross section perpendicular to the axis of the drill. When the drill makes a rotary motion, the squeezing and expanding body of the truncated cone structure has no squeezing and expanding effect. Only when the drill moves downward, the inclined surface of the squeezing and expanding body of the truncated cone structure generates squeezing and expanding force toward the side and bottom of the hole to achieve the squeezing and expanding effect. The squeezing and expanding force toward the bottom of the hole makes the soil under the squeezing and expanding body more compact, making the drilling resistance greater and greater. Therefore, this structure has large resistance, large power consumption, and low squeezing efficiency. This is an inherent defect of its truncated cone structure.

[0018] 2. CN201714304U-Extensible bidirectional spiral extrusion drill bit,

[0019] The substantial deficiencies of its drill bit structure:

[0020] This patent is based on the patent "CN200710063983.3 Bidirectional spiral extrusion pile construction method and bidirectional spiral closed extrusion drill bit", which is divided into sections and then connected. The lower part of the extrusion body can be extended arbitrarily, and the resistance is reduced by reducing the extrusion amount to increase the drilling depth. The extrusion body structure has no substantial changes, and it has the above-mentioned shortcomings of the patent "CN200710063983.3 Bidirectional spiral extrusion pile construction method and bidirectional spiral closed extrusion drill bit (1)". At the same time, the soil of the lengthened spiral drilling body is not extruded by the extrusion body, and the extrusion effect is reduced.

[0021] 3. CN201020133115.5 Bidirectional spiral extrusion drill bit with soil guide groove,

[0022] Its shortcomings:

[0023] Although the patent also describes the problems in the actual use of the bidirectional spiral enclosed extrusion drill bit (CN200710063983.3), "Since the bidirectional spiral enclosed extrusion drill bit is used to expand the soil in the original pile hole into the side wall of the pile hole in both directions during drilling and lifting, it is found in actual drilling construction that the friction resistance from the side wall of the pile hole to the drill bit is very large, which not only increases power consumption but also reduces drilling efficiency." However, the solution adopted by the patent is to release the friction resistance from the side wall of the pile hole to the drill bit through the soil guide groove, "so that the drilling power consumption is reduced and the drilling efficiency is high", but there are substantial technical problems such as reduced soil extrusion effect, extrusion and release during drilling, consumption of a lot of power, and useless work. And the structural defects of the drill bit are the same as those in the two patents "CN200710063983.3 Bidirectional spiral extrusion and expansion pile construction method and bidirectional spiral closed extrusion and expansion drill bit" and "CN201714304U-Extensible bidirectional spiral extrusion and expansion drill bit".

[0024] 4. CN200710051598.7 Rotary extrusion cast-in-place pile and its pile construction method

[0025] The substantial deficiencies of this structure and pile construction method are:

[0026] The soil is squeezed within the pile length range to form a straight rod nut-shaped soil, and then the drill rod rotates forward in situ asynchronously. At this time, no squeezing force is formed, but shearing of the nut soil is formed. The threads of the nut-shaped soil are sheared to form a cylindrical pile hole. Because the nut-shaped soil of the entire threaded pile hole needs to be rotated and sheared, the power head motor power requirement is very large, consuming a lot of power, and the motor is difficult to start, which is easy to burn the motor, jam the drill and bury the drill. The nut-shaped soil between the threads of the drill tool is not squeezed into the side wall, but is sheared off and left in the thread spacing of the drill rod. Not only is the soil squeezing effect poor, but the soil left in the thread spacing of the drill rod will also be brought out of the ground. This is an inherent defect of its drill tool structure and construction method.

[0027] It can be seen from this that the above four patents respectively adopt the principle of spiral propulsion extrusion and soil squeezing, synchronous self-tapping thread rotation soil squeezing, and asynchronous rotation shearing principle. Due to the inherent defects of their structures and methods, they all have problems such as large drilling rig power consumption, low construction efficiency, poor soil squeezing effect, poor pile quality, easy drill sticking, and buried drill. Summary of the invention

[0028] The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art and to provide an extrusion and expansion drill, an extrusion and expansion pile driver and an extrusion and expansion pile forming method which have a reasonable structure and method, high construction efficiency, low power consumption, good soil extrusion effect, higher pile quality, are not prone to drill sticking or drill burial, and have a long service life.

[0029] The technical solution adopted by the present invention to solve its technical problem is:

[0030] A drilling tool for extrusion and expansion, comprising a drill bit (1), an extrusion and expansion body (2), a connecting rod (3), and a pin (4), characterized in that the extrusion and expansion body (2) is composed of a cylindrical retaining body (2-1) and a special-shaped threaded extrusion and expansion body (2-2), the special-shaped threaded extrusion and expansion body (2-2) comprising a core tube (2-2-1), blades (2-2-2) and an Archimedean spiral surface (2-2-3), the upper end of the core tube (2-2-1) is fixedly connected to the lower end of the connecting rod (3) via an extrusion and expansion upper joint (2-2-4) and a pin (4), and the lower end is fixedly connected to the drill bit (1), the upper part of the core tube (2-2-1) is serially connected to the cylindrical retaining body (2-1), and the lower part is spirally wound upward along the axis with the same The invention relates to a pitch blade (2-2-2), wherein the lower end of the cylindrical retaining body (2-1) is fixedly connected to the blade (2-2-2), the outer diameter of the cylindrical retaining body (2-1) is the same as the diameter of the blade (2-2-2), the Archimedean spiral surface (2-2-3) uses the radius of the core tube (2-2-1) as the minimum starting polar diameter, uses the distance between the connection points of two adjacent blades (2-2-2) and the core tube (2-2-1) as the starting width, and starts from between the two blades at the lower end of the core tube (2-2-1), along the spiral trajectory of the blade (2-2-2) and is wound between the two blades in the manner of an Archimedean spiral line, forming a curved surface called the Archimedean spiral surface (2-2-3). The Archimedean spiral surface (2-2-3) -3) is parallel to the axis of the core tube (2-2-1), and the upper end of the Archimedean spiral surface (2-2-3) is always fixedly connected to the lower end surface of the upper blade (2-2-2) of the adjacent blade during the winding process, and the lower end is always fixedly connected to the upper end surface of the lower blade (2-2-2) of the adjacent blade. The polar diameter of the Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a cylindrical retaining body (2-1), so that the Archimedean spiral surface (2-2-3) has a cam effect during synchronous drilling and rotary soil squeezing, and at the same time, the cylindrical retaining body has the function of maintaining the aperture and stabilizing the axis of the drilling tool. The diameter of the connecting rod is not greater than the diameter of the cylindrical retaining body, so that the extrusion and expansion drill tool reduces resistance during the rotational drilling process, so that the soil thread after the drill bit (1) drills the hole is gradually increased by the polar diameter of the Archimedean spiral surface (2-2-3) on the extrusion and expansion body (2) that rotates downward, which is equivalent to the cam polar diameter from small to large, so that the soil is squeezed into the side wall of the pile hole in situ, which significantly improves the quality of pile formation. Finally, when the cylindrical retaining body (2-1) on the extrusion and expansion drill tool reaches the original position of the soil, the pile hole diameter is further maintained to meet the construction requirements. Since the diameter of the connecting rod is not greater than the cylindrical retaining body, the extrusion and expansion drill tool further reduces resistance during the rotational drilling process, and thus gradually drills down to the designed depth of the pile hole.

[0031] According to the present invention, an upper joint plug (1-1) can be provided at the upper end of the drill bit (1), and a lower joint (2-2-5) can be provided at the lower end of the core tube (2-2-1) of the special-shaped threaded extrusion and expansion body (2-2). The upper joint plug (1-1) is fixedly connected to the lower joint (2-2-5) of the core tube (2-2-1) via a distribution shaft (4), so as to achieve the effects of expanding construction capacity and facilitating maintenance.

[0032] The present invention may also provide a drill core tube (1-2) between the drill bit (1) and the upper joint plug (1-1), the drill core tube (1-2) being threaded with drill blades (1-3), the drill blades (1-3) and the blades (2-2-2) on the extrusion and expansion body (2) having the same outer diameter, thickness and lead, and the connection parts are butt-jointed to form a continuous equal-pitch blade (2-2-2), so as to achieve synchronous drilling and extrusion and reduce soil extrusion resistance, increase the drill length, meet the requirements of screw piles, and can be used for extrusion and expansion of screw pile holes.

[0033] The outer wall of the cylindrical expansion body and the blade of the expansion body of the present invention is provided with a ventilation groove (15), and the ventilation groove (15) is axially arranged. At least two ventilation grooves (15) are arranged in an array along the outer circumference of the expansion body to facilitate the discharge of compressed gas sent into the bottom during the drilling process.

[0034] The connecting rod (3) of the present invention may be a bare rod, a long spiral drill rod, or a threaded drill rod, so as to be adaptable to different pile drivers.

[0035] When part of the soil layer in the pile hole is very soft and the bottom of the pile hole is required to be a threaded hole, the present invention can also coaxially connect a same-direction extrusion expansion body (22) between the extrusion expansion body (2) and the connecting rod (3), the same-direction extrusion expansion body (22) mainly comprising a same-direction core tube (22-2-1), same-direction blades (22-2-2), same-direction Archimedean spiral surfaces (22-2-3) and a same-direction cylindrical retaining body (22-1), the upper end of the same-direction core tube (22-2-1) is fixedly connected to the connecting rod (3) via a second upper joint and a second upper pin shaft, and the lower end is fixedly connected to the upper joint of the upper end of the extrusion expansion body (2) via a second lower joint and a second lower pin shaft, and the same-direction blades (22-2-2) are axially spirally wound on the same-direction core tube (22-2-1). A unidirectional cylindrical retaining body (22-1) is serially connected to the lower part of the unidirectional core tube (22-2-1); the outer diameter of the unidirectional cylindrical retaining body (22-1) is the same as the outer diameter of the cylindrical retaining body (2-1); the unidirectional Archimedean spiral surface (22-2-3) uses the radius of the unidirectional core tube (22-2-1) as the minimum starting pole diameter and the spacing between the connecting points of two adjacent unidirectional blades (22-2-2) and the generatrix of the unidirectional core tube (22-2-1) as the starting width; and the curved surface formed between the two unidirectional blades of the first group at the upper end of the unidirectional core tube (22-2-1) and wound along the spiral trajectory of the unidirectional blades (22-2-2) in the form of an Archimedean spiral line is called the unidirectional Archimedean spiral surface (22-2-3). The axial generatrix on the Archimedean spiral surface (22-2-3) is parallel to the axis of the same-direction core tube (22-2-1), and the upper end of the same-direction Archimedean spiral surface (22-2-3) is always fixedly connected to the lower end surface of the upper blade (22-2-2) of the adjacent same-direction blade during the winding process, and the lower end is always fixedly connected to the upper end surface of the lower blade (22-2-2) of the adjacent blade. The polar diameter of the same-direction Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a same-direction cylindrical retaining body (22-1), so that the same-direction Archimedean spiral surface (22-2-3) has a cam effect when rotating in the opposite direction to squeeze soil, so that the extrusion and expansion drilling tool can be adjusted after reaching the set depth. , the rotation and drilling are stopped synchronously, and the control device instructs the winch mechanism and the power head to rotate in the opposite direction synchronously and lift to withdraw the thread. At this time, a threaded hole is formed at the bottom of the pile hole due to the synchronous withdrawal of the spiral blades of the extrusion and expansion drill. During the process of withdrawing the thread, when the loose soil part of the pile hole side wall that has been squeezed and expanded at the upper part of the same-direction extrusion and expansion body (22) falls off, under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surface (22-2-3) on the same-direction extrusion and expansion body (22), the same-direction Archimedean spiral surface (22-2-3) has a cam effect when rotating in the opposite direction to squeeze the soil, and the fallen soil is radially squeezed into the pile hole side wall again, and the pile hole is shaped and maintained by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1).Until the extrusion and expansion drill moves upward and is lifted to the ground surface to form a screw pile hole. This not only reduces the resistance of the soil to the drill, but also prevents the soil falling from the side wall of the pile hole from falling out of the ground, significantly improving the quality of the pile hole.

