Hydraulic drilling system for pipe pile while drilling and construction method

Abstract

The invention discloses a hydraulic drilling system for a while-drilling pipe pile and a construction method. The hydraulic drilling system comprises a pipe pile, a spiral drilling rod, a jetting and sucking pipe and a drill bit. The spiral drill rod is rotationally mounted in the pipe pile, and one end of the spiral drill rod penetrates through the pipe pile and is sequentially connected with the injection and suction pipe and the drill bit; the spiral drill rod is of a hollow structure, and the top end is connected with a slurry pump for inputting clear water. The injection-suction pipe is communicated with the spiral drill rod and the drill bit; an injection and suction cavity is formed in the injection and suction pipe, and a suction inlet is formed in the injection and suction cavity; when the jetting and sucking pipe conveys clean water, the jetting and sucking cavity can form a negative pressure cavity so that broken particles formed in the drilling process can be sucked through the suction inlet, and the broken particles and the clean water can form abrasive water jet. The drill bit has a nozzle assembly. By means of the arrangement, the functions of efficiently cooling the drill bit and assisting rock breaking and chip removal can be achieved only by inputting clear water, and the purposes of improving the hard rock drilling efficiency, prolonging the service life of equipment, simplifying a construction system and being environmentally friendly and free of pollution are achieved.

Description

Technical Field

[0001] The present invention relates to the field of pipe piles with following drill pipes, and particularly to a hydraulic drilling system and construction method for pipe piles with following drill pipes. Background Art

[0002] The technology of pipe piles with following drill pipes is widely used in infrastructure construction. The existing drilling methods for pipe piles with following drill pipes are mainly dry drilling methods, and the bit life, drilling efficiency and pile forming quality in hard rock formations are not ideal. During drilling, the circulating flushing fluid can cool the bit, carry rock cuttings, assist in rock breaking and maintain the stability of the hole wall. Traditional hydraulic drilling systems mainly use mud or clear water as the flushing fluid, but there are certain deficiencies when both are used as flushing fluids.

[0003] When using mud as the flushing fluid, although its high viscosity can effectively carry rock cuttings and cool the bit through fluid circulation, it requires an expensive and bulky solids control system to control the solid particle content in the mud and the flow performance of the mud, which will increase the construction equipment cost. Moreover, during the construction of pipe piles with following drill pipes, the construction equipment will move frequently with the hole position, and the movement of the bulky solids control equipment is very difficult, resulting in very inconvenient operation. In addition, when using mud, additives need to be added to ensure the flow performance of the mud, so the additives in the mud will also pollute the formation, which does not meet the requirements of environmental protection construction.

[0004] When using clear water as the flushing fluid, although it has the advantages of low cost and environmental friendliness, it has the defect of insufficient chip carrying capacity due to its low viscosity. Especially in the working condition where the annular clearance at the bottom of the pipe pile with following drill pipes is large, the upward flow velocity of the flushing fluid is slow, and large particle rock cuttings are easily deposited at the bottom of the hole, resulting in repeated bit breaking, increased energy consumption, and the chip cushion layer will reduce the bonding strength between the pipe pile and the formation, affecting the bearing performance. If the flow rate of clear water is increased to improve the chip carrying capacity, it will cause the bottom hole pressure to rise, resulting in leakage of the flushing fluid and erosion of the hole wall, damaging the side friction resistance of the pipe pile. In addition, the density of clear water is small, and the hole wall protection performance is poor.

[0005] Therefore, a hydraulic drilling system and construction method for pipe piles with following drill pipes are needed to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a hydraulic drilling system and construction method for pipe piles with following drill pipes, so that only by inputting clear water, the functions of efficient cooling of the bit and assisting in rock breaking and chip removal can be realized, achieving the purposes of improving the hard rock drilling efficiency, extending the equipment life, simplifying the construction system and being environmentally friendly and pollution-free.

[0007] To solve the above technical problems, the present invention provides a hydraulic drilling system for pipe piles with following drill pipes, including a pipe pile, a spiral drill rod, a jet suction pipe and a bit; The auger rod is rotatably installed inside the pipe pile, and one end of the auger rod passes through the pipe pile and is successively connected to the jet suction pipe and the drill bit; Wherein, the auger rod and the pipe pile can move synchronously in a direction perpendicular to the construction surface, and the auger rod is of a hollow structure, and a slurry pump for inputting clear water is connected to the opening at the top end; The jet suction pipe is communicated with the auger rod and the drill bit for the transmission of clear water; Wherein, a jet suction cavity is formed inside the jet suction pipe, and a suction port communicated with the external environment is arranged on the jet suction cavity; When clear water flows through the jet suction pipe, the jet suction cavity can form a negative pressure chamber to suck the broken particles formed during the drilling process through the suction port, so that the broken particles are mixed with the clear water to form an abrasive water jet; The drill bit has a nozzle assembly for jetting clear water and the abrasive water jet.

[0008] Further, the jet suction pipe includes a pipe body, a jet nozzle and a throat pipe; Both ends of the pipe body are detachably and hermetically connected to the auger rod and the drill bit respectively; The jet nozzle and the throat pipe are sequentially arranged in the pipe body from the direction away from the auger rod, and a gap is reserved between the output end of the jet nozzle and the throat pipe, so that a jet suction cavity capable of forming a negative pressure chamber is formed among the jet nozzle, the pipe body and the throat pipe.

[0009] Further, the drill bit includes a cavity, an underreaming pick plate and a bottom pick plate; The underreaming pick plate is rotatably installed on the outer wall of the cavity and has a closed state and an expanded state; Wherein, the closed state and the expanded state are switched by the rotation direction of the auger rod and the reaction force received by the underreaming pick plate when contacting the formation; And when the underreaming pick plate is in the closed state, the outer diameter of the drill bit is smaller than the inner diameter of the pipe pile; The bottom pick plate is fixedly installed at the bottom of the cavity.

