An ultra-deep bored pile construction system and method suitable for high-water-head soft foundation

Abstract

The invention discloses an ultra-deep bored pile construction system and method suitable for large-head soft foundation, the construction system comprises a soft base casing unit, a hoisting unit, an impact drill unit, a slurry changing unit and a protective tube unit, wherein the soft base casing unit is arranged in the soft base layer, the hoisting unit is arranged on the surface of the soft base layer outside the soft base casing unit, and is connected to the top of the impact drill unit, the impact drill unit is used to punch a hole in the soft base layer inside the soft base casing unit, the slurry changing unit extends into the punched hole, and the protective tube unit is cooperatively arranged in the punched hole; the invention solves the problems of poor verticality of the pile body of the bored pile and slurry leakage in the large-head seepage formation, and timely correction is achieved through the cooperation of the counterweight ring and the straightening assembly in the drill bit, thereby further ensuring the verticality of the borehole wall; the invention has good slag discharge capability, and improves the effective height of mud slag discharge through the follow-up segmented slag discharge method, thereby ensuring the efficiency and quality of mud slag discharge.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-deep bored pile construction, and in particular to an ultra-deep bored pile construction system and method suitable for large water head soft foundation. Background Art

[0002] As a highly efficient method for creating holes for pile foundations, bored piles utilize a percussion drill to raise a heavy drill bit (also known as a hammer) with a drill blade. The impact force of the drill bit, known as a hammer, cuts the rock layer, expelling debris to create a hole. As a relatively mature construction method, it has the following characteristics: 1) The impact method consumes little power and achieves excellent crushing results, especially for hard, cracked soil and large pebbles. 2) The impact of the soil creates a relatively strong hole wall, leading to its widespread use in soft soil areas such as coastal areas. 3) The construction equipment is simple and easy to operate.

[0003] In recent years, with the continuous development of my country's water conservancy projects, the construction depth of bored piles has gradually increased, and the construction environment has become more complex. As a result, the traditional bored pile construction technology can no longer meet the requirements of engineering construction. For bored pile construction in coastal areas, common engineering problems include the following: 1) Poor verticality of the pile body: When bored piles are constructed on soft soil foundations, the weight of the construction equipment will cause the soil around the construction equipment to deform, resulting in the casing tilting and reduced verticality of the borehole; 2) Serious mud leakage: When bored piles are constructed in permeable strata such as gravel layers and sand layers with large water heads, the mud used to balance the soil pressure tends to flow along the permeable strata, resulting in excessive mud consumption during the drilling process and pollution of the surrounding groundwater; 3) Poor verticality of the borehole wall: During the construction of bored piles, if large boulders are encountered, the drilled hole may deviate, and the punching hammer cannot correct the deviation; 4) Poor slag removal capacity: When the bored pile reaches a certain construction depth, the density difference between the upper and lower layers of the mud will become gradually obvious. As a result, the debris produced by the drilling cannot be completely removed by the mud, resulting in a large amount of sediment in the hole, which reduces the construction efficiency and hole quality of the bored pile.

[0004] Therefore, it is necessary to propose a device and a corresponding construction method for ultra-deep bored pile construction suitable for soft foundations with large water heads in coastal areas, which has the advantages of good pile verticality, high mud utilization rate, high verticality of the borehole wall and strong slag discharge capacity. Summary of the Invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0006] In view of the problems existing in the construction of ultra-deep bored piles for high-head soft foundations in coastal areas, such as poor pile verticality, serious mud leakage, poor verticality of the borehole wall and poor slag discharge capacity, the present invention is proposed.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: an ultra-deep bored pile construction system suitable for large water head soft foundation, this construction system includes a soft base casing unit, a hoisting unit, an impact drill unit, a slurry changing unit and a protective tube unit, wherein the soft base casing unit is arranged in the soft base layer, the hoisting unit is arranged on the surface of the soft base layer outside the soft base casing unit, and is connected to the top of the impact drill unit, and a hole is punched in the soft base layer inside the soft base casing unit by the impact drill unit, the slurry changing unit extends into the hole, and the protective tube unit is cooperatively arranged in the hole.

