A construction technology for expanding the hole of a bridge's super-large diameter pile foundation

Abstract

This application relates to the technical field of bridge engineering and discloses a construction process for expanding a large-diameter pile foundation for a bridge. The process comprises the following steps: S1: constructing a movable base corresponding to a steel casing on a construction platform, with the distance between the two movable bases adapted to the distance between the two crawlers of a rotary drilling rig; S2: driving the rotary drilling rig onto the movable base; S3: the rotary drilling rig driving its own drill rod downward into the steel casing; S4: the drill rod driving the drill bit downward through the steel casing to the riverbed rock and soil layer to drill a hole in the riverbed, the drill bit drilling down to the hole bottom elevation and removing slag, which is stored in a slag box; S5: replacing the rotary drilling rig, and after the previous rotary drilling rig exits, adjusting the distance between the two movable bases to adapt to the distance between the two crawlers of the next rotary drilling rig; S6: repeating S2-S5 until the expanded hole inner diameter reaches a predetermined value for the pile foundation. This application can improve drilling efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of bridge engineering, and in particular to a construction process for expanding a bridge's super-large diameter pile foundation. Background Art

[0002] Bridge pile foundations are usually built in river channels. First, a construction platform must be built in the river channel. A through hole corresponding to the pile foundation must be opened on the construction platform. A steel casing extending to the rock and soil layer of the riverbed is installed in the through hole. The inside of the casing is cleaned, and then the drill bit of the rotary drilling rig is inserted into the casing to drill downwards. After drilling is completed, concrete is poured into the hole.

[0003] When drilling holes in pile foundations with extra-large diameters, it is difficult to drill a hole using only a drill bit that is suitable for the pile foundation diameter. Different types of rotary drilling rigs are required. Different rotary drilling rigs are equipped with drill bits of different diameters. Use drill bits with diameters from small to large to drill holes in sequence and gradually expand the holes.

[0004] Among them, the rotary drilling rig includes a base, a fuselage, a drill rod and a drill bit. Tracks are installed on both sides of the base to drive the base to move. The fuselage is installed on the base, the drill rod is installed on the fuselage, and the drill bit is coaxially installed at the bottom of the drill rod and located between the two tracks, and the two tracks are symmetrical with the drill rod as the center.

[0005] Regarding the above-mentioned related technologies, for the expansion of pile foundations with ultra-large diameters, due to the different distances between the two crawlers on different types of rotary drilling rigs, when a smaller rotary drilling rig moves to the upper end of the steel casing on the construction platform, the crawlers will be partially suspended because the straight-line distance of the gap between the crawlers is smaller than the inner diameter of the steel casing, causing the rotary drilling rig to be unstable and affecting the drilling effect. Summary of the Invention

[0006] In order to improve the drilling effect, the present application provides a bridge super-large diameter pile foundation hole expansion construction process.

[0007] This application provides a bridge super-large diameter pile foundation hole expansion construction process, which adopts the following technical solutions:

[0008] A bridge super-large diameter pile foundation hole expansion construction process includes the following steps:

[0009] S1, building movable seats corresponding to the steel casings on the construction platform, each steel casing corresponding to two movable seats, and the distance between the two movable seats adapts to the distance between the two crawlers of the rotary drilling rig;

[0010] S2, driving the rotary drilling rig onto the movable base, so that the two movable bases respectively support the two crawlers of the rotary drilling rig;

[0011] S3, the rotary drilling rig drives its own drill rod to move downward into the steel casing, and moves the rotary drilling rig on the moving base until the drill rod and the steel casing are coaxial;

[0012] S4, the drill rod drives the drill bit downward through the steel casing to reach the riverbed rock layer to drill the riverbed, the drill bit drills downward to the hole bottom elevation and removes the slag, and the removed slag is stored in a slag box;

[0013] S5, replacing the rotary drilling rig, the distance between the two movable bases being adjustable, after the previous rotary drilling rig exits, adjusting the distance between the two movable bases to be compatible with the distance between the two crawlers of the next rotary drilling rig, the drill bit size of the next rotary drilling rig being larger than the drill bit size of the previous rotary drilling rig;

[0014] S6, repeat S2-S5 until the expanded pore inner diameter reaches the predetermined value of the pile foundation.