[0010] Further, a first flow channel and a jet nozzle communicated with the first flow channel are built in the underreaming pick plate; An installation seat for installing the underreaming pick plate is formed on the outer side of the cavity, and a second flow channel and a third flow channel which are communicated with each other are respectively arranged on the cavity and the installation seat; When the underreaming pick plate is in the expanded state, the first flow channel, the second flow channel and the third flow channel are sequentially communicated; When the reaming pick plate is in the closed state, the third flow channel is disconnected from the first flow channel, and the outlet of the third flow channel just faces the rotating shaft of the reaming pick plate.

[0011] Furthermore, a plurality of the reaming pick plates are provided, and the plurality of reaming pick plates are arranged in a circular array centered on the axis of the cavity.

[0012] Furthermore, the nozzle assembly includes a first radial nozzle and a second radial nozzle disposed in the cavity; The opening direction of the first radial nozzle faces the rotational connection between the corresponding reaming pick plate and the cavity; The opening direction of the second radial nozzle faces the direction to be worked when the corresponding reaming pick plate performs reaming operation; Wherein, when the reaming pick plate is in the closed state, the opening of the second radial nozzle faces the corresponding reaming pick plate; The inner diameter of the first radial nozzle increases along the output direction, and the inner diameter of the second radial nozzle decreases along the output direction.

[0013] Furthermore, the nozzle assembly further includes an axial nozzle disposed in the cavity for assisting the bottom pick plate in performing drilling operation.

[0014] Furthermore, a sand removal cylinder is further included; The sand removal cylinder is detachably and fixedly installed on the outer wall of the end of the pipe pile, and the auger can convey the mixed liquid formed during the drilling process along the inner wall of the pipe pile into the sand removal cylinder; A recovery port for recovering clear water in the mixed liquid is provided on one side of the top end of the sand removal cylinder, and the mud pump is connected to the recovery port and the top opening of the auger through a pipeline for recycling clear water; The inner cavity bottom wall of the sand removal cylinder has an annular sand and gravel cavity for collecting broken particles in the mixed liquid, and a sand discharge port is provided on one side of the annular sand and gravel cavity; The inner wall of the sand removal cylinder is also fixedly installed with spiral blades arranged in the opposite direction to the blades on the auger for accelerating the separation and deposition of broken particles in the mixed liquid.

[0015] Furthermore, the hydraulic drilling system further includes a drilling rig and a mud pit connected to the auger; Both the mud pit and the mud pump are fixed on the drilling rig, and the mud pit is communicated with the recovery port; The mud pump is used to output the clear water input into the mud pit to the top opening of the auger.

[0016] On the other hand, the present invention also provides a construction method for the pipe - following pile while drilling, which is realized by using the hydraulic drilling system for the pipe - following pile while drilling described in the above - mentioned embodiment, and specifically includes the following steps: S1. Insert the auger rod into the bottom of the pipe pile; S2. Control the auger rod to rotate in a predetermined direction, driving the drill bit to run synchronously to drill into the formation; S3. Clear water is output by the mud pump and enters the suction chamber of the jet - suction pipe through the hollow cavity of the auger rod. Under the high - pressure impact of the clear water, a negative - pressure chamber is formed in the suction chamber of the jet - suction pipe, so as to suck in real - time the broken particles formed during the drilling process through the suction port, making the broken particles mix with the clear water to form an abrasive water jet, and the abrasive water jet is ejected from the nozzle assembly of the drill bit to assist the drill bit in rock breaking; S4. Control the pipe pile to move downward along the direction perpendicular to the construction surface following the auger rod; S5. When the pipe pile sinks to the preset depth, lift the auger rod, the jet - suction pipe and the drill bit from the bottom of the middle hole of the pipe pile.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: By providing a jet - suction pipe with a suction chamber formed inside and a suction port, and connecting it with the hollow - structured auger rod and the drill bit with a nozzle assembly, when clear water is input into the auger rod, the negative - pressure entrainment effect of the suction chamber can be used to automatically suck in the broken particles formed during the drilling process, and the broken particles can be mixed with the clear water to form an abrasive water jet and ejected from the nozzle assembly of the drill bit, so as to enhance the rock - breaking ability of the drill bit by means of the characteristics of the abrasive water jet, that is, to complete the enhancement of the rock - breaking ability. And, due to the jet - entrainment effect of the jet - suction pipe, a local circulating flow field can be formed at the bottom of the hole, and further, the upward return velocity of the mixed liquid formed by the broken particles and the clear water can be increased, achieving the purpose of preventing cuttings from depositing and enhancing the chip - carrying effect of the clear water. In addition, through the clear - water input and the negative - pressure chip - sucking mechanism of the jet - suction pipe, the application of mud as a cleaning liquid in the prior art is replaced, so that the mud pump does not directly contact the particles in the mud during the whole process, thereby avoiding the wear of the mud pump, achieving the purpose of improving the durability of the equipment, simplifying the construction equipment and eliminating the risk of mud pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the hydraulic drilling system for the pipe - following pile while drilling in an embodiment of the present invention; Figure 2 For the present invention Figure 1 is a partial structural diagram at the drill bit; Figure 3 is a sectional view of the jet - suction pipe in the hydraulic drilling system for the pipe - following pile while drilling in an embodiment of the present invention; Figure 4The top view cross-sectional view of the reaming pick plate in the hydraulic drilling system for the pipe pile while drilling Figure 5 The top view cross-sectional view of the reaming pick plate in the hydraulic drilling system for the pipe pile while drilling in a closed state according to an embodiment of the present invention; Figure 6 The cross-sectional view of the drill bit in the hydraulic drilling system for the pipe pile while drilling according to another embodiment of the present invention; Figure 7 The top view cross-sectional view of the reaming pick plate in the hydraulic drilling system for the pipe pile while drilling in a closed state according to another embodiment of the present invention; Figure 8 The top view cross-sectional view of the reaming pick plate in the hydraulic drilling system for the pipe pile while drilling in an expanded state according to another embodiment of the present invention.