[0008] Furthermore, the soft base casing unit includes a flexible outer casing and a rigid inner casing, wherein the rigid inner casing is driven into the soft base layer inside the flexible outer casing; the top of the rigid inner casing is lower than the top height of the flexible outer casing.

[0009] Furthermore, the hoisting unit includes a hanger placed on the surface of the soft base layer between the flexible outer casing and the rigid inner casing, a drive motor arranged on the hanger, a rope frame connected to the output end of the drive motor, a rope wound on the rope frame, a pulley arranged on the rope, and a hook arranged at the lower end of the pulley; the end of the rope away from the rope frame is connected to the hanger.

[0010] Furthermore, the impact drill unit includes a drill bit, a connecting rod arranged in the middle of the top of the drill bit, a straightening assembly symmetrically arranged on the side wall of the connecting rod, and a correction assembly arranged on the top of the drill bit and located on the outside of the connecting rod; detachable drill teeth are also arranged on the bottom side wall of the drill bit; a lifting ring is provided on the top of the connecting rod, and the lifting hook is connected to the lifting ring.

[0011] Furthermore, the straightening assembly includes an arc-shaped touch plate, a support rod with one end connected to the inner ring side wall of the arc-shaped touch plate, and the other end of the support rod is connected to the side wall of the sleeve. The sleeve is sleeved on the fixing rod, and the end of the fixing rod is connected to the connecting rod; a plurality of groups of positioning holes are opened at equal intervals on the side wall of the fixing rod, and a through hole is opened on the sleeve, and the positioning pin can be fitted and inserted into the positioning hole and the through hole.

[0012] Furthermore, the deviation-correcting assembly includes a plurality of groups of vertical rods arranged at equal intervals and counterweight rings sleeved on the vertical rods.

[0013] Furthermore, the slurry changing unit includes a mud pool, a grouting pipe, a slurry extraction pipe and a sedimentation tank. One end of the grouting pipe is connected to the pump in the mud pool, and the other end extends to the bottom of the punching hole. The slurry extraction pipe is connected to the slurry extraction pump, one end of which extends into the punching hole, and the other end is placed in the sedimentation tank; the placement height of the slurry extraction pipe in the punching hole is greater than the placement height of the grouting pipe in the punching hole.

[0014] Furthermore, the protective cylinder unit includes a cylinder body, a hanging ring arranged on the top side wall of the cylinder body, and an adjustment rope arranged in the side wall of the cylinder body; the cylinder body has an opening, which is divided into a first end and a second end at the opening, the outer side wall of the first end has an outer hook, the inner side wall of the second end has an inner groove, and the outer hook can fit into the inner groove; the side wall of the second end has a connecting hole; one end of the adjusting rope is connected to the outer side wall of the first end close to the opening, and the other end passes through the connecting hole and extends above the cylinder body.

[0015] The present invention adopts the above-mentioned punching cast-in-place pile construction system to carry out the construction method, comprising the following construction steps:

[0016] S1: Determine the drill bit size, drill tooth type, and initial weighting of the drill bit according to planning requirements. After assembling the drilling equipment, place it in the area to be drilled.

[0017] S2: Drive a flexible outer casing outside the construction area to be drilled, and inject cement slurry into the bottom area of the inner ring of the flexible outer casing;

[0018] S3: Use a crane to drive the rigid inner casing into the soft base layer inside the flexible outer casing;

[0019] S4: Set up the hoisting unit, connect it to the lifting ring through the hook at the bottom, drive the impact drill unit to rise through the driving motor, and release the drill bit to impact the formation in the inner ring of the rigid inner casing to form a punch hole;

[0020] S5: Arrange a grouting pipe in the punching hole, with the grouting outlet of the grouting pipe located at the bottom of the punching hole, and continuously inject water into the punching hole;

[0021] S6: When the depth of the punching hole is greater than the length of the rigid inner casing, a slurry extraction pipe connected to a slurry extraction pump is arranged in the punching hole, and the slurry extraction port of the slurry extraction pipe is always located above the drill bit and in the mud layer;

[0022] S7: With the continuous injection of water into the grouting pipe and the continuous extraction of grout from the grouting pipe, the drill bit is cyclically lifted and released, impacting and punching the hole to the predetermined depth.