[0036] When the bottom of the pile hole is required to be a smooth hole, the present invention can also be provided with a reverse upper extrusion expansion body (23) coaxially connected between the extrusion expansion body (2) and the connecting rod (3), the reverse upper extrusion expansion body (23) mainly comprising a reverse core tube (23-2-1), reverse blades (23-2-2), a reverse Archimedean spiral surface (23-2-3) and a reverse cylindrical retaining body (23-1), the upper end of the reverse core tube (23-2-1) is fixedly connected to the connecting rod (3) via a third upper joint and a third upper pin shaft, and the lower end is fixedly connected to the upper joint of the upper end of the extrusion expansion body (2) via a third lower joint and a third lower pin shaft, the upper axial spiral of the reverse core tube (23-2-1) is provided with a reverse blade (23-2-2), and the lower portion of the reverse core tube (23-2-1) is connected to a reverse spiral surface. A reverse cylindrical retaining body (23-1) is connected, the outer diameter of the reverse cylindrical retaining body (23-1) is the same as the outer diameter of the cylindrical retaining body (2-1), the reverse Archimedean spiral surface (23-2-3) uses the radius of the reverse core tube (23-2-1) as the minimum starting polar diameter, and uses the distance between the connection points of two adjacent reverse blades (23-2-2) and the generatrix of the reverse core tube (23-2-1) as the starting width. The curved surface formed by winding between the two blades in the manner of an Archimedean spiral line starting from the first group of two reverse blades at the upper end of the reverse core tube (23-2-1) and along the spiral trajectory of the reverse blade (23-2-2) is called the reverse Archimedean spiral surface (23-2-3), and the axial generatrix on the reverse Archimedean spiral surface (23-2-3) is the same as the reverse Archimedean spiral surface (23-2-3). The reverse Archimedean spiral surface (23-2-3) is parallel to the axis of the core tube (23-2-1), and the upper end of the reverse Archimedean spiral surface (23-2-3) is always fixedly connected to the lower end surface of the upper blade (23-2-2) of the adjacent reverse blade during the winding process, and the lower end is always fixedly connected to the upper end surface of the lower blade (23-2-2) of the adjacent reverse blade. The polar diameter of the reverse Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a reverse cylindrical retaining body (23-1), so that the reverse Archimedean spiral surface (23-2-3) has a cam effect when rotating and squeezing soil in the positive direction, so that after the squeezing and expanding drill tool reaches the set depth, the control device instructs to stop drilling, and the power head continues to work with the drill. The extrusion and expansion drill bit (23) rotates in the same direction as the drilling tool. At this time, the soil thread at the bottom of the pile hole is sheared off in situ to form a smooth hole. After the extrusion and expansion drill bit rotates for at least one circle, the drill bit is lifted upward, and the power head continues to rotate in the same direction as the drilling tool. During the upward lifting process, when the loose soil on the pile hole side wall that has been squeezed and expanded at the upper part of the reverse extrusion and expansion body (23) falls, the reverse blades (23-2-2) and the reverse Archimedean spiral surface (23-2-3) on the reverse extrusion and expansion body (23) radially squeeze the fallen soil into the pile hole side wall again, and the pile hole is shaped and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill bit moves upward to the ground surface to form an extrusion and expansion pile smooth hole, which not only improves the extrusion and expansion rate, but also reduces the resistance of the soil to the drill bit.It also significantly improves the pile hole quality.

[0037] The present invention can provide a second ventilation groove (16) on the outer wall of the same-direction cylindrical extrusion body and the same-direction blade of the same-direction extrusion body, and the second ventilation groove (16) is axially arranged, and the second ventilation groove (16) is connected with the first ventilation groove to form the same air outlet groove, so that the gas is discharged along the first ventilation groove (15) and the second ventilation groove (16).

[0038] The present invention can provide ventilation groove three (17) on the outer wall of the reverse cylindrical extrusion body and the reverse blade of the reverse extrusion body, and the ventilation groove three (17) is axially arranged, and the ventilation groove three (17) is connected with the ventilation groove one (15) to form the same air outlet groove, so that the gas can be discharged along the ventilation groove one (15) and the ventilation groove three (17).

[0039] When the threaded hole needs to be lengthened, the drill bit (1) can be replaced, or a threaded drill rod section (31) with the same pitch to form an integral thread can be added between the lower joint of the core tube (2-2-1) of the extrusion and expansion drilling tool and the drill bit (1). The core tube of the threaded drill rod section (31) has the same shape and diameter as the core tube of the drill bit on the drill bit. The spiral blades on the threaded drill rod section (31) have the same outer diameter, thickness and lead as the drill blades (1-3) on the drill bit. After connection, the blades on the threaded drill rod section (31) are butted with the special-shaped threaded extrusion and expansion body and the drill bit to form a continuous equal-pitch blade (2-2-2). The ventilation groove three provided on the outer wall of the blade of the threaded drill rod section (31) is butted with the ventilation groove one and the ventilation groove two to form the same air outlet groove, so as to reduce the resistance to extrusion and increase the length of the bottom threaded hole, or to meet the requirements of the screw pile and form an extrusion and expansion screw pile hole.

[0040] The invention utilizes the gradually enlarged Archimedean spiral surface (2-2-3) to squeeze and expand in situ during the synchronous drilling process, so that the soil is not sheared, not transported upward, and does not use the truncated cone body to squeeze and generate upward resistance. The radial situ squeezing greatly reduces the resistance applied to the drill tool during the drilling process. The invention solves the substantial technical problems that the truncated cone structure has a circular cross section on the cross section perpendicular to the axis of the drill tool, the truncated cone structure squeezing and expanding body has no squeezing and expanding effect when the drill tool performs a rotary motion, and the truncated cone body inclined surface generates a component force to squeeze the soil downward, resulting in the compaction of the lower soil body, resulting in large resistance, making it difficult for the drill tool to drill, and resulting in low squeezing and expanding efficiency. At the same time, the invention also solves the substantial problem that the spiral blade rotates the soil out and then uses the spiral blade to perform a spiral propulsion motion in the reverse direction to send the soil into the squeezing and expanding body, which consumes a lot of power. The invention also solves the substantial problem that the soil is squeezed within the pile length range to form a straight rod nut-shaped soil body, and then the drill rod is asynchronously rotated forward in situ to squeeze the nut soil body, which consumes a lot of power.

[0041] A pile extrusion and expansion machine comprises a pile frame (5) and a power head (6); the pile frame (5) is provided with a column (7), a diagonal brace (11), a platform (12), a chassis (13), a counterweight (19), a pulley block (14), a traveling mechanism (15), a hoisting mechanism (8), a slewing mechanism (9), a hydraulic system, an operating table and a control device; the connection relationship between the column (7), the diagonal brace (11), the platform (12), the chassis (13), the counterweight (19), the pulley block (14), the traveling mechanism (15), the power head (6), the hoisting mechanism (8), the slewing mechanism (9), the hydraulic system, the power supply, the operating table and the control device is the prior art and will not be described in detail herein; the pile frame is characterized in that it also comprises any one of the extrusion and expansion drilling tools described above.

[0042] A method for forming piles by squeezing and expanding piles, characterized in that the method comprises the following steps:

[0043] 1) The pile extrusion machine is in place.

[0044] An extrusion and expansion drilling tool consisting of a connecting rod (3), an extrusion and expansion body (2), a drill bit (1) and a pin shaft (4) is fixed to the lower joint of the power head of the extrusion and expansion pile driver;

[0045] 2) Synchronous drilling: the front end of the soil is drilled into a soil thread hole, and the rear end of the soil thread is squeezed and expanded into a smooth hole in situ.

[0046] After the extrusion and expansion pile driver is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward by one lead for synchronous drilling. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills a threaded hole in the soil, and during the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped threaded extrusion and expansion body (2-2) of the extrusion and expansion drill tool, which is rotated downward in situ, gradually squeezes the thread formed on the soil into the side wall of the pile hole. , and the formed pile hole is continued to be maintained in compliance with the construction requirements by the cylindrical retaining body (2-1) on the special-shaped threaded extrusion and expansion body (2-2); during the synchronous drilling process, the polar diameter of the Archimedean spiral surface (2-2-3) on the extrusion and expansion body (2) gradually increases, which is equivalent to the polar diameter of the cam increasing from small to large to squeeze the soil into the side wall of the pile hole in situ, so that the resistance of the power head (6) is only the friction between the extrusion and expansion body and the soil on the pile hole wall and the resistance of squeezing the soil toward the hole wall, and no resistance of shearing the soil and transporting the soil is generated, thereby reducing the construction resistance and greatly improving the construction efficiency. At the same time, the effect of not sticking the drill and not burying the drill is achieved, which significantly improves the construction efficiency and the quality of pile formation;

[0047] Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached;

[0048] 3) The soil threads at the bottom are sheared and the drill is lifted.

[0049] After the drill is lifted, a light hole of the squeezed and expanded pile is formed.