[0019] Reference numerals in the drawings: 1. Pipe pile; 2. Auger drill rod; 3. Jet suction pipe; 31. Pipe body; 32. Jet nozzle; 33. Throat pipe; 4. Drill bit; 41. Cavity; 411. Second flow channel; 412. Third flow channel; 42. Reaming pick plate; 421. First flow channel; 422. Jet nozzle; 43. Bottom pick plate; 5. Jet suction cavity; 51. Suction port; 6. Nozzle assembly; 61. First radial nozzle; 62. Second radial nozzle; 63. Axial nozzle; 7. Sand removal cylinder; 71. Recovery port; 72. Annular sand and gravel cavity; 721. Sand discharge port; 73. Helical blade; 8. Drilling rig; 81. Mud pump; 82. Mud pit. Detailed implementation manners

[0020] The hydraulic drilling system and construction method for the pipe pile while drilling of the present invention will be described in more detail below with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present invention.

[0021] In the following paragraphs, the present invention will be described more specifically by way of example with reference to the drawings. The advantages and features of the present invention will be clearer according to the following description. It should be noted that the drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0022] Embodiment 1 As Figures 1 to 3As shown in the figure, an embodiment of the present invention provides a hydraulic drilling system for follow - up pipe piles during drilling, which includes a pipe pile 1, a spiral drill rod 2, a jet - suction pipe 3, and a drill bit 4.

[0023] Among them, the spiral drill rod 2 is rotatably installed inside the pipe pile 1, and one end of the spiral drill rod 2 passes through the pipe pile 1 and is successively connected to the jet - suction pipe 3 and the drill bit 4. The drill bit 4 is driven to rotate by the spiral drill rod 2 to complete the drilling operation.

[0024] Moreover, the spiral drill rod 2 and the pipe pile 1 can move synchronously in a direction perpendicular to the construction surface. The spiral drill rod 2 is of a hollow structure, and a mud pump 81 for inputting clear water is connected to the opening at the top end. The synchronous feeding of the spiral drill rod 2 and the pipe pile 1 ensures the coordinated advancement of drilling and follow - up pipe operations, avoids the risk of collapse of the hole wall due to lagging support, and guarantees the fitting accuracy between the pipe pile 1 and the formation during the pile - forming process. And by setting the spiral drill rod 2 as a hollow structure, the formed hollow channel inside it can provide a transmission path for high - pressure clear water, so that after the clear water is input by the mud pump 81, it can reach the jet - suction pipe 3 and the drill bit 4 directly, providing a power source for the subsequent operation of the jet - suction pipe 3 and a cleaning liquid for the drill bit 4.

[0025] Specifically, the jet - suction pipe 3 is communicated with the spiral drill rod 2 and the drill bit 4 for the transmission of clear water.

[0026] It should be noted that a jet - suction cavity 5 is formed inside the jet - suction pipe 3, and a suction port 51 communicating with the external environment is arranged on the jet - suction cavity 5. The suction port 51 is set to suck the broken particles formed during the drilling process.

[0027] When clear water flows through the jet - suction pipe 3 (as shown by the solid - line arrow in Figure 3 ), the jet - suction cavity 5 can form a negative - pressure chamber to suck the broken particles formed during the drilling process through the suction port 51 (as shown by the dotted - line arrow in Figure 3 ), so that the broken particles and the clear water form an abrasive water jet. That is, by forming a negative - pressure chamber in the jet - suction cavity 5 when the clear water is transmitted, the suction port 51 can actively suck the broken particles formed during the drilling process, and the broken particles are mixed with the clear water to form an abrasive water jet for subsequent ejection from the drill bit 4. And compared with the prior - art method of using mud as a cleaning liquid, this device does not need to rely on the mud pump 81 to suck sand - stone slurry during this process, thus effectively avoiding the problem of abrasion loss caused by the direct contact between the impeller and pipeline of the mud pump 81 and the broken particles, and improving the durability of the equipment.

[0028] In addition, due to the jet - entrainment effect of the jet - suction pipe 3 (as shown in Figure 3As shown by the dashed arrow in the figure, it can form a local circulating flow field at the bottom of the hole, and further improve the upward return velocity of the mixture formed by the broken particles (i.e., the cuttings located outside the jet suction pipe 3) and the clear water, so as to prevent the deposition of cuttings and enhance the chip-carrying effect of the clear water.

[0029] It should also be noted that the drill bit 4 has a nozzle assembly 6 for jetting clear water and the abrasive water jet. That is, through the abrasive water jet formed by the mixture of broken particles and clear water, when the drill bit 4 is running, it can significantly enhance the erosion ability and chip-carrying effect on the rock by virtue of the characteristics of the abrasive water jet, that is, complete the strengthening of the rock-breaking ability.