[0023] Furthermore, when a pebble layer and / or rock layer is encountered during the punching construction process, the protective tube unit is placed into the punching hole by a crane and driven into the pebble layer and / or rock layer area, and a straightening assembly is installed on the drill bit so that the drill bit passes vertically through the inner cavity of the cylinder and maintains vertical impact in the punching hole; when the center of the drill bit deviates during the punching construction process, the straightening assembly is adjusted and a counterweight ring is set on the top of the drill bit for adjustment; when the geological layer changes during the punching construction process, the drill bit is lifted out of the punching hole, and the drill teeth are replaced before continuing the punching construction.

[0024] Beneficial effects of the present invention:

[0025] 1) The problem of poor verticality of the pile body is solved. Through the combination of the rigid-flexible double casing and the surface anti-seepage reinforcement grouting technology, the horizontal stress of the pile driver on the soft soil layer during construction is reduced, effectively ensuring the overall verticality of the pile body;

[0026] 2) Solve the problem of mud leakage in high-head seepage formations. Through surface anti-seepage reinforcement grouting technology, an impermeable layer is formed on the outer ring of the rigid inner casing to prevent mud from flowing out of the permeable formation, saving mud and protecting the environment.

[0027] 3) Ensures the verticality of the borehole wall. During the impact drilling process, the verticality of the borehole wall is guaranteed from the perspective of mechanics and physics through the real-time adjustment of the drill center (counterweight ring) and the combined operation of the lateral restraint (straightening assembly). If any deviation occurs, the deviation is corrected in real time.

[0028] 4) The mud deslagging ability in deep drilling is guaranteed. The effective height of mud deslagging is increased through the follow-up segmented deslagging method, ensuring the mud deslagging efficiency and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0030] Figure 1 The figure is a schematic diagram of the overall structure of the ultra-deep bored pile construction system suitable for large water head soft foundation according to the present invention.

[0031] Figure 2 It is a partially enlarged structural schematic diagram of the ultra-deep bored pile construction system applicable to soft foundation with large water head according to the present invention.

[0032] Figure 3 The figure is a schematic structural diagram of the hoisting unit of the ultra-deep bored pile construction system suitable for large water head soft foundation according to the present invention.

[0033] Figure 4 The diagram is a schematic diagram of the overall structure of the impact drill unit of the ultra-deep bored pile construction system suitable for large water head soft foundation according to the present invention.

[0034] Figure 5 The figure is a schematic diagram of the specific structure of the impact drill unit of the ultra-deep bored pile construction system suitable for large water head soft foundation of the present invention.

[0035] Figure 6 This is a schematic diagram of the overall structure of the protective tube unit of the ultra-deep bored pile construction system suitable for large water head soft foundations of the present invention.

[0036] Figure 7 The diagram is a schematic diagram of the contraction and expansion states of the cylinder in the protective cylinder unit of the ultra-deep bored pile construction system suitable for large water head soft foundation of the present invention. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0040] Furthermore, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, when describing the embodiments of the present invention, cross-sectional views illustrating device structures may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, the three-dimensional dimensions of length, width, and depth should be included.

[0041] Example 1

[0042] Reference Figures 1 to 7, which is the first embodiment of the present invention, provides an ultra-deep bored pile construction system suitable for large water head soft foundation, this construction system includes a soft base casing unit 10, a hoisting unit 20, an impact drill unit 30, a slurry changing unit 40 and a protective tube unit 50, wherein the soft base casing unit 10 is arranged in the soft base layer to reduce the deformation problem of the soft base layer caused by the parking construction of heavy equipment; the hoisting unit 20 is arranged on the surface of the soft base layer outside the soft base casing unit 10, and is connected to the top of the impact drill unit 30. The impact drill unit 30 is used to punch a punching hole C in the soft base layer inside the soft base casing unit 10, and the slurry changing unit 40 extends into the punching hole C, and is used to grout at the bottom of the punching hole C and extract the generated mud slurry; the protective tube unit 50 is cooperatively arranged in the punching hole C to improve the adaptability of the impact drill unit 30.