[0015] By adopting the above technical solution, the crawler of the rotary drilling rig is supported by setting a movable seat, so that the crawler of the rotary drilling rig will not be suspended in the air, and by adjusting the distance between the two movable seats, the distance between the two movable seats can be adapted to the distance of different crawler tracks of the rotary drilling rig, so as to improve the stability of the rotary drilling rig during drilling, thereby improving the drilling effect.

[0016] Optionally, in S1, a base is built on the construction platform, the movable seat slides on the base, and the base has a driving member, which is used to drive the two movable seats to move toward or away from each other.

[0017] By adopting the above technical solution, the driving member drives the two movable seats to move away from or towards each other, so that the distance between the two movable seats can be evenly adjusted.

[0018] Optionally, the driving member includes a bidirectional screw and a driving motor, the bidirectional screw is rotatably connected to the base, the driving motor is installed on the base to drive the bidirectional screw to rotate, the bidirectional screw has a forward-rotating part and a reverse-rotating part with opposite threads, and the two movable seats are respectively threadedly connected to the forward-rotating part and the reverse-rotating part.

[0019] By adopting the above technical solution, the driving motor drives the bidirectional screw to rotate, which can drive the two moving seats that move with the threads of the forward rotation part and the reverse rotation part respectively to move away from or towards each other.

[0020] Optionally, in S3, a correction seat is used to point the drill pipe, the correction seat is located in the steel casing, the correction seat has a cavity, and the correction seat is hinged to the cavity with a plurality of synchronously rotating pointing rods;

[0021] During use, the drill bit is passed downward through the cavity so that the drill rod is opposite to the cavity, and then the pointing rod is rotated into the cavity. At the same time, the rotary drilling rig is moved until the drill rod is against all the pointing rods in the correction seat, that is, the drill rod and the steel casing are coaxially arranged.

[0022] By adopting the above technical solution, the pointing rods are turned synchronously so that the pointing rods together enclose a space that is coaxially arranged with the steel casing, thereby pointing the position of the drill rod and enabling the drill rod to be adjusted to a position that abuts all the pointing rods, so that the drill rod and the steel casing are coaxially arranged.

[0023] Optionally, the correction seat and the cavity are coaxial with the steel casing, a plurality of the pointing rods are evenly spaced on the correction seat, and the correction seat is coaxially provided with a gear ring that engages with the hinges of all the pointing rods. The correction seat is also provided with an elastic member connected to the gear ring, and the elastic member gives the gear ring a tendency to rotate, so as to drive the pointing rod to rotate closer to the cavity.

[0024] By adopting the above technical solution, the elastic member drives the gear ring to rotate, so that the pointing rod can automatically adjust the position of contact with the drill rod, thereby enabling the pointing rod to point to drill rods of different sizes.

[0025] Optionally, the elastic member is a first spring, a first connecting portion is provided in the correction seat, a second connecting portion is provided on the outer wall of the gear ring, and the first spring is connected between the first connecting portion and the second connecting portion;

[0026] The correction seat is provided with a mounting cavity connected to the second connecting portion, a first seat is provided in the mounting cavity, a suction portion for attracting the second connecting portion is provided in the first seat and moves up and down, and a second spring is provided in the first seat for driving the suction portion to move downward, and a connecting rope connected to the suction portion is provided on the movable seat;

[0027] In S3, before the drill bit passes through the cavity, the connecting rope is reeled in to drive the suction part to move upward, so that the suction part moves upward to be opposite to the second connecting part, so that the second connecting part is attracted by the suction part and moves, so that the pointing rod is rotated and stored in the direction of leaving the cavity, and then the drill bit is passed downward through the cavity; when the drill bit is located under the correction seat, the connecting rope is unreeled, so that the suction part moves downward under the drive of the second spring to be staggered with the second connecting part, and the second connecting part drives the gear ring to rotate under the action of the first spring, so that the pointing rod rotates toward the center of the cavity.