[0050] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the hoisting mechanism (8) to stop lowering the extrusion and expansion drill bit. At the same time, the power head (6) continues to rotate and applies torque in the same direction as when the extrusion and expansion drill bit is drilled down, so that the extrusion and expansion drill bit rotates in situ, and the bottom soil thread that the cylindrical retaining body (2-1) has not reached is sheared. After the extrusion and expansion drill bit rotates for at least one circle, the control device controls the hoisting mechanism (8) to lift the power head (6) so that the extrusion and expansion drill bit moves upward until it reaches the ground surface;

[0051] During construction, this method does not form an integral threaded hole. Instead, the soil threaded hole is formed by drilling in situ in the soil while expanding the soil thread into a smooth hole. After drilling to the designed depth, only the soil portion that is not reached by the cylindrical retaining body (2-1) is not expanded. At this time, it is sheared, which greatly reduces the shear torque and improves the construction efficiency. Compared with the existing technology, the implementation of this method will greatly reduce energy consumption and carbon emissions. It is a green, energy-saving, environmentally friendly and efficient construction method.

[0052] 4) into piles

[0053] When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a concrete pile;

[0054] Alternatively, after the extrusion and expansion drill tool moves upward and is lifted to the ground surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile; Alternatively, after the extrusion and expansion drill tool moves upward and is lifted to the ground surface, fillers are poured into the hole and the pile is expanded by tamping. Since the soil is fully squeezed and expanded, the density of the pile hole is high, which greatly improves the bearing capacity of the pile.

[0055] In the present invention, when the bottom of the pile hole is a bare hole during step 3), a reverse upper extrusion and expansion body (23) can be coaxially connected between the extrusion and expansion body (2) and the connecting rod (3). During the upward lifting process, the extrusion and expansion drill tool maintains the rotation direction when drilling down and continues to rotate. When the loose soil on the pile hole side wall falls off after being extruded and expanded, the reverse blades (23-2-2) and the reverse Archimedean spiral surface (23-2-3) on the reverse upper extrusion and expansion body (23) radially squeeze the fallen soil into the pile hole side wall again. The pile hole is shaped and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill moves upward to the ground surface to form an extrusion and expansion pile hole. Since the reverse upward extrusion and expansion body (23) adopts a cam structure with an Archimedean spiral surface, it radially squeezes the soil without generating an upward thrust on the soil body, and does not rely on conveying the soil body downward to be squeezed by a truncated cone, so that space is squeezed out for the soil body that falls downward, so that the fallen soil body is gradually squeezed and expanded by the upward reverse upward extrusion and expansion body (23), achieving a good squeezing and expansion effect. The resistance of the soil body to the drill tool is reduced, and the soil body that falls off the side wall of the pile hole is prevented from falling and being carried out of the ground, which significantly improves the squeezing and expansion efficiency and the pile quality.

[0056] A method for forming piles by squeezing and expanding piles, characterized in that the method comprises the following steps:

[0057] 1) The pile extrusion machine is in place.

[0058] An extrusion and expansion drilling tool consisting of a connecting rod (3), an extrusion and expansion body (2), a drill bit (1) and a pin shaft (4) is sequentially connected to the lower joint of the power head of the extrusion and expansion pile driver;

[0059] 2) The front end of the soil is drilled synchronously to form a threaded hole in the soil, and the rear end of the soil thread is squeezed and expanded in situ to form a smooth hole.

[0060] After the pile extrusion and expansion machine is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward by one lead for synchronous drilling. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills the soil into a threaded hole. During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped thread extrusion and expansion body (2-2) of the extrusion and expansion drill tool, which is rotated downward in situ, gradually squeezes the thread formed on the soil into the side wall of the pile hole, and the cylindrical retaining body (2-1) on the special-shaped thread extrusion and expansion body (2-2) continues to maintain the formed pile hole in compliance with the construction requirements.

[0061] Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached;

[0062] 3) Synchronously withdraw the soil thread at the bottom and then lift the drill.

[0063] After the drill is lifted, a threaded hole is formed at the bottom and a pile hole is squeezed and expanded at the top.

[0064] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the power head (6) and the hoisting mechanism (8) to synchronously stop drilling downwards. At the same time, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) in the reverse direction, so that each time the power head (6) rotates in the reverse direction, the hoisting mechanism (8) lifts the power head (6) and the extrusion and expansion drill tool up by one pitch, and after continuous operation, the extrusion and expansion drill tool synchronously exits the threaded section at the bottom, and is lifted to the ground surface; a threaded extrusion and expansion pile hole is formed at the bottom of the pile hole, and an extrusion and expansion pile hole is formed at the top; the threaded section at the bottom of the pile hole can increase the side touch resistance of the pile, effectively increasing the bearing capacity of the pile, and lengthening the drill bit or adding a screw section can complete the construction of the screw pile.

[0065] 4) into piles,

[0066] When the extrusion and expansion drill tool begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a friction pile. Since the bottom of the pile hole is a threaded hole, the threaded extrusion and expansion pile at the bottom of the concrete pile forms a holding force on the soil, which greatly increases the stability of the pile and improves the bearing capacity.

[0067] Alternatively, after the extrusion and expansion drill moves upward and is lifted to the surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile;

[0068] Alternatively, when the extrusion and expansion drilling tool moves upward and is lifted to the surface, filler is poured into the hole and rammed to form a pile.

[0069] When screw pile construction is required, the present invention can replace the drill bit (1), or add equidistant threaded drill rod sections (31) between the lower joint of the core tube (2-2-1) of the extrusion and expansion drill and the drill bit (1) to increase the bottom thread length to meet the screw pile requirements, so that screw pile construction can be carried out to form screw extrusion and expansion piles.

[0070] When the present invention performs step 3) of returning the pile when the bottom of the pile hole is a threaded hole, the threaded section is gradually withdrawn during the reverse synchronous lifting process, and the extrusion and expansion drill tool maintains the rotation direction of the withdrawn threaded section and continues to rotate. When the loose soil part of the pile hole side wall on the upper part of the same-direction extrusion and expansion body (22) after being squeezed and expanded falls off, the fallen soil is radially squeezed into the pile hole side wall again under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surface (22-2-3) on the same-direction extrusion and expansion body (22), and the pile hole is shaped and retained by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill tool moves upward and is lifted to the ground surface to form a screw pile hole, thereby achieving a good extrusion and expansion effect, reducing the resistance of the soil to the drill tool, and preventing the soil falling off the pile hole side wall from falling off and being carried out of the ground, thereby significantly improving the pile hole quality.

[0071] Due to the adoption of the above structure and construction method, the present invention achieves synchronous drilling and squeezing during the drilling process, and there is no need to squeeze the soil within the pile length range to form a straight rod nut-shaped soil body, which greatly reduces the resistance, significantly improves the construction effect, and achieves high pile quality; there is no need to rotate the soil out, and the soil does not need to perform spiral motion from bottom to top; the soil is gradually squeezed into the side wall of the pile hole in situ by the Archimedean spiral surface under the synchronous action of drilling and rotation, and has the advantages of high construction efficiency, low power consumption, good soil squeezing effect, higher pile quality, no drill jamming, buried drill, long service life, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic structural diagram of an embodiment of the extrusion-expansion drilling tool of the present invention.

[0073] Figure 2 yes Figure 1 Schematic diagram of the decomposition.

[0074] Figure 3 It is a structural schematic diagram of a second embodiment of the extrusion-expansion drilling tool of the present invention.

[0075] Figure 4 yes Figure 3 Exploded diagram of .

[0076] Figure 5 It is a structural schematic diagram of a third embodiment of the extrusion-expansion drilling tool of the present invention.

[0077] Figure 6 yes Figure 5 Exploded diagram of .

[0078] Figure 7 Schematic diagram of screw pile drilling tool structure

[0079] Figure 8 It is a structural schematic diagram of the pile extrusion and expansion machine of the present invention.

[0080] FIG. 9 is a diagram showing the pile driver of the present invention in position.

[0081] FIG. 10 is a diagram showing the synchronous drilling of the extrusion and expansion method of the present invention.

[0082] FIG. 11 is a diagram of the present invention in which the front end of the soil is drilled into a soil threaded hole, and the rear end soil thread is in-situ extruded and expanded into a light hole.

[0083] FIG. 12 is a diagram of the present invention showing the soil thread at the bottom of the extrusion and expansion method being sheared and then the drill being lifted.

[0084] FIG. 13 is a diagram of pile formation using the extrusion and expansion method of the present invention.

[0085] FIG. 14 is a diagram of the present invention of the extrusion and expansion method of synchronously withdrawing the bottom soil thread and then lifting the drill.

[0086] 15 is a diagram of the bottom threaded hole and the upper extruded pile hole of the extrusion and expansion method of the present invention.

[0087] FIG. 16 is a diagram showing pile formation by the extrusion and expansion method of the present invention.

[0088] Reference numerals: drill bit (1), upper connector plug (1-1), drill core tube (1-2), drill blade (1-3), conical drill gate (1-4),

[0089] Extruded body (2), cylindrical retaining body (2-1), special-shaped threaded extruded body (2-2), core tube (2-2-1), blades (2-2-2), Archimedean spiral surface (2-2-3), upper joint (2-2-4), pin shaft (4), lower joint (2-2-5), extruded body (22) in the same direction, cylindrical retaining body (22-1) in the same direction, core tube (22-2-1) in the same direction, blades (22-2-2) in the same direction, Archimedean spiral surface (22-2-3),

[0090] Reverse upward extrusion expansion body (23), reverse cylindrical retaining body (23-1), reverse core tube (23-2-1), reverse blade (23-2-2), reverse Archimedean spiral surface (23-2-3),

[0091] A connecting rod (3), a pin shaft (4), a pile frame (5), a power head (6), a column (7), a hoisting mechanism (8), a slewing mechanism (9), a diagonal brace (11), a platform (12), a chassis (13), a pulley block (14), a walking mechanism (15), and a counterweight (19). DETAILED DESCRIPTION

[0092] The present invention is described below in conjunction with the accompanying drawings and embodiments.