[0043] Specifically, combined with Figure 2 The soft base casing unit 10 includes a flexible outer casing 11 and a rigid inner casing 12. The rigid inner casing 12 is driven into the soft base layer inside the flexible outer casing 11; the top of the rigid inner casing 12 is lower than the top height of the flexible outer casing 11. The flexible outer casing 11 can be made of flexible or rigid materials and has a large diameter. It can circle the area to be punched and constructed. Construction machinery is parked in the outer ring area of the flexible outer casing 11. The flexible outer casing 11 reduces the deformation of the soft base layer in the punching area caused by the pressure of heavy equipment. The inner ring of the rigid inner casing 12 is the formation area of the punching hole C, which is driven into the inner ring area of the flexible outer casing 11. It should be noted that the rigid inner casing 12 is made of hard rigid material, and the height of its cylinder is greater than the cylinder height of the flexible outer casing 11, but the depth of the rigid inner casing 12 driven into the soft base layer is greater than the depth of the flexible outer casing 11 driven into the soft base layer. Finally, the top height of the rigid inner casing 12 after burial is greater than the bottom height of the flexible outer casing 11 after burial, so that there is an annular area with an intersection between the two. Cement slurry is injected into this annular area, which is used to improve the strength of the top of the punching hole C, and also to prevent the mud generated by the punching construction from seeping into the formation, causing leakage and running of slurry, and polluting the surrounding groundwater.

[0044] Furthermore, combined with Figure 3 The hoisting unit 20 includes a hanger 21 placed on the soft base surface between the flexible outer casing 11 and the rigid inner casing 12, a driving motor 22 arranged on the hanger 21, a rope frame 23 connected to the output end of the driving motor 22, a rope 24 wound on the rope frame 23, a pulley 25 arranged on the rope 24, and a hook 26 arranged at the lower end of the pulley 25; the end of the rope 24 away from the rope frame 23 is connected to the hanger 21.

[0045] Specifically, the hoisting unit 20 is used to hoist the impact drill unit 30, and is entirely arranged at the working end of the crane. The hanger 21 is used to install various components. The drive motor 22 drives the winch in the rope frame 23 to rotate, and drives the pulley 25 to rise and fall through the rope 24. The pulley 25 is hung on the impact drill unit 30 through the hook 26 at the lower end. The function of the pulley 25 is to enable the drive motor 22 to adapt to larger and heavier impact drills, thereby improving applicability.

[0046] Combined with attachment Figure 4 and 5 As shown in the figure, the impact drill unit 30 includes a drill bit 31, a connecting rod 32 arranged in the middle of the top of the drill bit 31, a straightening assembly 33 symmetrically arranged on the side wall of the connecting rod 32, and a correction assembly 34 arranged on the top of the drill bit 31 and located on the outside of the connecting rod 32; a detachable drill tooth 31a is also provided on the bottom side wall of the drill bit 31; a lifting ring 32a is provided on the top of the connecting rod 32, and a lifting hook 26 is connected to the lifting ring 32a.

[0047] The straightening assembly 33 includes an arc-shaped touch plate 33a, a support rod 33b with one end connected to the inner ring side wall of the arc-shaped touch plate 33a, and the other end of the support rod 33b is connected to the side wall of the sleeve 33c. The sleeve 33c is sleeved on the fixing rod 33d, and the end of the fixing rod 33d is connected to the connecting rod 32; a plurality of groups of positioning holes D are opened at equal intervals on the side wall of the fixing rod 33d, and a through hole T is opened on the sleeve 33c, and the positioning pin X can be inserted into the positioning hole D and the through hole T.

[0048] The deviation-correcting assembly 34 includes a plurality of vertical rods 34 a arranged at equal intervals and a counterweight ring 34 b sleeved on the vertical rods 34 a.

[0049] Furthermore, the drill bit 31 is the drill body part of the impact drill unit 30, and has a drill tooth 31a at the bottom thereof, which impacts the stratum or stone layer to form a drill hole. It is installed at the bottom of the drill bit 31 using a detachable structure, and the drill tooth 31a is replaced according to different strata. The detachable structure can select commonly used structures on the market, such as threaded connection, pin connection, and snap connection. The connecting rod 32 at the top of the drill bit 31 is used for hanging the drill body and installing the straightening assembly 33. The straightening assembly 33 is used to adjust the contact between the drill bit 31 and the punching hole C, and is used to help the drill bit 31 straighten its posture and impact to form a punching hole C with high verticality. Specifically, the straightening assembly 33 is connected to the side wall of the connecting rod 32 located at the top of the drill bit 31, wherein the support length of the arc touch plate 33a is determined by the position of the sleeve 33c sleeved on the fixed rod 33d, and the sleeve 33c can be positioned and sleeved at any position on the fixed rod 33d through the positioning pin X.