[0028] By adopting the above technical solution, the suction part is pulled by the connecting rope to move the suction part to a position opposite to the second connecting part, so that the second connecting part drives the gear ring to rotate, so that the pointing rod rotates in the direction away from the cavity, and the middle part of the correction seat has space for the drill bit and the drill rod to pass through the correction seat.

[0029] Optionally, the correction seat slides up and down in the steel casing, and the correction seat has a second seat connected to the first seat in the installation cavity, the first seat and the second seat slide together in the installation cavity, and a magnetic strip corresponding to the second seat is embedded on the inner wall of the bottom of the steel casing, and the second seat and the magnetic strip repel each other;

[0030] In S4, when the drill bit moves downward, the connecting rope is unwound to move the second seat to the bottom of the steel casing. The second seat is repelled by the magnetic strip and moves to be opposite to the second connecting part. The second connecting part is attracted by the second seat and moves away from the inner wall of the steel casing, so that the second seat is opposite to the second connecting part, and the first seat and the second connecting part are offset, so that the pointing rod is retracted in the direction of leaving the cavity.

[0031] By adopting the above technical solution, the connecting rope is unwound so that the correction seat moves downward with the drill rod when the pointing rod abuts the drill rod, thereby further guiding the movement of the drill rod. When the drill rod needs to rotate to drive the drill bit to drill a hole downward, the second seat is repelled by the magnetic strip and replaces the position of the first seat to be opposite to the second connecting part. The second connecting part is attracted by the second seat and drives the gear ring to rotate, so that the pointing rod rotates away from the drill rod, so that the drill rod is not easily hindered by the pointing rod when rotating.

[0032] Optionally, a roller for reeling and unreeling the connecting rope is rotatably connected to the movable seat, and a power source for driving the roller to rotate is installed on the movable seat.

[0033] By adopting the above technical solution, the power source drives the winding roller to rotate, which can drive the connecting rope to be reeled in and unreeled.

[0034] In summary, this application has the following beneficial effects:

[0035] By setting a moving seat and adjusting the position between the two moving seats, the moving seat supports the crawler of the rotary drilling rig, so that the crawler of the rotary drilling rig is not easily suspended in the air, thereby improving the stability of the rotary drilling rig when drilling, and through the correction seat, the drill rod of the rotary drilling rig is pointed to be coaxial with the steel casing, thereby improving the drilling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural diagram of an embodiment of the present application;

[0037] Figure 2 This is a schematic structural diagram of a single steel casing according to an embodiment of the present application;

[0038] Figure 3 is a cross-sectional view of a correction seat according to an embodiment of the present application;

[0039] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure at A in the middle;

[0040] Figure 5 It is a schematic diagram of the exploded structure of the correction seat, the first seat and the second seat in the embodiment of the present application;

[0041] Figure 6 yes Figure 5 Schematic diagram of the enlarged structure at B in the middle;

[0042] Figure 7 This is a schematic diagram of the coordination structure of the movable seat and the correction seat according to an embodiment of the present application;

[0043] Figure 8 Figure 7 Schematic diagram of the enlarged structure at C in the middle;

[0044] Figure 9 It is a cross-sectional view of the steel casing according to an embodiment of the present application.