[0030] This device is provided with a jet suction pipe 3 with a jet suction cavity 5 formed inside and a suction port 51, and is connected to the hollow spiral drill pipe 2 and the drill bit 4 with a nozzle assembly 6, so that when clear water is input into the spiral drill pipe 2, the negative pressure entrainment effect of the jet suction cavity 5 can be used to automatically suck in the broken particles formed during the drilling process, and the broken particles can be mixed with the clear water to form an abrasive water jet and be ejected through the nozzle assembly 6 of the drill bit 4, so as to enhance the rock-breaking ability of the drill bit 4 by virtue of the characteristics of the abrasive water jet, that is, complete the strengthening of the rock-breaking ability.

[0031] Moreover, due to the jet entrainment effect of the jet suction pipe 3, it can form a local circulating flow field at the bottom of the hole, and further improve the upward return velocity of the mixture formed by the broken particles and the clear water, so as to prevent the deposition of cuttings and enhance the chip-carrying effect of the clear water.

[0032] In addition, this device uses the clear water input and the negative pressure chip suction mechanism of the jet suction pipe 3 to replace the application of mud as the cleaning fluid in the prior art, so that the mud pump 81 will not directly contact the particles in the mud during the whole process, thereby avoiding the wear of the mud pump 81, achieving the purpose of improving the durability of the equipment, simplifying the construction equipment and eliminating the risk of mud pollution.

[0033] Please continue to refer to Figure 3 In a further embodiment, a specific jet suction pipe 3 is also proposed to improve the entrainment effect on the broken particles and improve the rock-breaking ability of the subsequent drill bit 4.

[0034] Specifically, the jet suction pipe 3 includes a pipe body 31, a jet nozzle 32 and a throat pipe 33. The two ends of the pipe body 31 are respectively detachably and hermetically connected to the spiral drill pipe 2 and the drill bit 4. This connection method makes the jet suction pipe 3 have good maintainability and sealing performance in the whole system, which is convenient for the installation, disassembly and daily maintenance of the equipment. At the same time, it can effectively prevent the leakage of high-pressure clear water during the transmission process, ensure the stability of the system pressure, and provide a stable working environment for subsequent operations.

[0035] The jet nozzle 32 and the throat 33 are sequentially arranged in the pipe body 31 in a direction away from the auger stem 2, and a gap is reserved between the output end of the jet nozzle 32 and the throat 33, so that a jet suction chamber 5 capable of forming a negative pressure chamber is formed among the jet nozzle 32, the pipe body 31, and the throat 33.

[0036] That is, when high-pressure clean water (pressure is applied to the clean water when input by the mud pump 81) flows from the auger stem 2 to the jet nozzle 32, the jet nozzle 32 accelerates the clean water into a high-speed jet. Based on Bernoulli's principle, the high-speed jet will form a local low-pressure area at the gap formed between the output end of the jet nozzle 32 and the throat 33, thereby enabling the jet suction chamber 5 to form a negative pressure chamber. At this time, under the action of negative pressure, the suction port 51 will actively suck in the broken particles at the bottom of the hole, causing the broken particles to form an abrasive water jet, and then the abrasive water jet is input into the drill bit 4 together. Under the action of the nozzle assembly 6, the drill bit 4 ejects the abrasive water jet, thereby significantly enhancing the rock-breaking efficiency of the drill bit 4 and realizing the enhancement of the rock-breaking ability.

[0037] Moreover, in this process, since the jet suction chamber 5 can form a negative pressure chamber, and under the action of negative pressure, the suction port 51 will actively suck in the broken particles at the bottom of the hole, and thus a floating power will be provided to the broken particles (drill cuttings) and clean water at the bottom of the hole, thereby correspondingly increasing the upward return speed of the mixed liquid formed by the broken particles and the clean water, achieving the purpose of preventing drill cuttings from depositing and enhancing the chip-carrying effect of the clean water.

[0038] It should be noted that the centerlines of the jet nozzle 32, the throat 33, and the pipe body 31 coincide. When the jet suction pipe 3 is operating, it can rely on the characteristics of the jet to stably and efficiently form negative pressure, and more stably and efficiently suck in the broken particles at the bottom of the hole through the suction port 51 to form a uniform and highly abrasive abrasive water jet, further enhancing the rock-breaking efficiency of the drill bit 4 and realizing a more reliable enhancement of the rock-breaking ability.

[0039] In this embodiment, the throat 33 can prevent the fluid in the drill bit 4 from flowing back into the jet suction chamber 5, that is, it plays a role in preventing backflow.

[0040] As Figures 4 to 5 shown, in other embodiments, a specific drill bit 4 is also proposed to better complete the drilling operation.

[0041] Specifically, the drill bit 4 includes a cavity 41, a hole-expanding pick board 42, and a bottom pick board 43.

[0042] Among them, the hole-expanding pick board 42 is rotatably installed on the outer wall of the cavity 41 and has a closed state and an expanded state to meet the application requirements under different working conditions.

[0043] It should be noted that the closed state and the expanded state are switched by the rotation direction of the auger 2 and the reaction force received by the hole expanding cutter plate 42 when contacting the formation.

[0044] It should also be noted that when the hole expanding cutter plate 42 is in the closed state, the outer diameter of the drill bit 4 is smaller than the inner diameter of the pipe pile 1, which facilitates the detachment of the hole expanding cutter plate 42 from the pipe pile 1.

[0045] Wherein, a first flow channel 421 and a jet nozzle 422 communicated with the first flow channel 421 are arranged inside the hole expanding cutter plate 42.

[0046] Moreover, an installation seat for installing the hole expanding cutter plate 42 is formed on the outer side of the cavity 41, and a second flow channel 411 and a third flow channel 412 which are communicated with each other are respectively arranged on the cavity 41 and the installation seat.