[0050] The correction component 34 is used to change the overall center of gravity of the drill bit 31. This is achieved by configuring a counterweight ring 34b with different gravity on the top side wall of the drill bit 31, thereby changing the falling posture of the drill bit 31 in the punching hole C and adjusting the forming quality of the punching hole C.

[0051] For the pulp changing unit 40, Figure 1 and 2 As shown in , it includes a mud pit 41, a grouting pipe 42, a slurry extraction pipe 43, and a sedimentation tank 44. One end of the grouting pipe 42 is connected to the pump in the mud pit 41, and the other end extends to the bottom of the punch hole C. The slurry extraction pipe 43 is connected to the slurry extraction pump, with one end extending into the punch hole C and the other end placed in the sedimentation tank 44. The placement height of the slurry extraction pipe 43 in the punch hole C is greater than the placement height of the grouting pipe 42 in the punch hole C. The grouting pipe 42 is used to inject water or diluted mud liquid into the bottom of the punch hole C, which is used to lubricate the drill bit 31 and dilute the soil generated by the drill bit 31 impacting the soft base layer to form mud. The nozzle of the slurry extraction pipe 43 needs to be below the mud liquid level. It should be noted that the lifting height of the drill bit 31 should be lower than the nozzle height of the slurry extraction pipe 43. Therefore, without affecting the operation of the drill bit 31, the grouting pipe 42 can be a soft pipe, while the slurry extraction pipe 43 needs to be a hard pipe.

[0052] Furthermore, combined with Figure 6 and 7 The protective cylinder unit 50 includes a cylinder body 51, a hanging ring 52 arranged on the top side wall of the cylinder body 51, and an adjusting rope 53 arranged in the side wall of the cylinder body 51; the cylinder body 51 has an opening K, and is divided into a first end D1 and a second end D2 at the opening K, an outer hook 51a is provided on the outer wall of the first end D1, and an inner groove 51b is provided on the inner wall of the second end D2, and the outer hook 51a can be fitted into the inner groove 51b; a connecting hole L is provided in the side wall of the second end D2; one end of the adjusting rope 53 is connected to the outer wall of the first end D1 near the opening K, and the other end passes through the connecting hole L and extends above the cylinder body 51. Among them, the hanging ring 52 is used for lifting the cylinder 51 as a whole, and the setting of the opening K is used to adjust the diameter of the cylinder 51. The adjusting rope 53 passes through the connecting hole L and is connected to the side wall of the first end D1, which can tighten the opening K and reduce the diameter of the cylinder 51. In the natural state, under the action of its own elastic force, the outer hook 51a of the cylinder 51 can fit in the inner groove 51b, so that the opening K disappears and the cylinder 51 is at the maximum diameter; the adjusting rope 53 is controlled by an external lifting device.

[0053] Example 2

[0054] Reference Figures 1 to 7 , which is the second embodiment of the present invention. This embodiment differs from the first embodiment in that: this embodiment is a method for construction using the punching and grouting pile construction system of the above-mentioned embodiment 1, comprising the following construction steps:

[0055] S1: According to planning requirements, determine the size of the drill bit 31, the type of drill teeth 31a, and perform initial weighting on the drill bit 31. After the drilling equipment is assembled, it is placed in the area to be drilled;

[0056] Specifically, the drilling area for the cast-in-place pile must be designed and planned in advance. The size and weight of the drill bit 31 to be used are determined based on the planned requirements. Different types of drill teeth 31a are prepared based on the detected stratum distribution. The equipment required for the drilling construction is transported to the area to be drilled. It can be assembled on-site or transported to the construction site after assembly.