[0093] As attached Figure 1 , Attachment Figure 2As shown, an extrusion and expansion drilling tool comprises a drill bit (1), an extrusion and expansion body (2), a connecting rod (3), and a pin (4), characterized in that the extrusion and expansion body (2) is composed of a cylindrical retaining body (2-1) and a special-shaped threaded extrusion and expansion body (2-2), the special-shaped threaded extrusion and expansion body (2-2) comprises a core tube (2-2-1), blades (2-2-2) and an Archimedean spiral surface (2-2-3), the upper end of the core tube (2-2-1) is fixedly connected to the lower end of the connecting rod (3) through an extrusion and expansion upper joint (2-2-4) and a pin (4), and the lower end is fixedly connected to the drill bit (1), the upper part of the core tube (2-2-1) is connected in series with the cylindrical retaining body (2-1), and the lower part is spirally wound with equal-pitch blades (2-2-2) along the axis upward, and the cylindrical retaining body (2-1) is connected to the upper part of the core tube (2-2-1). The lower end of the column retaining body (2-1) is fixedly connected to the blade (2-2-2); the outer diameter of the cylindrical retaining body (2-1) is the same as the diameter of the blade (2-2-2); the Archimedean spiral surface (2-2-3) uses the radius of the core tube (2-2-1) as the minimum starting polar diameter and the distance between the connection points of two adjacent blades (2-2-2) and the core tube (2-2-1) generatrix as the starting width; the curved surface formed by winding between the two blades along the spiral trajectory of the blade (2-2-2) in the manner of an Archimedean spiral line is called the Archimedean spiral surface (2-2-3); the axial generatrix on the Archimedean spiral surface (2-2-3) is parallel to the axis of the core tube (2-2-1), and the Archimedean spiral surface During the winding process, the upper end of (2-2-3) is always fixedly connected to the lower end surface of the upper blade (2-2-2) of the adjacent blade, and the lower end is always fixedly connected to the upper end surface of the lower blade (2-2-2) of the adjacent blade. The polar diameter of the Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a cylindrical retaining body (2-1), so that the Archimedean spiral surface (2-2-3) has a cam effect during synchronous drilling and rotary soil extrusion, and at the same time, the cylindrical retaining body has the function of maintaining the aperture and stabilizing the axis of the drilling tool. The diameter of the connecting rod is not greater than the diameter of the cylindrical retaining body, so that the extrusion and expansion drilling tool reduces resistance during the rotary drilling process. The drill blades (1-3) and The blades (2-2-2) on the extrusion and expansion body (2) have the same outer diameter, thickness and lead, and the connection parts are butt-jointed to form a continuous equal-pitch blade (2-2-2). Synchronous drilling is adopted during drilling, so that after the drill bit (1) drills the hole, a soil thread is formed. The soil thread is gradually increased in situ by the Archimedean spiral surface (2-2-3) on the extrusion and expansion body (2) that rotates downward synchronously, which is equivalent to the cam polar diameter from small to large, so that the soil is squeezed into the side wall of the pile hole in situ, which significantly improves the pile quality. Finally, when the cylindrical retaining body (2-1) on the extrusion and expansion drill reaches the original position of the soil, the pile hole diameter is further maintained to meet the construction requirements. Since the diameter of the connecting rod is not larger than the cylindrical retaining body, the resistance of the extrusion and expansion drill is further reduced during the rotation and drilling process.In this way, the drilling is gradually continued until the pile hole reaches the designed depth.

[0094] As attached Figure 2 As shown, the present invention can be provided with an upper joint plug (1-1) at the upper end of the drill bit (1), and a lower joint (2-2-5) is provided at the lower end of the core tube (2-2-1) of the special-shaped threaded extrusion and expansion body (2-2). The upper joint plug (1-1) is fixedly connected to the lower joint (2-2-5) of the core tube (2-2-1) via a distribution shaft (4), so as to achieve the effect of expanding construction capacity and facilitating maintenance.

[0095] As attached Figure 2 As shown, the present invention may also be provided with a drill core tube (1-2) between the drill bit (1) and the upper joint plug (1-1), the drill core tube (1-2) being threaded with drill blades (1-3), the drill blades (1-3) and the blades (2-2-2) on the extrusion and expansion body (2) having the same outer diameter, thickness and lead, and the connection parts are butt-jointed to form a continuous equal-pitch blade (2-2-2), so as to achieve synchronous drilling to form soil threads and in-situ extrusion and expansion of the soil threads, reduce soil extrusion resistance, increase the drill bit length, meet the requirements of screw piles, and can be used for extrusion and expansion of screw pile holes.

[0096] As attached Figure 3 As shown, the outer wall of the cylindrical expansion body and the blade of the expansion body of the present invention is provided with a ventilation groove (15), and the ventilation groove (15) is axially arranged. At least two ventilation grooves (15) are arranged in an array along the outer circumference of the expansion body to facilitate the discharge of compressed gas sent into the bottom during the drilling process.

[0097] The connecting rod (3) of the present invention may be a bare rod, a long spiral drill rod, or a threaded drill rod, so as to be adaptable to different pile drivers.

[0098] As attached Figure 3 , Attachment Figure 4As shown, when part of the soil layer in the pile hole is very soft and the bottom of the pile hole is required to be a threaded hole, the present invention can also be provided with a coaxially connected unidirectional extrusion expansion body (22) between the extrusion expansion body (2) and the connecting rod (3), the unidirectional extrusion expansion body (22) mainly comprising a unidirectional core tube (22-2-1), unidirectional blades (22-2-2), unidirectional Archimedean spiral surfaces (22-2-3) and a unidirectional cylindrical retaining body (22-1), the upper end of the unidirectional core tube (22-2-1) is fixedly connected to the connecting rod (3) via a second upper joint and a second upper pin shaft, and the lower end is fixedly connected to the upper joint at the upper end of the extrusion expansion body (2) via a second lower joint and a second lower pin shaft, and the unidirectional blades (22-2-2) are axially spirally wound on the unidirectional core tube (22-2-1). ), a unidirectional cylindrical retaining body (22-1) is connected in series at the lower part of the unidirectional core tube (22-2-1), the outer diameter of the unidirectional cylindrical retaining body (22-1) is the same as the outer diameter of the cylindrical retaining body (2-1), the unidirectional Archimedean spiral surface (22-2-3) takes the radius of the unidirectional core tube (22-2-1) as the minimum starting pole diameter, takes the distance between the connection points of two adjacent unidirectional blades (22-2-2) and the generatrix of the unidirectional core tube (22-2-1) as the starting width, and starts from the first group of two unidirectional blades at the upper end of the unidirectional core tube (22-2-1), along the spiral trajectory of the unidirectional blades (22-2-2) and is wound between the two blades in the form of an Archimedean spiral line, which is called the unidirectional Archimedean spiral surface (22-2-3), and the unidirectional Archimedean spiral surface (22-2-3) is formed. The axial generatrix on the Archimedean spiral surface (22-2-3) is parallel to the axis of the same-direction core tube (22-2-1), and the upper end of the same-direction Archimedean spiral surface (22-2-3) is always fixedly connected to the lower end surface of the upper blade (22-2-2) of the adjacent same-direction blade during the winding process, and the lower end is always fixedly connected to the upper end surface of the lower blade (22-2-2) of the adjacent blade. The polar diameter of the same-direction Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a same-direction cylindrical retaining body (22-1), so that the same-direction Archimedean spiral surface (22-2-3) has a cam effect when rotating in the opposite direction to squeeze soil, so that the extrusion and expansion drilling tool reaches a set depth. After that, the rotation and drilling are synchronously stopped, and the control device instructs the winch mechanism and the power head to synchronously rotate in the opposite direction and lift to withdraw the thread. At this time, a threaded hole is formed at the bottom of the pile hole due to the synchronous withdrawal of the spiral blades of the extrusion and expansion drill. During the process of withdrawing the thread, when the loose soil on the pile hole side wall that has been squeezed and expanded at the upper part of the same-direction extrusion and expansion body (22) falls off, under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surface (22-2-3) on the same-direction extrusion and expansion body (22), the same-direction Archimedean spiral surface (22-2-3) has a cam effect when rotating in the opposite direction to squeeze the soil, and the fallen soil is radially squeezed into the pile hole side wall again, and the pile hole is shaped and maintained by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1).Until the extrusion and expansion drill moves upward and is lifted to the ground surface to form a screw pile hole. This not only reduces the resistance of the soil to the drill, but also prevents the soil falling from the side wall of the pile hole from falling out of the ground, significantly improving the quality of the pile hole.

[0099] As attached Figure 5 , Attachment Figure 6As shown, when the bottom of the pile hole is required to be a smooth hole, the present invention can also be provided with a reverse upper extrusion expansion body (23) coaxially connected between the extrusion expansion body (2) and the connecting rod (3), the reverse upper extrusion expansion body (23) mainly comprising a reverse core tube (23-2-1), reverse blades (23-2-2), a reverse Archimedean spiral surface (23-2-3) and a reverse cylindrical retaining body (23-1), the upper end of the reverse core tube (23-2-1) is fixedly connected to the connecting rod (3) via a third upper joint and a third upper pin, and the lower end is fixedly connected to the upper joint of the upper end of the extrusion expansion body (2) via a third lower joint and a third lower pin, the upper axial spiral of the reverse core tube (23-2-1) is provided with a reverse blade (23-2-2), and the lower end of the reverse core tube (23-2-1) is fixedly connected to the upper end of the extrusion expansion body (2) via a third lower joint and a third lower pin. The reverse cylindrical retaining body (23-1) is connected in series with the reverse cylindrical retaining body (23-1), the outer diameter of the reverse cylindrical retaining body (23-1) is the same as the outer diameter of the cylindrical retaining body (2-1), the reverse Archimedean spiral surface (23-2-3) uses the radius of the reverse core tube (23-2-1) as the minimum starting pole diameter, uses the distance between the connection points of two adjacent reverse blades (23-2-2) and the generatrix of the reverse core tube (23-2-1) as the starting width, and starts from the first group of two reverse blades at the upper end of the reverse core tube (23-2-1), along the spiral trajectory of the reverse blade (23-2-2) and forms a curved surface wound between the two blades in the manner of an Archimedean spiral line, which is called the reverse Archimedean spiral surface (23-2-3). The axial generatrix on the reverse Archimedean spiral surface (23-2-3) is The reverse Archimedean spiral surface (23-2-3) is parallel to the axis of the reverse core tube (23-2-1), and the upper end of the reverse Archimedean spiral surface (23-2-3) is always fixedly connected to the lower end surface of the upper blade (23-2-2) of the adjacent reverse blade during the winding process, and the lower end is always fixedly connected to the upper end surface of the lower blade (23-2-2) of the adjacent reverse blade. The polar diameter of the reverse Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a reverse cylindrical retaining body (23-1), so that the reverse Archimedean spiral surface (23-2-3) has a cam effect when rotating and squeezing soil in the positive direction, so that after the squeezing and expanding drill tool reaches the set depth, the control device instructs to stop drilling, and the power head continues to The extrusion and expansion drill bit rotates in the same direction during drilling. At this time, the soil thread at the bottom of the pile hole is sheared off in situ to form a smooth hole. After the extrusion and expansion drill bit rotates for at least one circle, the drill bit is lifted upward, and the power head continues to rotate in the same direction as the drilling. During the upward lifting process, when the loose soil on the pile hole side wall that has been squeezed and expanded at the upper part of the reverse extrusion and expansion body (23) falls, the reverse blades (23-2-2) and the reverse Archimedean spiral surface (23-2-3) on the reverse extrusion and expansion body (23) radially squeeze the fallen soil into the pile hole side wall again, and the pile hole is shaped and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill bit moves upward to the ground surface to form an extrusion and expansion pile smooth hole, which not only improves the extrusion and expansion rate but also reduces the resistance of the soil to the drill bit.It also significantly improves the pile hole quality.