[0047] Wherein, when the hole expanding cutter plate 42 is in the expanded state, the first flow channel 421, the second flow channel 411 and the third flow channel 412 are sequentially communicated, so that high-pressure fluid can enter the jet nozzle 422 through the first flow channel 421, the second flow channel 411 and the third flow channel 412 to form a high-speed jet flow.

[0048] In addition, when the hole expanding cutter plate 42 is in the closed state, the third flow channel 412 is disconnected from the first flow channel 421, and at this time, the rotating shaft of the hole expanding cutter plate 42 is just located at the outlet of the third flow channel 412, so that the high-pressure fluid can be ejected from the second flow channel 411 and the third flow channel 412 in sequence to complete the cleaning of the rotating shaft of the hole expanding cutter plate 42.

[0049] In this embodiment, by allowing high-pressure fluid to enter the hole expanding cutter plate 42 to form a high-speed jet flow, not only can the cleaning of the rotating shaft be completed through the high-speed jet flow, but also the soil layer in the area to be hole-expanded can be directly contacted to complete the auxiliary hole-expanding operation, so as to further enhance the drilling performance of the drill bit 4.

[0050] Please continue to refer to Figure 1 , in this embodiment, the system further includes a desanding cylinder 7, and the desanding cylinder 7 is detachably and fixedly installed on the outer wall of the end of the pipe pile 1.

[0051] Wherein, the auger 2 can convey the mixed liquid formed during the drilling process along the inner wall of the pipe pile 1 to the inside of the desanding cylinder 7.

[0052] In a specific example, a spiral blade is arranged on the outer wall of the auger 2, and the spiral blade is attached to the inner wall of the pipe pile 1, that is, the mixed liquid is conveyed by the way of screw conveyor, which is a conventional technical means in the prior art, so it will not be elaborated here.

[0053] In this embodiment, a recovery port 71 for recovering clear water in the mixed liquid is provided on one side of the top end of the sand removal cylinder 7. The mud pump 81 is connected to the recovery port 71 and the top opening of the screw drill rod 2 through pipelines for the recycling of clear water. Through this connection method, when the mixed liquid enters the sand removal cylinder 7, the separated clear water can be sucked out from the recovery port 71, that is, the mud pump 81 can transport the recovered clear water through the pipeline to the top opening of the screw drill rod 2 and enter the drill bit 4 again to participate in the operation. Even during the entire drilling operation process, by virtue of the recycling characteristics driven by the mud pump 81, the consumption of clear water can be significantly reduced, the construction cost can be lowered, and at the same time, the environmental pollution that may be caused by the large-scale discharge of the mixed liquid can be avoided, realizing the efficient utilization of resources and green construction.

[0054] Moreover, the inner cavity bottom wall of the sand removal cylinder 7 has an annular sand and gravel cavity 72 for collecting the broken particles in the mixed liquid, and a sand discharge port 721 is provided on one side of the annular sand and gravel cavity 72. When the mixed liquid enters the sand removal cylinder 7, under the action of gravity and the fluid movement in the sand removal cylinder 7, the broken particles in the mixed liquid will gradually settle and accumulate in the annular sand and gravel cavity 72, and the setting of the sand discharge port 721 enables the regularly discharging of the broken particles collected in the annular sand and gravel cavity 72. Through this design, when the sand removal cylinder 7 is operating, by virtue of the characteristics of the annular sand and gravel cavity 72 for collecting and the sand discharge port 721 for discharging the broken particles, the sand and gravel in the mixed liquid can be effectively separated, ensuring that the recovered clear water is relatively pure, and at the same time, avoiding the accumulation of broken particles from affecting the normal operation of the equipment, realizing the efficient and stable sand removal function and the reliable operation of the equipment.

[0055] In a further embodiment, a spiral blade 73 is fixedly installed on the inner wall of the sand removal cylinder 7 and is arranged in the opposite direction to the blades on the screw drill rod 2 for accelerating the separation and sedimentation of the broken particles in the mixed liquid. The spiral blade 73 will cause the mixed liquid entering the sand removal cylinder 7 to generate a swirling flow (i.e., centrifugal action), so that the broken particles in the mixed liquid will be thrown towards the inner wall of the sand removal cylinder 7 and then move downward along the direction of the spiral blade 73, while the clear water, due to its low density, remains in the central region and is sucked out by the mud pump 81 through the recovery port 71. Therefore, compared with the method of relying solely on gravity separation, the purpose of accelerating separation can be achieved.

[0056] Please continue to refer to Figure 1 , in other embodiments, the hydraulic drilling system is further defined to better realize the functions of efficient cooling of the drill bit 4 and assisting in rock breaking and chip removal.

[0057] Specifically, the hydraulic drilling system further includes a drilling rig 8, a mud pump 81, and a mud pit 82. The mud pump 81 and the mud pit 82 are both fixed on the drilling rig 8, which is convenient for movement during the construction process. At the same time, increasing the self-weight of the drilling rig 8 can provide a greater drilling pressure for the drill bit 4.

[0058] Among them, the mud pump 81 is connected to the top opening of the auger stem 2 through a pipeline connection structure and a swivel. Specifically, the swivel includes a rotating sleeve part and a fixed sleeve part arranged in sequence from bottom to top. One end of the rotating sleeve part is fixedly connected to the top opening of the auger stem 2, and the other end is rotatably connected to the fixed sleeve part. Moreover, the fixed sleeve part is connected to the mud pump 81 through a pipeline connection structure, so that when the auger stem 2 is helically fed, it will not interfere with the input of clear water, ensuring the stability of the equipment operation.

[0059] Embodiment 2 As Figures 6 to 8 shown, the difference between this embodiment and Embodiment 1 is that another structure of the drill bit 4 is proposed to optimize the structure between the cavity 41 and the reaming pick plate 42, further improving the drilling performance of the drill bit 4.