[0057] S2: driving a flexible outer casing 11 outside the construction area to be drilled, and injecting cement slurry into the inner ring bottom area of the flexible outer casing 11;

[0058] S3: Using a crane, the rigid inner casing 12 is driven into the soft base layer in the inner area of the flexible outer casing 11;

[0059] Before drilling, the ground in the drilling area needs to be reinforced. That is, a flexible outer casing 11 is first driven into the periphery of the drilling location. Large equipment such as hoisting construction is parked on the outer ring of the flexible outer casing 11. Then, a rigid inner casing 12 is driven into the inner ring area of the flexible outer casing 11. Under the protection of the flexible outer casing 11, the verticality of the rigid inner casing 12 is guaranteed. Furthermore, cement slurry is poured into the annular area between the inner and flexible outer casings to prevent infiltration in the annular areas of the two, forming a leak-proof slurry layer to prevent the mud discharged during the punching construction from seeping into the underground layer and polluting the surrounding groundwater.

[0060] S4: The hoisting unit 20 is set up and connected to the lifting ring 32a via the hook 26 at the bottom. The impact drill unit 30 is driven by the driving motor 22 to be lifted. The drill bit 31 is released to impact the ground in the inner ring of the rigid inner casing 12 to form a punch hole C.

[0061] S5: Arrange a grouting pipe 42 in the punching hole C, with the grouting outlet of the grouting pipe 42 located at the bottom of the punching hole C, and continuously inject water into the punching hole C;

[0062] Then, the hoisting unit 20 is prepared, the hook 26 is hung on the lifting ring 32a at the top of the drill bit 31, and the impact drill unit 30 is driven to rise by the driving motor 22. When it rises to a certain height, the drill bit 31 is released, so that it impacts the stratum in the inner ring of the rigid inner casing 12 under the action of gravity to form a punching hole C. During the impact, water or low-concentration cement slurry is injected through the grouting pipe 42 at the punching hole position formed, which not only ensures the smoothness of the drill bit 31 during the punching process, but also enables the soil and mortar in the stratum to be dispersed and diluted to form slurry, which is then extracted out of the punching hole C by the slurry extraction pipe 43.

[0063] S6: When the depth of the punching hole C is greater than the length of the rigid inner casing 12, a slurry extraction pipe 43 connected to a slurry extraction pump is arranged in the punching hole C, and the slurry extraction port of the slurry extraction pipe 43 is ensured to be always located above the drill bit 31 and within the mud layer;

[0064] S7: With the continuous injection of water into the grouting pipe 42 and the continuous extraction of grout from the extraction pipe 43, the drill bit 31 is cyclically lifted and released, striking and punching the hole C to a predetermined depth.

[0065] As construction continues, the depth of the punching hole C gradually exceeds the depth of the rigid inner casing 12, and a slurry pump is connected to the slurry pumping pipe 42 to ensure sufficient suction force. It should be noted that when the depth of the punching hole C is large enough, the mud layer formed by the punching water injection will cover the lifting height of the drill bit 31, so that the drill bit 31 always operates in the mud layer, and the suction port of the slurry pumping pipe 42 is always located below the liquid level of the mud layer, but always above the drill bit 31.

[0066] Furthermore, when a pebble layer and / or rock layer is encountered during the construction of the punching hole C, the protective tube unit 50 is placed into the punching hole C by a crane and driven into the pebble layer and / or rock layer area, and a straightening assembly 33 is installed on the drill bit 31 so that the drill bit 31 vertically passes through the inner cavity of the cylinder 51 and remains vertically impacting in the punching hole C; specifically, when encountering a pebble or a large rock formation, the hoisting unit 20 needs to be lifted out of the punching hole C, and then the protective tube unit 50 is placed into the hole by a crane. During the process of placing the cylinder 51, the opening K needs to be contracted by the adjusting rope 53 so that the cylinder 51 The radial diameter is smaller than the aperture of the punching hole C, which is convenient for the insertion of the cylinder 51. When it is placed in the predetermined position, the adjusting rope 53 is loosened, and under the action of the opening tension of the cylinder 51, it is restored to the original cylinder diameter, and then it can be attached to the inner wall of the punching hole C. The cylinder 51 is driven into the pebble layer or stone formation area by pressure equipment or by impacting with the drill bit 31 to protect the side wall of the punching hole C and keep the drill bit 31 smooth during the falling impact process. After adding the protection of the cylinder 51, the position of the arc touch plate 33a in the straightening assembly 33 needs to be adjusted so that it can adapt to the inner diameter of the cylinder 51.