[0045] Explanation of Reference Numerals: 1. Steel casing; 2. Moving seat; 3. Base; 4. Driving member; 41. Bidirectional screw; 411. Forward rotation portion; 412. Counter-rotation portion; 42. Driving motor; 5. Correction seat; 6. Cavity; 7. Pointing rod; 8. Gear ring; 9. First spring; 10. First connecting portion; 11. Second connecting portion; 12. Mounting cavity; 13. First seat; 14. Suction portion; 15. Second spring; 16. Connecting rope; 17. Second seat; 18. Magnetic strip; 19. Roller; 20. Power source; 21. Operating chamber; 22. Hinge slot; 23. Rotating shaft; 24. Ring; 25. Adjusting tooth; 26. Arc slot; 27. Ring slot; 28. Connecting slot; 29. Partition; 30. Connecting port; 31. Exposure port; 32. Guide block; 33. Guide slot; 34. Limit block; 35. Winding slot; 36. Through slot; 37. Travel block; 38. Travel slot. DETAILED DESCRIPTION

[0046] The following is combined with Figure 1-9 This application is described in further detail.

[0047] The present invention discloses a bridge super-large diameter pile foundation hole enlargement construction process. The bridge super-large diameter pile foundation hole enlargement construction process includes the following steps:

[0048] S1. Build a base 3 and a mobile base 2 corresponding to the steel casing 1 on the construction platform. Each steel casing 1 corresponds to two mobile bases 2. The two mobile bases 2 are parallel to each other and move on the base 3 in the direction of approaching or moving away from each other. The two relatively mobile bases 2 are symmetrically arranged with the central axis of the steel casing 1 as the center. The base 3 has a driving member 4 for driving the two relatively mobile bases 2 to move. The driving member 4 is used to adjust the distance between the two mobile bases 2 to adapt to the distance between the two crawlers of the rotary drilling rig;

[0049] S2, align the two crawlers of the rotary drilling rig with the two opposite mobile bases 2, then drive the rotary drilling rig onto the mobile bases 2, so that the drill rod and drill bit of the rotary drilling rig are located between the two mobile bases 2, and the two opposite mobile bases 2 respectively support the two crawlers of the rotary drilling rig;

[0050] S3, the drill rod of the rotary drilling rig drives the drill bit downward into the steel casing 1. A correction seat 5 is coaxially and detachably provided in the steel casing 1. A cavity 6 is coaxially formed on the correction seat 5. A plurality of pointing rods 7 for guiding the position of the drill rod are hingedly connected to the correction seat 5 in the cavity 6. When the drill bit passes through the cavity 6 and is located below the correction seat 5, the drill bit is stopped from being lowered, and the position of the drill rod is corrected by the pointing rods 7. The rotary drilling rig is moved so that the drill rod is coaxial with the steel casing 1 under the guidance of the pointing rods 7;

[0051] S4, continue to lower the drill rod to drive the drill bit to move downward, and at the same time, the correction seat 5 moves downward together with the drill rod to guide the drill rod. When the drill bit reaches the riverbed rock and soil layer, the correction seat 5 is separated from the drill rod, and then the drill bit drills the riverbed rock and soil layer. After the drill bit drills to a certain depth, the slag is removed and the steel casing 1 is moved upward. The waste slag is stored in the slag box, and then the drill bit is lowered again to continue drilling and removing the slag until the drilling depth reaches the hole bottom elevation;

[0052] S5, replace the rotary drilling rig, the outer diameter of the drill rod of the latter rotary drilling rig is larger than the outer diameter of the drill rod of the former rotary drilling rig, and the outer diameter of the drill bit of the latter rotary drilling rig is larger than the outer diameter of the drill bit of the former rotary drilling rig. After the former rotary drilling rig is withdrawn from the movable base 2, the distance between the two movable bases 2 is adjusted to adapt to the distance between the two crawlers of the latter rotary drilling rig;

[0053] S6, repeat S2-S5 until the outer diameter of the drill bit is larger than the inner diameter of the correction seat 5;

[0054] S7, remove the base 3, the movable base 2 and the correction base 5 from the current construction platform and the steel casing 1, and then use the rotary drilling rig to continue expanding the hole to the bottom elevation. At this time, the outer diameter of the rotary drilling rig drill bit is consistent with the inner diameter of the steel casing 1 to adapt to the predetermined value of the pile foundation.