[0100] As attached Figure 3 As shown, the present invention can provide a second ventilation groove (16) on the outer wall of the same-direction cylindrical extrusion body and the same-direction blade of the same-direction extrusion body, and the second ventilation groove (16) is axially arranged, and the second ventilation groove (16) is connected with the first ventilation groove to form the same air outlet groove, so that the gas is discharged along the first ventilation groove (15) and the second ventilation groove (16).

[0101] As attached Figure 5 As shown, the present invention can provide ventilation groove three (17) on the outer wall of the reverse cylindrical extrusion body and the reverse blade of the reverse extrusion body, and the ventilation groove three (17) is axially arranged, and the ventilation groove three (17) is connected with the ventilation groove one (15) to form the same air outlet groove, so that the gas can be discharged along the ventilation groove one (15) and the ventilation groove three (17).

[0102] As attached Figure 2 , Attachment Figure 7 As shown, when it is necessary to lengthen the threaded hole, the drill bit (1) can be replaced, or a threaded drill rod section (31) with the same pitch to form an integral thread can be added between the lower joint of the core tube (2-2-1) of the extrusion and expansion drilling tool and the drill bit (1), the core tube of the threaded drill rod section (31) has the same shape and diameter as the core tube of the drill bit on the drill bit, the spiral blades on the threaded drill rod section (31) have the same outer diameter, thickness and lead as the drill blades (1-3) on the drill bit, and after connection, the blades on the threaded drill rod section (31) are butted with the special-shaped threaded extrusion and expansion body and the drill bit to form a continuous equal-pitch blade (2-2-2), and the ventilation groove three provided on the outer wall of the blade of the threaded drill rod section (31) is butted with the ventilation groove one and the ventilation groove two to form the same air outlet groove, so as to reduce the resistance to extrusion and increase the length of the bottom threaded hole, or to meet the requirements of the screw pile and form an extrusion and expansion screw pile hole.

[0103] The invention utilizes the gradually enlarged Archimedean spiral surface (2-2-3) to squeeze and expand in situ during the synchronous drilling process, so that the soil is not sheared, not transported upward, and does not use the truncated cone body to squeeze and generate upward resistance. The radial situ squeezing greatly reduces the resistance applied to the drill tool during the drilling process, and solves the substantial technical problems that the cross section of the squeezing and expanding body of the truncated cone structure is circular in the cross section perpendicular to the axis line of the drill tool, the squeezing and expanding body of the truncated cone structure has no squeezing and expanding effect when the drill tool performs a rotary motion, and the truncated cone body inclined surface generates a component force to squeeze the soil downward, resulting in the compaction of the lower soil body, resulting in large resistance, making it difficult for the drill tool to drill, and resulting in low squeezing and expanding efficiency; at the same time, it also solves the substantial problem that the spiral blade rotates the soil out, and then uses the spiral blade to perform a spiral propulsion motion in the reverse direction to send it into the squeezing and expanding body, which consumes a lot of power; it also solves the substantial problem that the soil is squeezed within the pile length range to form a straight rod nut-shaped soil body, and then the drill rod is asynchronously rotated forward in situ to squeeze the nut soil body, which consumes a lot of power.

[0104] As attached Figure 8 As shown, a pile extrusion and expansion machine comprises a pile frame (5) and a power head (6), wherein the pile frame (5) is provided with a column (7), a diagonal brace (11), a platform (12), a chassis (13), a counterweight (19), a pulley block (14), a traveling mechanism (15), a hoisting mechanism (8), a slewing mechanism (9), a hydraulic system, an operating table and a control device, wherein the connection relationship between the column (7), the diagonal brace (11), the platform (12), the chassis (13), the counterweight (19), the pulley block (14), the traveling mechanism (15), the power head (6), the hoisting mechanism (8), the slewing mechanism (9), the hydraulic system, the power supply, the operating table and the control device is the prior art and is not described in detail herein, and the pile extrusion and expansion machine is characterized in that it also comprises any one of the extrusion and expansion drilling tools described above.

[0105] The control device of the present invention may include a PLC synchronous controller, a drill tool frequency converter and a winch frequency converter. The connection structure of the PLC synchronous controller, the drill tool frequency converter and the winch frequency converter is the same as that of Patent No.: 2010105514658, Patent Name: PLC Controlled Variable Frequency Pile Driver, which will not be repeated here.

[0106] The control device may also adopt a hydraulic synchronous control system, which is a prior art and will not be described in detail here.

[0107] The control device may also adopt a DC motor synchronous control system, which is a prior art and will not be described in detail here.

[0108] The control device can also adopt any hybrid synchronous control system among AC, DC and hydraulic. The hybrid synchronous control system is a prior art and will not be described in detail here.

[0109] A method for forming piles by squeezing and expanding piles, characterized in that the method comprises the following steps:

[0110] 1) As shown in Figure 9, the pile extrusion and expansion machine is in place.

[0111] An extrusion and expansion drilling tool consisting of a connecting rod (3), an extrusion and expansion body (2), a drill bit (1) and a pin shaft (4) is fixed to the lower joint of the power head of the extrusion and expansion pile driver;

[0112] 2) As shown in Figures 10 and 11, the front end of the soil is drilled into a soil thread hole, and the rear end of the soil thread is squeezed and expanded in situ into a light hole.

[0113] After the pile driver is installed in place, the control device starts the power head (6) and the hoisting mechanism (8) at the same time to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the pile driver downward by one pitch for synchronous drilling. During the synchronous drilling process of the pile driver, the drill bit (1) of the pile driver drills the soil into a threaded hole. During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped threaded pile driver (2-2) that is rotated downward in situ and formed on the soil is gradually squeezed into the side wall of the pile hole, and the formed pile hole is continuously maintained in compliance with the construction requirements by the cylindrical retaining body (2-1) on the special-shaped threaded pile driver (2-2). During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped threaded pile driver (2-2) is gradually squeezed into the side wall of the pile hole by the Archimedean spiral surface (2-2-3) on the special-shaped threaded pile driver (2-2). The polar diameter of the Archimedean spiral surface (2-2-3) gradually increases, which is equivalent to the polar diameter of the cam increasing from small to large to squeeze the soil into the side wall of the pile hole in situ, so that the resistance of the power head (6) is only the friction between the squeezing and expanding body and the soil on the pile hole wall and the squeezing resistance on the hole wall, and no resistance of shearing the soil is generated after the soil is transported, thereby reducing the construction resistance and greatly improving the construction efficiency. Since the polar diameter of the Archimedean spiral surface (2-2-3) on the squeezing and expanding body (2) gradually increases, which is equivalent to the polar diameter of the cam increasing from small to large to squeeze the soil into the side wall of the pile hole in situ, the squeezing and expanding space at the front end of the squeezing and expanding body (2) is small, and the squeezing and expanding space at the rear end is large. Once the drill is stuck or buried, the drill bit is reversed to make the front end of the squeezing and expanding body (2) withdraw from the position with small squeezing and expanding space to the position with large squeezing and expanding space at the rear end, and the withdrawal resistance is small, so that the drill is not stuck or buried, and the construction efficiency and pile quality are significantly improved;

[0114] Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached;

[0115] 3) As shown in Figure 12, the soil thread at the bottom is sheared and the drill is lifted.

[0116] After the drill is lifted, a light hole of the squeezed and expanded pile is formed.

[0117] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the hoisting mechanism (8) to stop lowering the extrusion and expansion drill bit. At the same time, the power head (6) continues to rotate and applies torque in the same direction as when the extrusion and expansion drill bit is drilled down, so that the extrusion and expansion drill bit rotates in situ, and the bottom soil thread that the cylindrical retaining body (2-1) has not reached is sheared. After the extrusion and expansion drill bit rotates for at least one circle, the control device controls the hoisting mechanism (8) to lift the power head (6) so that the extrusion and expansion drill bit moves upward until it reaches the ground surface;

[0118] During construction, this method does not form an integral threaded hole. Instead, the soil threaded hole is formed by drilling in situ in the soil while expanding the soil thread into a smooth hole. After drilling to the designed depth, only the soil portion that is not reached by the cylindrical retaining body (2-1) is not expanded. At this time, it is sheared, which greatly reduces the shear torque and improves the construction efficiency. Compared with the existing technology, the implementation of this method will greatly reduce energy consumption and carbon emissions. It is a green, energy-saving, environmentally friendly and efficient construction method.

[0119] 4) Piling is performed as shown in Figure 13.

[0120] When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a concrete pile;

[0121] Alternatively, after the extrusion and expansion drill tool moves upward and is lifted to the ground surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile; Alternatively, after the extrusion and expansion drill tool moves upward and is lifted to the ground surface, fillers are poured into the hole and the pile is expanded by tamping. Since the soil is fully squeezed and expanded, the density of the pile hole is high, which greatly improves the bearing capacity of the pile.

[0122] The lower joint of the power head of the pile extrusion and expansion machine of the present invention is fixed as follows Figure 5 In the construction of step 3) when the bottom of the pile hole is a bare hole, a reverse upper extrusion and expansion body (23) can be coaxially connected between the extrusion and expansion body (2) and the connecting rod (3). During the upward lifting process, the extrusion and expansion drill tool maintains the rotation direction when drilling down and continues to rotate. When the loose soil on the side wall of the pile hole after extrusion and expansion falls off, the reverse blades (23-2-2) and the reverse Archimedean spiral surface (23-2-3) on the reverse upper extrusion and expansion body (23) radially squeeze the fallen soil into the pile again. The side wall of the hole is formed and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill moves upward to the ground surface to form an extrusion and expansion pile hole. Since the reverse upward extrusion and expansion body (23) adopts a cam structure with an Archimedean spiral surface, it radially squeezes the soil, does not generate an upward thrust on the soil, and does not rely on the downward conveying of the soil to be squeezed by a truncated cone, and squeezes out space for the soil falling downward, so that the falling soil is gradually squeezed and expanded by the upward reverse upward extrusion and expansion body (23), achieving a good extrusion and expansion effect. The resistance of the soil to the drill is reduced, and the soil falling from the side wall of the pile hole is prevented from falling and being carried out of the ground, which significantly improves the extrusion and expansion efficiency and the pile quality.