[0067] When the center of the drill bit 31 deviates during the construction of the punching hole C, the straightening assembly 33 is adjusted, and a counterweight ring 34b is set on the top of the drill bit 31 for adjustment; specifically, during the punching construction process, if the drill bit 31 is blocked by rocks or other hard obstacles, the drill bit 31 will deviate. In such a case, the straightening assembly 33 can be adjusted, and the positions of the arc-shaped touch plates 33a on both sides are adjusted so that the drill bit 31 can generate stress opposite to the deflection direction, and by configuring counterweight rings 34b of different sizes at different positions on the top side wall of the drill bit 31, the center of gravity of the drill bit 31 is changed, thereby maintaining the verticality of the subsequent punching hole C.

[0068] If the geological strata change during the drilling process, the drill bit 31 is lifted out of the drilling hole C, the drill teeth 31a are replaced, and the drilling process can be continued. Furthermore, to adapt to different geological strata, different types of drill teeth 31a can be replaced at the bottom of the drill bit 31. When replacing the drill teeth 31a, the drill bit 31 needs to be lifted out of the drilling hole C and replaced using the corresponding replacement tool.

[0069] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An ultra-deep bored pile construction system suitable for high-water-head soft foundation, characterized by: include, soft A base casing unit (10), a hoisting unit (20), an impact drill unit (30), a slurry changing unit (40) and a protective tube unit (50), wherein the soft base casing unit (10) is arranged in a soft base layer, the hoisting unit (20) is arranged on the ground of the soft base layer outside the soft base casing unit (10), and is connected to the top of the impact drill unit (30), and a punching hole (C) is punched in the soft base layer inside the soft base casing unit (10) by the impact drill unit (30), the slurry changing unit (40) extends into the punching hole (C), and the protective tube unit (50) is cooperatively arranged in the punching hole (C); The soft base casing unit (10) comprises a flexible outer casing (11) and a rigid inner casing (12), wherein the rigid inner casing (12) is driven into the soft base layer inside the flexible outer casing (11); The impact drill unit (30) comprises a drill bit (31), a connecting rod (32) arranged at the middle of the top end of the drill bit (31), a straightening assembly (33) symmetrically arranged on the side wall of the connecting rod (32), and a deviation correction assembly (34) arranged at the top of the drill bit (31) and located outside the connecting rod (32); The bottom side wall of the drill bit (31) is also provided with detachable drill teeth (31a); A lifting ring (32a) is provided on the top of the connecting rod (32), and a lifting hook (26) is connected to the lifting ring (32a); The straightening assembly (33) comprises an arc-shaped touch plate (33a), a support rod (33b) one end of which is connected to the inner ring side wall of the arc-shaped touch plate (33a), the other end of the support rod (33b) is connected to the side wall of a sleeve (33c), the sleeve (33c) is sleeved on a fixing rod (33d), and the end of the fixing rod (33d) is vertically connected to the side wall of the connecting rod (32); A plurality of groups of positioning holes (D) are provided at equal intervals on the side wall of the fixing rod (33d), a through hole (T) is provided on the sleeve (33c), and a positioning pin (X) can be inserted into the positioning hole (D) and the through hole (T); The deviation-correcting assembly (34) comprises a plurality of groups of vertical rods (34a) arranged at equal intervals and a counterweight ring (34b) sleeved on the vertical rods (34a); The protective cylinder unit (50) comprises a cylinder (51), a hanging ring (52) arranged on the top side wall of the cylinder (51), and an adjustment rope (53) arranged in the side wall of the cylinder (51); The cylinder (51) has an opening (K) and is divided into a first end (D1) and a second end (D2) at the opening (K); an outer hook (51a) is provided on the outer side wall of the end of the first end (D1); an inner groove (51b) is provided on the inner side wall of the end of the second end (D2); the outer hook (51a) can be fitted and connected in the inner groove (51b); a connecting hole (L) is provided in the side wall of the second end (D2); One end of the adjustment rope (53) is connected to the outer wall of the first end (D1) away from the opening (K), and the other end passes through the connecting hole (L) and extends above the cylinder (51).