[0055] Reference Figure 1 and Figure 2In S1, the base 3 is long and has two fixed seats at opposite ends that are fixed to the construction platform by screws. The lower surface of the movable base 2 abuts against the upper surface of the construction platform, and the two movable bases 2 are slidably mounted on the outer wall of the base 3 along the length direction of the base 3.

[0056] Reference Figure 2 The driving member 4 includes a bidirectional screw 41 and a drive motor 42. The base 3 has an operating chamber 21 defined on its upper surface. The bidirectional screw 41 is rotatably connected to the operating chamber 21 of the base 3, with the axis of the bidirectional screw 41 parallel to the length of the base 3. The drive motor 42 is fixed to one end of the base 3. One end of the bidirectional screw 41 extends out of the base 3 and is connected to the output end of the drive motor 42, so that the drive motor 42 can drive the bidirectional screw 41 to rotate.

[0057] The bidirectional screw 41 has a forward-rotating portion 411 and a reverse-rotating portion 412 extending from its midpoint, with threads in opposite directions. The two opposing movable seats 2 have mating portions extending into the operating chamber 21. The mating portions on the two movable seats 2 are threadedly connected to the forward-rotating portion 411 and the reverse-rotating portion 412, respectively. Thus, when the bidirectional screw 41 rotates, it drives the two movable seats 2 to move away from or toward each other.

[0058] Reference Figure 2 and Figure 3 The correction seat 5 having a cavity 6 is annular in shape. The outer diameter of the correction seat 5 is equivalent to the inner diameter of the steel casing 1. When the correction seat 5 is located inside the steel casing 1, it is coaxial with the steel casing 1. There are four pointing rods 7. Four hinge grooves 22 are evenly spaced on the inner wall of the correction seat 5. One end of the four pointing rods 7 is hinged in the four hinge grooves 22 respectively.

[0059] Reference Figure 4 Specifically, a rotating shaft 23 is fixed in each hinge groove 22, and the axial direction of the rotating shaft 23 is parallel to the axial direction of the correction seat 5. The end of the pointing rod 7 has a ring 24 that is coaxially rotatable and sleeved on the outer wall of the corresponding rotating shaft 23. A plurality of adjusting teeth 25 are evenly spaced on the outer wall of the ring 24.

[0060] Reference Figure 3 and Figure 5 An arc groove 26 is coaxially provided on the inner wall of the correction seat 5 and is connected to the hinge groove 22. The arc groove 26 corresponds to the hinge groove 22 one by one. When the pointing rod 7 rotates toward the outside of the hinge seat, the end of the pointing rod 7 away from its own hinge point can be pushed into the arc groove 26. When all the pointing rods 7 are pushed into the arc groove 26, there is space in the middle of the correction seat 5 for the drill bit and drill rod to pass through.

[0061] Reference Figure 3 and Figure 4An annular groove 27 is coaxially defined within the correction base 5 and communicates with the hinge groove 22. The correction base 5 is coaxially connected to the gear ring 8 within the annular groove 27, and the inner diameter of the annular groove 27 is larger than the outer diameter of the arc groove 26. The inner wall of the gear ring 8 is evenly spaced with teeth. The adjustment teeth 25 of all the collars 24 within the correction base 5 mesh with the teeth of the gear ring 8, so that when the gear ring 8 rotates, all the directional rods 7 on the correction base 5 rotate synchronously.