[0060] Specifically, the drill bit 4 includes a cavity 41, a reaming pick plate 42, and a bottom pick plate 43.

[0061] In this embodiment, the switching of the state of the reaming pick plate 42 is further explained as follows.

[0062] For example, when the auger stem 2 rotates clockwise (as shown by the Va direction in Figure 8 ), the reaming pick plate 42 is affected by the formation reaction force and changes from the closed state to the expanded state. In the expanded state, the cutting edges of the picks on the reaming pick plate 42 can perform reaming operations on the hole wall, making the diameter of the drilled hole match the outer diameter of the pipe pile 1, so as to ensure that the pipe pile 1 is closely attached to the formation, enhancing the stability of the pipe pile 1 in the hole and improving the bearing capacity of the entire pile foundation.

[0063] When the auger stem 2 rotates counterclockwise (i.e., in the direction opposite to Va), the reaming pick plate 42 is affected by the formation reaction force and returns from the expanded state to the closed state. At this time, the outer diameter of the reaming pick plate 42 is smaller than the inner diameter of the pipe pile 1, facilitating the smooth withdrawal of the drill bit 4 from the pipe pile 1, so that after the installation of the pipe pile 1 is completed, the drill bit 4 will not collide or get stuck with the pipe pile 1 during the withdrawal process, improving the construction efficiency and the service life of the equipment.

[0064] That is, through the design that the reaming pick plate 42 is rotatable and has two working states, when the drill bit 4 is operating, it can utilize the characteristics of different states of the reaming pick plate 42 to not only effectively ream the drilled hole, ensuring good bonding between the pipe pile 1 and the formation, but also facilitate the smooth withdrawal of the drill bit 4, improving the convenience of hole reaming and equipment operation.

[0065] Among them, the bottom pick plate 43 is fixedly installed at the bottom of the cavity 41 for drilling the bottom.

[0066] In other embodiments, a plurality of reaming pick plates 42 are provided, and the plurality of reaming pick plates 42 are arranged in a ring array centered on the axis of the cavity 41. In this embodiment, two reaming pick plates 42 are provided to improve the reaming rate.

[0067] In the prior art, the drill bit 4 is usually connected and assembled with other components through threads to ensure the sealing performance. However, in this embodiment, since the drill bit 4 needs to rotate in both forward and reverse directions, when simply using the thread method to complete the connection between the drill bit 4 and the injection suction pipe 3, there is a risk of loosening. Therefore, the connection relationship between the drill bit 4 and the injection suction pipe 3 is further defined here to improve the stability of the drill bit 4 during operation.

[0068] Specifically, the injection suction pipe 3 is hermetically connected to the drill bit 4 through threads, and a limit block installed by screws is provided on the outer wall of the cavity 41 of the drill bit 4, and a limit groove matching the limit block is provided on the outer wall of the injection suction pipe 3. When the injection suction pipe 3 and the drill bit 4 are completely thread-connected, the installation position of the limit block and the limit groove are just located in the same vertical plane. At this time, the limit block is installed on the outer wall of the cavity 41 to axially limit the injection suction pipe 3 and the drill bit 4, thereby achieving the purpose of improving the stability of the drill bit 4 during operation.

[0069] It should also be noted that the injection suction pipe 3 and the auger stem 2 are also connected in the same way as the injection suction pipe 3 and the drill bit 4 described above to ensure the connection sealing performance and stability, which will not be elaborated here.

[0070] Please continue to refer to Figures 6 to 8 , in this embodiment, the nozzle assembly 6 is further defined to improve the rock-breaking ability of the drill bit 4 and at the same time enable the drill bit 4 to stably switch between the closed state and the expanded state, avoiding situations such as jamming.

[0071] Specifically, the nozzle assembly 6 includes a first radial nozzle 61 and a second radial nozzle 62 provided in the cavity 41.

[0072] Among them, the opening direction of the first radial nozzle 61 faces the rotational connection between the corresponding reaming pick plate 42 and the cavity 41. By setting the opening direction of the first radial nozzle 61 to face the rotational connection between the reaming pick plate 42 and the cavity 41 (such as the rotating shaft), when the first radial nozzle 61 sprays low-pressure clean water, the clean water can directly act on this rotational connection to play a role in lubricating the rotating shaft, that is, reducing the friction between rotating parts, reducing wear, and extending the service life of the equipment. Moreover, it can also wash the rock debris deposited on the rotating shaft to avoid the accumulation of rock debris resulting in jamming when the reaming pick plate 42 switches states, ensuring that the reaming pick plate 42 can flexibly switch between the closed state and the expanded state and guaranteeing the normal operation of the equipment.

[0073] The opening direction of the second radial nozzle 62 faces the direction of the formation to be worked on when the hole enlarging pick plate 42 performs hole enlarging operations. By providing the second radial nozzle 62, it is used to spray high-pressure abrasive water jets. That is, when the hole enlarging pick plate 42 is performing hole enlarging operations, the high-pressure abrasive water jets can act on the formation to be broken in advance, assisting the hole enlarging pick plate 42 to break hard rock. Compared with relying solely on the mechanical breaking of the hole enlarging pick plate 42, the high-pressure abrasive water jets can first cause a certain degree of damage to the formation, reduce the strength of the formation, thereby reducing the mechanical load of the hole enlarging pick plate 42, improving the rock breaking efficiency, and at the same time reducing the wear of the hole enlarging pick plate 42 and extending the service life of the hole enlarging pick plate 42.