2. The ultra-deep bored pile construction system suitable for high water head soft foundation according to claim 1 is characterized by: The top of the rigid inner casing (12) is lower than the top height of the flexible outer casing (11).

3. The ultra-deep bored pile construction system suitable for high water head soft foundation according to claim 2 is characterized by: The hoisting unit (20) includes a hanger (21) placed on the soft ground surface between the flexible outer casing (11) and the rigid inner casing (12), a driving motor (22) arranged on the hanger (21), a rope frame (23) connected to the output end of the driving motor (22), a rope (24) wound around the rope frame (23), a pulley (25) arranged on the rope (24), and a hook (26) arranged at the lower end of the pulley (25); One end of the suspension rope (24) away from the rope frame (23) is connected to the suspension frame (21).

4. The ultra-deep bored pile construction system suitable for high water head soft foundation according to any one of claims 1 to 3, characterized in that: The slurry replacement unit (40) includes a slurry pool (41), a grouting pipe (42), a slurry extraction pipe (43) and a sedimentation tank (44); one end of the grouting pipe (42) is connected to the slurry pool (41) through a pump, and the other end extends to the bottom of the punching hole (C); the slurry extraction pipe (43) is connected to the slurry extraction pump, one end of which extends into the punching hole (C), and the other end is placed in the sedimentation tank (44); The placement height of the grouting pipe (43) in the punching hole (C) is greater than the placement height of the grouting pipe (42) in the punching hole (C).

5. A method for constructing an ultra-deep bored pile system suitable for high-water-head soft foundations, characterized by: The method comprises the ultra-deep bored pile construction system applicable to a soft foundation with a large water head as claimed in any one of claims 1 to 4, and further comprises the following construction steps: S1: According to planning requirements, determine the size of the drill bit (31), the type of the drill teeth (31a), and perform initial weighting on the drill bit (31), assemble the drilling equipment, and arrange it in the area to be drilled; S2: driving a flexible outer casing (11) outside the construction area to be drilled, and injecting cement slurry into the inner ring bottom area of the flexible outer casing (11); S3: driving the rigid inner casing (12) into the soft base layer in the inner area of the flexible outer casing (11) by a crane; S4: erecting the hoisting unit (20), connecting it to the hoisting ring (32a) via the bottom hook (26), driving the impact drill unit (30) to be lifted by the driving motor (22), and releasing the drill bit (31) to impact the ground in the inner ring of the rigid inner casing (12) to form a punch hole (C); S5: arranging a grouting pipe (42) in the punching hole (C), wherein the grouting outlet of the grouting pipe (42) is located at the bottom of the punching hole (C), and continuously injecting water into the punching hole (C); S6: When the depth of the punching hole (C) is greater than the length of the rigid inner casing (12), a slurry extraction pipe (43) connected to a slurry extraction pump is arranged in the punching hole (C), and the slurry extraction port of the slurry extraction pipe (43) is always located above the drill bit (31) and in the mud layer; S7: With the continuous injection of water into the grouting pipe (42) and the continuous extraction of grout from the extraction pipe (43), the drill bit (31) is cyclically lifted and released, impacting and punching the hole (C) to a predetermined depth.

6. The method for constructing an ultra-deep bored pile system suitable for high-water-head soft foundation according to claim 5, characterized in that: When a pebble layer and / or rock layer is encountered during the punching hole (C), the protective cylinder unit (50) is placed into the punching hole (C) by a crane and driven into the pebble layer and / or rock layer area, and a straightening assembly (33) is installed on the drill bit (31) so that the drill bit (31) vertically passes through the inner cavity of the cylinder (51) and remains vertically impacting in the punching hole (C); When the center of the drill bit (31) deviates during the punching (C) construction process, the centering assembly (33) is adjusted, and a counterweight ring (34b) is set on the top of the drill bit (31) for adjustment; When a geological layer change occurs during the punching hole (C), the drill bit (31) is lifted out of the punching hole (C), and the drill teeth (31a) are replaced before continuing the punching construction.

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