[0123] A method for forming piles by squeezing and expanding piles, characterized in that the method comprises the following steps:

[0124] 1) As shown in Figure 9, the pile extrusion and expansion machine is in place.

[0125] The joint under the power head of the pile extruder is fixed as follows Figure 1 The extrusion and expansion drilling tool shown;

[0126] 3) As shown in Figures 10 and 11, the front end of the soil is drilled synchronously to form a soil thread hole, and the rear end soil thread is squeezed and expanded in situ to form a light hole.

[0127] After the pile extrusion and expansion machine is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward by one lead for synchronous drilling. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills the soil into a threaded hole. During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped thread extrusion and expansion body (2-2) of the extrusion and expansion drill tool, which is rotated downward in situ, gradually squeezes the thread formed on the soil into the side wall of the pile hole, and the cylindrical retaining body (2-1) on the special-shaped thread extrusion and expansion body (2-2) continues to maintain the formed pile hole in compliance with the construction requirements.

[0128] Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached;

[0129] 3) As shown in Figures 14 and 15, the bottom soil thread is synchronously withdrawn and the drill is lifted.

[0130] After the drill is lifted, a threaded hole is formed at the bottom and a pile hole is squeezed and expanded at the top.

[0131] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the power head (6) and the hoisting mechanism (8) to synchronously stop drilling downwards. At the same time, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) in the reverse direction, so that each time the power head (6) rotates in the reverse direction, the hoisting mechanism (8) lifts the power head (6) and the extrusion and expansion drill tool up by one pitch, and after continuous operation, the extrusion and expansion drill tool synchronously exits the threaded section at the bottom, and is lifted to the ground surface; a threaded extrusion and expansion pile hole is formed at the bottom of the pile hole, and an extrusion and expansion pile hole is formed at the top; the threaded extrusion and expansion pile hole is left at the bottom of the pile hole, so that the side touch resistance of the pile can be increased, and the bearing capacity of the pile can be effectively increased, so that the construction of the screw pile can be completed;

[0132] 4) Piles are formed as shown in Figure 16.

[0133] When the extrusion and expansion drill tool begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a friction pile. Since the bottom of the pile hole is a threaded hole, the threaded extrusion and expansion pile at the bottom of the concrete pile forms a holding force on the soil, which greatly increases the stability of the pile and improves the bearing capacity.

[0134] Alternatively, after the extrusion and expansion drill moves upward and is lifted to the surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile;

[0135] Alternatively, when the extrusion and expansion drilling tool moves upward and is lifted to the surface, filler is poured into the hole and rammed to form a pile.

[0136] When screw pile construction is required, the present invention can replace the drill bit (1), or add equidistant threaded drill rod sections (31) between the lower joint of the core tube (2-2-1) of the extrusion and expansion drill and the drill bit (1) to increase the bottom thread length to meet the screw pile requirements, so that screw pile construction can be carried out to form screw extrusion and expansion piles.

[0137] When the present invention performs step 3) of returning the pile when the bottom of the pile hole is a threaded hole, the threaded section is gradually withdrawn during the reverse synchronous lifting process, and the extrusion and expansion drill tool maintains the rotation direction of the withdrawn threaded section and continues to rotate. When the loose soil part of the pile hole side wall on the upper part of the same-direction extrusion and expansion body (22) after being extruded and expanded falls off, the fallen soil is radially squeezed into the pile hole side wall again under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surface (22-2-3) on the same-direction extrusion and expansion body (22), and the pile hole is shaped and held by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill tool moves upward and is lifted to the ground surface to form a screw pile hole, thereby achieving a significant extrusion and expansion effect, reducing the resistance of the soil to the drill tool, and preventing the soil falling off the pile hole side wall from falling off and being carried out of the ground, thereby significantly improving the pile hole quality.

[0138] Embodiment 1: The present invention is used in the construction of polished hole extrusion piles.

[0139] 1) As shown in Figure 9, the pile extrusion and expansion machine is in place.

[0140] The extrusion and expansion drilling tool fixed at the lower end of the power head (6) of the extrusion and expansion pile driver according to the diameter required for construction comprises a connecting rod (3), an extrusion and expansion body (2), and a drill bit (1) in sequence, which are fixedly connected to each other by a pin shaft (4).

[0141] 2) As shown in Figures 10 and 11, the front end of the soil is drilled into a soil thread hole, and the rear end of the soil thread is squeezed and expanded in situ into a light hole.

[0142] After the extrusion and expansion pile driver is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward for synchronous drilling of one lead. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills a threaded hole in the soil, and the special-shaped threaded extrusion and expansion body (2-2) of the extrusion and expansion drill tool rotates downward in situ to form a threaded hole formed in the soil during the synchronous drilling process. The Archimedean spiral surface (2-2-3) on the special-shaped threaded extrusion and expansion body (2-2) is gradually squeezed into the side wall of the pile hole, and the formed pile hole continues to be maintained in compliance with the construction requirements by the cylindrical retaining body (2-1) on the special-shaped threaded extrusion and expansion body (2-2); during the synchronous drilling process, the polar diameter of the Archimedean spiral surface (2-2-3) on the extrusion and expansion body (2) gradually increases, which is equivalent to the polar diameter of the cam increasing from small to large to squeeze the soil in situ into the side wall of the pile hole, and the above-mentioned actions are repeated synchronously until the designed depth of the pile hole is reached;

[0143] 3) As shown in Figure 12, the soil thread at the bottom is sheared and the drill is lifted.

[0144] After the drill is lifted, a light hole of the squeezed and expanded pile is formed.

[0145] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the hoisting mechanism (8) to stop lowering the extrusion and expansion drill bit. At the same time, the rotary power head (6) continues to rotate and applies torque in the same direction as when the extrusion and expansion drill bit is drilled down, so that the extrusion and expansion drill bit rotates in situ, and the soil threads that are not reached by the cylindrical retaining body (2-1) are sheared. After the extrusion and expansion drill bit rotates for at least one circle, the control device controls the hoisting mechanism (8) to lift the power head (6) so that the extrusion and expansion drill bit moves upward until it reaches the ground surface.

[0146] 4) Piling is performed as shown in Figure 13.

[0147] When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a concrete pile, which greatly increases the bearing capacity of the pile.

[0148] Alternatively, after the extrusion and expansion drill bit is moved upward and lifted to the ground surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form piles.

[0149] Example 2: When the pile extrusion and expansion machine is constructing the pile extrusion and expansion at the top of the bottom threaded hole,

[0150] 1) As shown in Figure 9, the pile extrusion and expansion machine is in place.

[0151] The extrusion and expansion drilling tool fixed at the lower end of the power head (6) of the extrusion and expansion pile driver has a diameter according to the construction requirements and comprises a connecting rod (3), an extrusion and expansion body (2), and a drill bit (1) in sequence, which are fixedly connected to each other by a pin shaft (4).

[0152] 2) As shown in Figures 10 and 11, the front end of the soil is drilled into a soil thread hole, and the rear end of the soil thread is squeezed and expanded in situ into a light hole.

[0153] After the extrusion and expansion pile driver is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward for synchronous drilling of one lead. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills a threaded hole in the soil, and the special-shaped threaded extrusion and expansion body (2-2) of the extrusion and expansion drill tool rotates downward in situ to form a threaded hole formed in the soil during the synchronous drilling process. The Archimedean spiral surface (2-2-3) on the special-shaped threaded extrusion and expansion body (2-2) is gradually squeezed into the side wall of the pile hole, and the formed pile hole continues to be maintained in compliance with the construction requirements by the cylindrical retaining body (2-1) on the special-shaped threaded extrusion and expansion body (2-2); during the synchronous drilling process, the polar diameter of the Archimedean spiral surface (2-2-3) on the extrusion and expansion body (2) gradually increases, which is equivalent to the polar diameter of the cam increasing from small to large to squeeze the soil in situ into the side wall of the pile hole, and the above-mentioned actions are repeated synchronously until the designed depth of the pile hole is reached;

[0154] 3) As shown in Figures 14 and 15, the bottom soil thread is synchronously withdrawn and the drill is lifted.

[0155] After the drill is lifted, a threaded hole is formed at the bottom and a pile hole is squeezed and expanded at the top.

[0156] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the power head (6) and the hoisting mechanism (8) to synchronously stop drilling downwards. At the same time, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) in the reverse direction, so that each time the power head (6) rotates in the reverse direction, the hoisting mechanism (8) lifts the power head (6) and the extrusion and expansion drill tool up by one pitch, and after continuous operation, the extrusion and expansion drill tool synchronously exits the threaded section at the bottom, and is lifted to the ground surface after moving upwards and synchronously exiting the threaded section, so that a threaded extrusion and expansion pile hole is formed at the bottom of the pile hole, and an extrusion and expansion pile hole is formed at the top;

[0157] 4) Piling as shown in Figure 16

[0158] When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a friction pile, which greatly increases the friction resistance of the pile and improves the bearing capacity;

[0159] Alternatively, after the extrusion and expansion drill moves upward and is lifted to the surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile;

[0160] Alternatively, after the extrusion and expansion drill tool is moved upward and lifted to the surface, filler is poured into the hole and the pile is rammed and expanded, which greatly improves the bearing capacity of the rammed and expanded pile.

[0161] When it is necessary to lengthen the threaded hole, the drill bit (1) can be replaced, or a threaded drill rod section (31) with the same thread pitch and an integral thread can be added between the lower joint of the core tube (2-2-1) of the extrusion and expansion drilling tool and the drill bit (1), so as to reduce the resistance to soil extrusion and increase the length of the bottom threaded hole, or to form an extrusion and expansion screw pile hole to meet the requirements of the screw pile.

[0162] Embodiment 3: When the present invention is used to perform pile extrusion and expansion, if there is a loose soil layer, a connecting rod, a reverse extrusion and expansion body, an extrusion and expansion body and a drill bit can be fixedly connected in sequence at the lower end of the power head of the pile extrusion and expansion machine, and they are fixedly connected to each other via a distribution shaft.

[0163] 1) Pile driver placement and 2) synchronous drilling are the same as in Example 1 and will not be described in detail.