[0074] It should also be noted that when the hole enlarging pick plate 42 is in the closed state, the opening of the second radial nozzle 62 faces the corresponding hole enlarging pick plate 42, so that when the hole enlarging pick plate 42 switches from the closed state to the expanded state, the hole enlarging pick plate 42 can not only be subjected to the rotational power of the screw drill rod 2 and the reaction force of the formation, but also be assisted in expanding by means of the fluid power ejected from the second radial nozzle 62.

[0075] Among them, the inner diameter of the first radial nozzle 61 increases along the output direction, and the inner diameter of the second radial nozzle 62 decreases along the output direction. That is, the first radial nozzle 61 adopts a diffusive structure with an increasing inner diameter to reduce the jet velocity, increase the action area, reduce the erosion effect of the abrasive water jets on the rotating shaft of the hole enlarging pick plate 42, and strengthen the flushing effect. While the second radial nozzle 62 adopts a constrictive structure with a decreasing inner diameter to reduce the head loss, increase the jet velocity, enhance the impact force on the formation during hole enlarging operations, and further improve the flushing and cooling effect on the edge picks of the hole enlarging pick plate 42.

[0076] In a further embodiment, the nozzle assembly 6 further includes an axial nozzle 63 disposed in the cavity 41, which is used to assist the bottom pick plate 43 in performing drilling operations.

[0077] Embodiment III Based on Embodiment II, this embodiment also proposes a construction method for a pipe pile with follow-up casing while drilling, which is realized by using the hydraulic drilling system for pipe piles with follow-up casing described in Embodiment I. The specific steps are as follows: S1. Insert the screw drill rod 2 into the bottom of the pipe pile 1; S2. Control the screw drill rod 2 to rotate in a predetermined direction, driving the drill bit 4 to run synchronously to drill into the formation; S3. The clear water outputs power through the mud pump 81, enters the jet suction chamber 5 of the jet suction pipe 3 through the hollow cavity of the auger stem 2. Under the high-pressure impact of the clear water, a negative pressure chamber is formed in the jet suction chamber 5, so as to suck in real time the broken particles formed during the drilling process through the suction port 51, make the broken particles mix with the clear water to form an abrasive water jet, and spray out through the nozzle assembly 6 of the drill bit 4 to assist the drill bit 4 in rock breaking; S4. Control the pipe pile 1 to move downward along the direction perpendicular to the construction surface following the auger stem 2; S5. When the pipe pile 1 sinks to the preset depth, lift the auger stem 2, the jet suction pipe 3 and the drill bit 4 from the middle hole of the pipe pile 1 away from the hole bottom.

[0078] In this method, by controlling the rotation and feeding of the auger stem 2 and making the pipe pile 1 move downward synchronously, the clear water input by the mud pump 81 forms a negative pressure in the jet suction pipe 3 to entrain the broken particles, so that the broken particles mix with the clear water to form an abrasive water jet, and spray out through the nozzle assembly 6 of the drill bit 4 to complete the assistance of rock breaking and chip removal. When the pipe pile 1 sinks to the preset depth, the drill tool is separated to complete the construction and installation of the pipe pile 1. Since in this process, through the clear water input and the negative pressure chip suction mechanism of the jet suction pipe 3, the application of mud as the cleaning liquid in the prior art is replaced, so that the mud pump 81 does not directly contact the particles in the mud during the whole process, thereby avoiding the wear of the mud pump 81, and also achieving the purposes of improving the durability of the equipment, simplifying the construction equipment and eliminating the risk of mud pollution.

[0079] In other embodiments, step S2 further includes the following steps: When the drill bit 4 contacts the construction surface, input clear water to the top end of the auger stem 2 through the mud pump 81, so that the first radial nozzle 61 provides a jetting force for the hole expanding cutter plate 42 of the drill bit 4 to switch from the closed state to the expanded state. That is, through the directional jetting characteristic of the first radial nozzle 61, before the auger stem 2 starts to rotate, a jetting force consistent with its expanding direction can be applied to the hole expanding cutter plate 42, forming a "two-way drive" with the formation reaction force. Especially when in a hard rock formation or when the initial drilling resistance is large, the starting torque required for the hole expanding cutter plate 42 to open can be effectively reduced, avoiding the jamming phenomenon caused by excessive friction, ensuring that the hole expanding cutter plate 42 quickly and stably enters the working state, and improving the connection efficiency between the drilling and hole expanding processes and the equipment reliability.

[0080] In a further embodiment, step S5 is further described. For example, when it is necessary to control the auger stem 2, the jet suction pipe 3 and the drill bit 4 to be lifted from the middle of the pipe pile 1, it is necessary to control the auger stem 2 along a predetermined direction (such as Figure 8Rotate in the direction opposite to the Va direction (in the formation). At this time, under the reaction force of the formation, the reaming pick plate 42 deflects in the direction opposite to Va, thereby completing the switching of the reaming pick plate 42 from the expanded state to the closed state. And since the outer diameter of the reaming pick plate 42 is smaller than the inner diameter of the pipe pile 1 when it is in the closed state, no interference will be formed during the lifting process, improving the stability of the construction process.

[0081] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A hydraulic drilling system for follow - the - pipe pile while drilling, characterized in that, It includes a pipe pile, a spiral drill rod, a jet suction pipe and a drill bit; The spiral drill rod is rotatably installed inside the pipe pile, and one end of the spiral drill rod passes through the pipe pile and is sequentially connected to the jet suction pipe and the drill bit; Wherein, the spiral drill rod and the pipe pile can move synchronously in a direction perpendicular to the construction surface, and the spiral drill rod is a hollow structure, and a mud pump for inputting clear water is connected to the opening at the top end; The jet suction pipe is communicated with the spiral drill rod and the drill bit for transmitting clear water; Wherein, a jet suction cavity is formed inside the jet suction pipe, and a suction port communicated with the external environment is arranged on the jet suction cavity; When clear water flows through the jet suction pipe, the jet suction cavity can form a negative pressure chamber to suck the broken particles formed during the drilling process through the suction port, so that the broken particles and the clear water form an abrasive water jet; The drill bit has a nozzle assembly for jetting clear water and the abrasive water jet.