[0062] A connecting groove 28 is provided in the correction seat 5, which is opposite to the outer wall of the gear ring 8. The connecting groove 28 corresponds one-to-one to the pointing rod 7. The inner wall of one end of the correction seat 5 in the connecting groove 28 is a first connecting portion 10. The outer wall of the gear ring 8 is fixed with a second connecting portion 11 extending into the connecting groove 28. There is an elastic member between the first connecting portion 10 and the second connecting portion 11, and the elastic member is a first spring 9. The first spring 9 gives the second connecting portion 11 a tendency to move toward the first connecting portion 10.

[0063] Under the action of the first spring 9 , the second connecting portion 11 is driven to move toward the first connecting portion 10 , thereby driving the gear ring 8 to rotate, causing the pointing rod 7 to rotate toward the interior of the correction seat 5 .

[0064] In S3, when the drill bit passes downward through the cavity 6 and the correction seat 5, and the drill rod is located in the correction seat 5 and is opposite to the correction seat 5, the pointing rod 7 rotates into the correction seat 5 under the action of the first spring 9, and the pointing rods 7 can jointly enclose and abut the drill rod. As the rotary drilling rig moves on the moving seat 2, the drill rod is adjusted in position in the correction seat 5, and the position of the pointing rod 7 changes adaptively. When the drill rod moves until the four pointing rods 7 all abut against the drill rod, the drill rod position adjustment is completed. At this time, the drill rod is coaxial with the steel casing 1.

[0065] Reference Figure 4 and Figure 6 To prevent the pointing rod 7 from interfering with the drill bit's movement as it passes through the cavity 6 and the correction base 5, the correction base 5 includes an attraction portion 14 for attracting the second connection portion 11 away from the first connection portion 10. The attraction portion 14 has a magnetic attraction force capable of attracting the second connection portion 11, which is made of iron. The attraction portion 14 corresponds one-to-one with the second connection portion 11.

[0066] Specifically, an installation cavity 12 is opened inward on the outer peripheral side of the correction seat 5, and a partition 29 is provided between the installation cavity 12 and the connecting groove 28. The partition 29 has a connecting port 30 that connects the installation cavity 12 and the connecting groove 28. The second connecting part 11 is closer to the connecting port 30 than the first connecting part 10.

[0067] Within the mounting cavity 12, the correction seat 5 slides toward or away from the outer wall of the correction seat 5. This first seat 13 is made of plastic and is not attracted by the suction portion 14. It is composed of two halves joined together. The interior of the first seat 13 is hollow. The suction portion 14 is a square structure that slides up and down within the first seat 13. A second spring 15 is connected between the inner top wall of the first seat 13 and the upper surface of the suction seat. This second spring 15 imparts a downward bias to the suction portion 14. When the suction portion 14 moves downward until it abuts the inner bottom wall of the first seat 13, the second spring 15 is compressed.

[0068] A surface of the first seat 13, adjacent to the barrier 29, defines an exposed opening 31 communicating with the interior of the first seat 13. When the first seat 13 is moved to face the communicating opening 30, the exposed opening 31 faces the communicating opening 30, thereby allowing the connection groove 28 to communicate with the interior of the first seat 13. A connecting rope 16 is fixedly connected to the suction portion 14. The end of the connecting rope 16, distal from the suction portion 14, slides upward, passes through the first seat 13, and extends out of the steel casing 1 to connect to the movable seat 2.

[0069] Reference Figure 2 and Figure 5 A guide block 32 is fixed on the outer wall of the correction seat 5, and a guide groove 33 is provided on the inner wall of the steel casing 1 for the limit block 34 to slide up and down. The guide groove 33 passes through the upper surface of the steel casing 1, and the steel casing 1 is detachably installed with the limit block 34 on the upper part of the guide groove 33 by bolts. When the upper surface of the guide block 32 abuts against the lower surface of the limit block 34, the upper surface of the correction seat 5 is flush with the upper surface of the steel casing 1 and the upper surface of the construction platform.