[0164] 3) Back-piling and squeezing to form a light hole at the bottom of the pile hole:

[0165] When the pile driver continues to drill to the designed depth of the pile hole, the controller controls the hoisting mechanism (8) to stop lowering the extrusion and expansion drill bit. At the same time, the rotary power head (6) continues to rotate and applies torque in the same direction as when the extrusion and expansion drill bit was drilled down, so that the extrusion and expansion drill bit rotates in situ. The soil portion not reached by the cylindrical retaining body (2-1) is sheared. The extrusion and expansion drill bit continues to rotate. The control device controls the hoisting mechanism (8) to lift the power head (6). During the upward lifting process, the extrusion and expansion drill bit continues to rotate in the direction of rotation when drilling down. When the loose soil portion of the pile hole side wall that has been squeezed and expanded falls off, the reverse blades (23-2-2) and the reverse extrusion and expansion body (23) on the reverse direction are Under the action of the reverse Archimedean spiral surface (23-2-3), the fallen soil is radially squeezed into the side wall of the pile hole again, and the pile hole is shaped and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drill moves upward to the ground surface to form an extrusion and expansion pile hole. Since the reverse upper extrusion and expansion body (23) adopts a cam structure with an Archimedean spiral surface, it radially squeezes the soil without generating an upward thrust on the soil, and does not rely on the downward conveying of the soil to be squeezed by a truncated cone, so that space is squeezed out for the soil falling downward, so that the fallen soil is gradually squeezed and expanded by the upward reverse upper extrusion and expansion body (23), achieving a significant squeezing and expansion effect.

[0166] 4) Piling is the same as in Example 1 and will not be described in detail here.

[0167] Embodiment 4: In order to prevent loose soil from falling into the pile hole during the extrusion and expansion of the threaded pile hole, the present invention can sequentially connect a connecting rod, an extrusion and expansion body in the same direction, an extrusion and expansion body and a drill bit to the lower end of the extrusion and expansion pile driver power head, and the extrusion and expansion bodies and the drill bits are connected to each other via a distribution shaft.

[0168] 1) Pile driver placement and 2) synchronous drilling are the same as in Example 2 and will not be described in detail.

[0169] 3) Formation of bottom threaded hole

[0170] When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the power head (6) and the hoisting mechanism (8) to synchronously stop rotating and lower the extrusion and expansion drilling tool. At the same time, the power head (6) and the hoisting mechanism (8) are synchronously rotated in the opposite direction to lift the power head (6). During the reverse synchronous lifting process, the threaded section is gradually withdrawn, and the extrusion and expansion drilling tool continues to rotate in the direction of withdrawal from the threaded section. When the loose soil on the upper pile hole side wall of the extrusion and expansion body (22) falls off, the soil on the extrusion and expansion body (22) is squeezed and expanded. Under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surfaces (22-2-3), the fallen soil is radially squeezed into the side wall of the pile hole again, and the pile hole is shaped and retained by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1) until the squeezing and expanding drill moves upward and is lifted to the ground surface to form a screw pile hole, which has a significant squeezing and expanding effect, reduces the resistance of the soil to the drill, avoids the soil that falls from the side wall of the pile hole from falling and being carried out of the ground, and significantly improves the pile quality of the pile hole.

[0171] When it is necessary to lengthen the threaded hole, the drill bit (1) can be replaced, or a threaded drill rod section (31) with the same thread pitch and an integral thread can be added between the lower joint of the core tube (2-2-1) of the extrusion and expansion drilling tool and the drill bit (1), so as to reduce the resistance to soil extrusion and increase the length of the bottom threaded hole, or to form an extrusion and expansion screw pile hole to meet the requirements of the screw pile.

[0172] 4) Piling is the same as in Example 2 and will not be described in detail here.

[0173] Due to the adoption of the above structure and construction method, the present invention achieves synchronous drilling and squeezing during the drilling process, and there is no need to squeeze the soil within the pile length range to form a straight rod nut-shaped soil body, which greatly reduces the resistance, significantly improves the construction effect, and achieves high pile quality; there is no need to rotate the soil out, and the soil does not need to perform spiral motion from bottom to top; the soil is gradually squeezed into the side wall of the pile hole in situ by the Archimedean spiral surface under the synchronous action of drilling and rotation, and has the advantages of high construction efficiency, low power consumption, good soil squeezing effect, higher pile quality, no drill jamming, buried drill, long service life, etc.

[0174] The same direction cylindrical expansion body, the same direction core tube, the same direction blades, the same direction Archimedean spiral surface, the reverse core tube (23-2-1), the reverse blades (23-2-2), the reverse Archimedean spiral surface (23-2-3) and the reverse cylindrical retaining body (23-1) referred to in the present invention, the "reverse" and "same direction" here are only used to distinguish other parts and do not represent directions, and are hereby explained.

[0175] The axial generatrix described in the present invention is defined as: a line connecting the outer end points of the same polar diameter on the Archimedean spiral surface.

Claims

1. An extrusion and expansion drilling tool, comprising a drill bit (1), an extrusion and expansion body (2), a connecting rod (3), and a pin (4), characterized in that The extrusion expansion body (2) is composed of a cylindrical retaining body (2-1) and a special-shaped thread extrusion expansion body (2-2); the special-shaped thread extrusion expansion body (2-2) comprises a core tube (2-2-1), blades (2-2-2) and an Archimedean spiral surface (2-2-3); the upper end of the core tube (2-2-1) is fixedly connected to the lower end of a connecting rod (3) via an extrusion expansion upper joint (2-2-4) and a pin shaft (4); the lower end is fixedly connected to a drill bit (1); the upper end of the core tube (2-2-1) is fixedly connected to the drill bit (1); The upper part is connected in series with a cylindrical retaining body (2-1), and the lower part is spirally wound with equal-pitch blades (2-2-2) along the axis upwards, the lower end of the cylindrical retaining body (2-1) is fixedly connected to the blades (2-2-2), the outer diameter of the cylindrical retaining body (2-1) is the same as the diameter of the blades (2-2-2), and the Archimedean spiral surface (2-2-3) uses the radius of the core tube (2-2-1) as the minimum starting pole diameter and the generatrix of two adjacent blades (2-2-2) and the core tube (2-2-1) as the minimum starting pole diameter. The distance between the connection points is the starting width. The curved surface formed by winding between the two blades along the spiral trajectory of the blade (2-2-2) in the manner of an Archimedean spiral line starting from the lower end of the core tube (2-2-1) is called the Archimedean spiral surface (2-2-3). The axial generatrix on the Archimedean spiral surface (2-2-3) is parallel to the axis of the core tube (2-2-1), and the upper end of the Archimedean spiral surface (2-2-3) is always aligned with the upper blade (2-2 -2) the lower end face is fixedly connected, the lower end is always fixedly connected to the upper end face of the lower blade (2-2-2) of the adjacent blade, the polar diameter of the Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a cylindrical retaining body (2-1), so that the Archimedean spiral surface (2-2-3) has a cam effect during synchronous drilling and rotary soil squeezing, and the diameter of the connecting rod is not greater than the diameter of the cylindrical retaining body.

2. The extrusion and expansion drilling tool according to claim 1, characterized in that An upper joint plug (1-1) is provided at the upper end of the drill bit (1), a lower joint (2-2-5) is provided at the lower end of the core tube (2-2-1) of the special-shaped threaded extrusion and expansion body (2-2), and the upper joint plug (1-1) is fixedly connected to the lower joint (2-2-5) of the core tube (2-2-1) via a distribution shaft (4).

3. The extrusion and expansion drilling tool according to claim 2, characterized in that A drill core tube (1-2) is provided between the drill bit (1) and the upper joint plug (1-1); a drill blade (1-3) is threadedly wound on the drill core tube (1-2); the drill blade (1-3) and the blade (2-2-2) on the extrusion expansion body (2) have the same outer diameter, thickness and lead, and the connection parts are butt-jointed to form a continuous blade (2-2-2) with equal pitch.

4. The extrusion and expansion drilling tool according to claim 3, characterized in that The cylindrical expansion body and the outer wall of the blade of the expansion body are provided with a ventilation groove (15), and the ventilation groove (15) is axially arranged.

5. The extrusion and expansion drilling tool according to claim 4, characterized in that A unidirectional extrusion expansion body (22) is coaxially connected between the extrusion expansion body (2) and the connecting rod (3). The unidirectional extrusion expansion body (22) mainly comprises a unidirectional core tube (22-2-1), unidirectional blades (22-2-2), unidirectional Archimedean spiral surfaces (22-2-3) and a unidirectional cylindrical retaining body (22-1). The upper end of the unidirectional core tube (22-2-1) is fixedly connected to the connecting rod (3) via a second upper joint and a second upper pin shaft, and the lower end is fixedly connected to the upper joint of the upper end of the extrusion expansion body (2) via a second lower joint and a second lower pin shaft. The unidirectional core tube (22-2-1) is fixedly connected to the head, the unidirectional blades (22-2-2) are axially spirally wound on the unidirectional core tube (22-2-1), the lower part of the unidirectional core tube (22-2-1) is connected in series with a unidirectional cylindrical retaining body (22-1), the outer diameter of the unidirectional cylindrical retaining body (22-1) is the same as the outer diameter of the cylindrical retaining body (2-1), and the unidirectional Archimedean spiral surface (22-2-3) uses the radius of the unidirectional core tube (22-2-1) as the minimum starting pole diameter and the radius of two adjacent unidirectional blades (22-2-2) and the unidirectional core tube ( The spacing between the connection points of the busbars 22-2-1) is the starting width. The curved surface formed by winding between the two unidirectional blades of the first group at the upper end of the unidirectional core tube (22-2-1) along the spiral trajectory of the unidirectional blade (22-2-2) in the manner of an Archimedean spiral is called the unidirectional Archimedean spiral surface (22-2-3). The axial busbar on the unidirectional Archimedean spiral surface (22-2-3) is parallel to the axis of the unidirectional core tube (22-2-1), and the unidirectional Archimedean spiral surface (22-2-3) is wound. During the process, its upper end is always fixedly connected to the lower end surface of the upper blade (22-2-2) of the adjacent same-direction blade, and its lower end is always fixedly connected to the upper end surface of the lower blade (22-2-2) of the adjacent blade. The polar diameter of the same-direction Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral track with the maximum polar diameter as the radius to form a same-direction cylindrical retaining body (22-1), so that the same-direction Archimedean spiral surface (22-2-3) has a cam effect when rotating in the opposite direction to squeeze soil.