2. The hydraulic drilling system for the pipe-jacking pile while drilling as claimed in claim 1, wherein, The jet suction pipe includes a pipe body, a jet nozzle and a throat pipe; Both ends of the pipe body are detachably and hermetically connected to the spiral drill rod and the drill bit respectively; The jet nozzle and the throat pipe are sequentially arranged inside the pipe body from the direction away from the spiral drill rod, and a gap is reserved between the output end of the jet nozzle and the throat pipe, so that the jet nozzle, the pipe body and the throat pipe surround to form the jet suction cavity capable of forming a negative pressure chamber.

3. The hydraulic drilling system for follow - the - pipe pile while drilling according to claim 1, characterized in that, The drill bit includes a cavity, an underreaming pick plate and a bottom pick plate; The underreaming pick plate is rotatably installed on the outer wall of the cavity and has a closed state and an expanded state; Wherein, the closed state and the expanded state are switched by the rotation direction of the spiral drill rod and the reaction force received by the underreaming pick plate when contacting the formation; And when the underreaming pick plate is in the closed state, the outer diameter of the drill bit is smaller than the inner diameter of the pipe pile; The bottom pick plate is fixedly installed at the bottom of the cavity.

4. The hydraulic drilling system for the pipe-jacking pile while drilling according to claim 3, characterized in that, The underreaming pick plate is internally provided with a first flow channel and a jet nozzle communicated with the first flow channel; An installation seat for installing the underreaming pick plate is formed on the outer side of the cavity, and a second flow channel and a third flow channel communicated with each other are respectively arranged on the cavity and the installation seat; When the underreaming pick plate is in the expanded state, the first flow channel, the second flow channel and the third flow channel are sequentially communicated; When the underreaming pick plate is in the closed state, the third flow channel is disconnected from the first flow channel, and the outlet of the third flow channel just faces the rotating shaft of the underreaming pick plate.

5. The hydraulic drilling system for the pipe-jacking pile while drilling according to claim 3, wherein, A plurality of the underreaming pick plates are provided, and the plurality of underreaming pick plates are arranged in a circular array centered on the axis of the cavity.

6. The hydraulic drilling system for the pipe - following pile while drilling according to claim 3, characterized in that, The nozzle assembly includes a first radial nozzle and a second radial nozzle arranged in the cavity; The opening direction of the first radial nozzle faces the rotating connection between the corresponding underreaming pick plate and the cavity; The opening direction of the second radial nozzle faces the direction to be operated when the corresponding underreaming pick plate performs underreaming operation; Wherein, when the underreaming pick plate is in the closed state, the opening of the second radial nozzle faces the corresponding underreaming pick plate; The inner diameter of the first radial nozzle increases along the output direction, and the inner diameter of the second radial nozzle decreases along the output direction.

7. The hydraulic drilling system for the pipe jacking pile while drilling according to claim 3, wherein, The nozzle assembly further includes an axial nozzle disposed in the cavity for assisting the bottom pick plate in drilling operations.

8. The hydraulic drilling system for the pipe-jacking pile while drilling according to claim 1, characterized in that, It further includes a sand removal cylinder; The sand removal cylinder is detachably and fixedly installed on the outer wall of the end of the pipe pile, and the auger can convey the mixed liquid formed during the drilling process along the inner wall of the pipe pile into the sand removal cylinder; One side of the top end of the sand removal cylinder is provided with a recovery port for recovering the clear water in the mixed liquid. The mud pump is connected to the recovery port and the top opening of the auger through a pipeline for the recycling of clear water; The inner cavity bottom wall of the sand removal cylinder has an annular sand cavity for collecting the broken particles in the mixed liquid, and a sand discharge port is provided on one side of the annular sand cavity; The inner wall of the sand removal cylinder is also fixedly installed with a spiral blade arranged in the opposite direction to the blades on the auger for accelerating the separation and deposition of the broken particles in the mixed liquid.

9. The hydraulic drilling system for the pipe-jacking pile while drilling according to claim 1, characterized in that, The hydraulic drilling system further includes a drilling rig and a mud pit connected to the auger; The mud pit and the mud pump are both fixed on the drilling rig, and the mud pit is communicated with the recovery port; The mud pump is used to output the clear water input into the mud pit to the top opening of the auger.

10. A construction method for a pipe-jacking pile while drilling, characterized in that, It is realized by using the hydraulic drilling system for the follow - up pipe pile during drilling as described in any one of claims 1 - 9, and specifically includes the following steps: S1. Insert the auger into the bottom of the pipe pile; S2. Control the auger to rotate in a predetermined direction, driving the drill bit to operate synchronously to drill into the formation; S3. The clear water outputs power through the mud pump and enters the jet suction chamber of the jet suction pipe through the hollow cavity of the auger. Under the high - pressure impact of the clear water, a negative pressure chamber is formed in the jet suction chamber to suck in real - time the broken particles formed during the drilling process through the suction port, making the broken particles mix with the clear water to form an abrasive water jet, which is ejected from the nozzle assembly of the drill bit to assist the drill bit in rock breaking; S4. Control the pipe pile to move downward along the direction perpendicular to the construction surface following the auger; S5. When the pipe pile sinks to the preset depth, lift the auger, the jet suction pipe and the drill bit from the bottom of the middle hole of the pipe pile.

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