6. The extrusion and expansion drilling tool according to claim 4, characterized in that A reverse upper extrusion expansion body (23) is coaxially connected between the extrusion expansion body (2) and the connecting rod (3); the reverse upper extrusion expansion body (23) mainly comprises a reverse core tube (23-2-1), reverse blades (23-2-2), a reverse Archimedean spiral surface (23-2-3) and a reverse cylindrical retaining body (23-1); the upper end of the reverse core tube (23-2-1) is fixedly connected to the connecting rod (3) via a third upper joint and a third upper pin, and the lower end is fixedly connected to the extrusion expansion body via a third lower joint and a third lower pin. (2) The upper joint at the upper end is fixedly connected, the reverse core tube (23-2-1) is axially spirally wound with a reverse blade (23-2-2), the lower part of the reverse core tube (23-2-1) is serially connected with a reverse cylindrical retaining body (23-1), the outer diameter of the reverse cylindrical retaining body (23-1) is the same as the outer diameter of the cylindrical retaining body (2-1), and the reverse Archimedean spiral surface (23-2-3) takes the radius of the reverse core tube (23-2-1) as the minimum starting pole diameter and the radius of the two adjacent reverse core tubes (23-2-1) as the minimum starting pole diameter. The distance between the connection points of the blades (23-2-2) and the generatrix of the reverse core tube (23-2-1) is the starting width. The curved surface formed by winding between the two blades in the manner of an Archimedean spiral line along the spiral trajectory of the reverse blade (23-2-2) is called the reverse Archimedean spiral surface (23-2-3). The axial generatrix on the reverse Archimedean spiral surface (23-2-3) is parallel to the axis of the reverse core tube (23-2-1). The reverse Archimedean spiral surface (23-2-3) is parallel, and during the winding process, its upper end is always fixedly connected to the lower end surface of the upper blade (23-2-2) of the adjacent reverse blade, and its lower end is always fixedly connected to the upper end surface of the lower blade (23-2-2) of the adjacent reverse blade. The polar diameter of the reverse Archimedean spiral surface increases from small to large until its maximum polar diameter coincides with the outer diameter of the same-direction blade, and after the coincidence, it rotates at least one circle along the spiral trajectory with the maximum polar diameter as the radius to form a reverse cylindrical retaining body (23-1).

7. The extrusion and expansion drilling tool according to claim 5, characterized in that The outer walls of the same-direction cylindrical extrusion body and the same-direction blades of the same-direction extrusion body are provided with a second ventilation groove (16), the second ventilation groove (16) is axially arranged, and the second ventilation groove (16) is connected with the first ventilation groove to form the same air outlet groove.

8. The extrusion and expansion drilling tool according to claim 6, characterized in that The outer walls of the reverse cylindrical extrusion body and the reverse blade of the reverse upper extrusion body are provided with ventilation groove three (17), the ventilation groove three (17) is axially arranged, and the ventilation groove three (17) is connected with the ventilation groove one (15) to form the same air outlet groove.

9. The extrusion and expansion drilling tool according to claim 7, characterized in that A threaded drill rod section (31) with the same pitch is added between the lower joint of the core tube (2-2-1) of the extrusion and expansion drilling tool and the drill bit (1) to form an integral thread; the core tube of the threaded drill rod section (31) has the same shape and diameter as the drill core tube on the drill bit; the spiral blades on the threaded drill rod section (31) have the same outer diameter, thickness and lead as the drill blades (1-3) on the drill bit; and after connection, the blades on the threaded drill rod section (31) are butted with the special-shaped threaded extrusion and expansion body and the drill bit to form a continuous blade (2-2-2) with equal pitch.

10. A pile driver, comprising a pile frame (5) and a power head (6), wherein the pile frame (5) is provided with a column (7), a diagonal brace (11), a platform (12), a chassis (13), a counterweight (19), a pulley block (14), a traveling mechanism (15), a winch mechanism (8), a slewing mechanism (9), a hydraulic system, an operating table and a control device, characterized in that It also includes the extrusion and expansion drilling tool as described in any one of claims 1 to 9.

11. A method for forming piles by squeezing and expanding piles, characterized in that The steps of pile construction method include: 1) The pile extrusion machine is in place. The extrusion and expansion drilling tool as claimed in any one of claims 1 to 4 is fixed to the lower joint of the power head of the extrusion and expansion pile driver; 2) Synchronous drilling: the front end of the soil is drilled into a soil thread hole, and the rear end of the soil thread is squeezed and expanded into a smooth hole in situ. After the extrusion and expansion pile driver is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward by one lead for synchronous drilling. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills the soil into a threaded hole. During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped threaded extrusion and expansion body (2-2) of the extrusion and expansion drill tool, which is rotated downward in situ, gradually squeezes the thread formed on the soil into the side wall of the pile hole, and the cylindrical retaining body (2-1) on the special-shaped threaded extrusion and expansion body (2-2) continues to maintain the formed pile hole in compliance with the construction requirements. Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached; 3) The soil threads at the bottom are sheared and the drill is lifted. After the drill is lifted, a light hole of the squeezed pile is formed. When the pile driver continues to drill to the required depth for pile hole construction, the control device controls the hoisting mechanism (8) to stop lowering the extrusion and expansion drill bit. At the same time, the power head (6) continues to rotate and applies torque in the same direction as when the extrusion and expansion drill bit is drilled down, so that the extrusion and expansion drill bit rotates in situ, and the bottom soil thread that the cylindrical retaining body (2-1) has not reached is sheared. After the extrusion and expansion drill bit rotates for at least one circle, the control device controls the hoisting mechanism (8) to lift the power head (6) so that the extrusion and expansion drill bit moves upward until it reaches the ground surface; 4) into piles When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a concrete pile; Alternatively, after the extrusion and expansion drill tool is moved upward and lifted to the ground surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile; Alternatively, after the extrusion and expansion drill tool is moved upward and lifted to the ground surface, fillers are injected into the hole and the pile is expanded by tamping.

12. A method for forming piles by squeezing and expanding piles according to claim 11, characterized in that The extrusion and expansion drilling tool as claimed in claim 5 is fixed to the lower joint of the power head of the extrusion and expansion pile driver. When the bottom of the pile hole is a smooth hole during the construction of step 3), a reverse upper extrusion and expansion body (23) is coaxially connected between the extrusion and expansion body (2) and the connecting rod (3). During the upward lifting process, the extrusion and expansion drilling tool maintains the rotation direction when drilling down and continues to rotate. When the loose soil part of the pile hole side wall after extrusion and expansion falls off, the reverse blades (23-2-2) and the reverse Archimedean spiral surface (23-2-3) on the reverse upper extrusion and expansion body (23) radially squeeze the fallen soil into the pile hole side wall again, and the pile hole is shaped and held by the reverse cylindrical retaining body (23-1) and the cylindrical retaining body (2-1) until the extrusion and expansion drilling tool moves upward to the ground surface to form an extrusion and expansion pile smooth hole.

13. A method for forming piles by squeezing and expanding piles, characterized in that The steps of pile construction method include: 1) The pile extrusion machine is in place. The extrusion and expansion drilling tool as claimed in any one of claims 1 to 4 is fixed to the lower joint of the power head of the extrusion and expansion pile driver; 2) The front end of the soil is drilled synchronously to form a threaded hole in the soil, and the rear end of the soil thread is squeezed and expanded in situ to form a smooth hole. After the extrusion and expansion pile driver is installed in place, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) to start synchronous drilling, that is, every time the power head (6) rotates one circle, the hoisting mechanism (8) lowers the power head (6) and the extrusion and expansion drill tool downward by one lead for synchronous drilling. During the synchronous drilling process of the extrusion and expansion drill tool, the drill bit (1) of the extrusion and expansion drill tool drills the soil into a threaded hole. During the synchronous drilling process, the Archimedean spiral surface (2-2-3) on the special-shaped threaded extrusion and expansion body (2-2) of the extrusion and expansion drill tool, which is rotated downward in situ, gradually squeezes the thread formed on the soil into the side wall of the pile hole, and the cylindrical retaining body (2-1) on the special-shaped threaded extrusion and expansion body (2-2) continues to maintain the formed pile hole in compliance with the construction requirements. Repeat the above actions and drill synchronously until the designed depth of the pile hole is reached; 3) Synchronously withdraw the soil thread at the bottom and then lift the drill. After the drill is lifted, a threaded hole is formed at the bottom and a pile hole is squeezed and expanded at the top. When the pile driver continues to drill to the designed depth of the pile hole, the control device controls the power head (6) and the hoisting mechanism (8) to synchronously stop drilling downwards. At the same time, the control device simultaneously starts the power head (6) and the hoisting mechanism (8) in the reverse direction, so that each time the power head (6) rotates in the reverse direction, the hoisting mechanism (8) lifts the power head (6) and the extrusion and expansion drill tool up by one pitch, and after continuous operation, the extrusion and expansion drill tool synchronously exits the threaded section at the bottom, and is lifted to the ground surface after moving upwards and synchronously exiting the threaded section, so that a threaded extrusion and expansion pile hole is formed at the bottom of the pile hole, and an extrusion and expansion pile hole is formed at the top; 4) into piles, When the extrusion and expansion drill begins to lift upward, the concrete pump is started to pour concrete into the pile hole to the designed elevation to form a friction pile; Alternatively, after the extrusion and expansion drill moves upward and is lifted to the surface, a steel cage is lowered, a grouting pipe is injected, and grouting is performed to form a pile; Alternatively, when the extrusion and expansion drilling tool moves upward and is lifted to the surface, filler is poured into the hole and rammed to form a pile.

14. A method for forming piles by squeezing and expanding piles according to claim 13, characterized in that The extrusion and expansion drilling tool as claimed in claim 9 is fixed to the lower joint of the power head of the extrusion and expansion pile driver, and screw pile construction can be carried out.

15. A method for forming piles by squeezing and expanding piles according to claim 13 or 14, characterized in that A pile extrusion drilling tool as claimed in claim 6 is fixed to the lower joint of the power head of the pile extrusion and expansion machine. When returning the pile with the bottom of the pile hole being a threaded hole in step 3), the threaded section is gradually withdrawn during the reverse synchronous lifting process, and the pile extrusion and expansion drilling tool maintains the rotation direction of the withdrawn threaded section and continues to rotate. When the loose soil on the pile hole side wall above the same-direction extrusion and expansion body (22) falls off after being squeezed, the fallen soil is radially squeezed into the pile hole side wall again under the action of the same-direction blades (22-2-2) and the same-direction Archimedean spiral surface (22-2-3) on the same-direction extrusion and expansion body (22), and the pile hole is shaped and held by the same-direction cylindrical retaining body (22-1) and the cylindrical retaining body (2-1) until the pile extrusion and expansion drilling tool moves upward and is lifted to the ground surface to form a screw pile hole.

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