[0070] Reference Figure 2 and Figure 4 In S3, when the drill bit needs to be moved downward through the correction seat 5, the connecting rope 16 is pulled upward, and the first seat 13 can be pulled to be opposite to the connecting port 30, so that the connecting groove 28 is connected to the inside of the first seat 13, and the elastic force of the second spring 15 drives the guide block 32 to move upward to abut against the limit block 34, and then the connecting rope 16 is continued to be pulled upward, so that the suction part 14 overcomes the elastic force of the second spring 15 and moves upward, and the suction part 14 can be moved to be opposite to the exposure port 31. At this time, the second connecting part 11 is attracted by the suction part 14 and overcomes the elastic force of the first spring 9 to move toward the suction part 14, so that the gear ring 8 drives the pointing rod 7 to abut against the arc groove 26, so that the drill bit does not interfere with the pointing rod 7, and then the drill bit is passed downward through the correction seat 5.

[0071] Reference Figure 4 and Figure 6When the drill bit is located below the correction seat 5 and the pointing rod 7 needs to be used to point the position of the drill rod, the connecting rope 16 is lowered, and the elastic force of the second spring 15 overcomes the attraction between the suction part 14 and the second connecting part 11 and the gravity of the correction seat 5, driving the suction part 14 to move downward until it is offset from the exposure opening 31. As a result, the suction part 14 is not able to attract the second connecting part 11 due to the isolation of the first seat 13, so that the second connecting part 11 is driven by the elastic force of the first spring 9 to rotate the pointing rod 7 into the correction seat 5, thereby causing the pointing rod 7 to abut against the drill rod.

[0072] Reference Figure 7 and Figure 8 Among them, the two relatively movable seats 2 are both rotatably connected with a winding roller 19, and the winding rollers 19 of the two movable seats 2 are parallel to each other. Each winding roller 19 has two winding grooves 35 along its own circumference. The bottom of the movable seat 2 is provided with a through groove 36 connected to the winding groove 35, and the through groove 36 runs through the side of the two movable seats 2 that are close to each other.

[0073] Reference Figure 6 and Figure 8 The connecting ropes 16 connected to the four suction parts 14 are respectively wound up in different winding grooves 35 through the through grooves 36, and the distance between each connecting rope 16 and the winding roller 19 is consistent. The movable base 2 is equipped with a power source 20 for driving the winding roller 19 to rotate. The power source 20 is a power motor with an output end connected to the winding roller 19. The two power motors on the two movable bases 2 operate simultaneously, so that the winding rollers 19 on the two movable bases 2 simultaneously wind up or unwind the connecting ropes 16. The winding rollers 19 wind up the connecting ropes 16, thereby pulling the suction part 14 upward.

[0074] Reference Figure 5 When the connecting rope 16 is unwound, the pointing rod 7 abuts against the drill rod. In S4, when the drill bit moves downward, the connecting rope 16 is unwound at the same time. Under the combined action of the friction between the drill rod and the pointing rod 7 and the gravity of the correction seat 5 itself, the drill rod can drive the correction seat 5 to move downward together, so that the correction seat 5 further guides the movement of the drill rod.

[0075] Reference Figure 4 and Figure 6 A second seat 17 is fixed to one side of the first seat 13 close to the outer wall of the correction seat 5. The second seat 17 slides together with the first seat 13 in the installation cavity 12, and a travel block 37 is fixed on the outer walls of the first seat 13 and the second seat 17. The correction seat 5 is provided with a travel groove 38 on the inner wall of the installation cavity 12 for the travel block 37 to slide, so as to limit the first seat 13 and the second seat 17 from sliding out of the installation cavity 12.

[0076] Reference Figure 4 and Figure 8A magnetic strip 18 is fixedly embedded on the inner wall of the bottom of the steel casing 1, and the second seat 17 has magnetism that repel the magnetic strip 18. In S4, when the drill bit approaches the bottom of the steel casing 1, the guide block 32 abuts against the bottom wall of the guide groove 33 to limit the correction seat 5 from continuing to move downward, and at this time the second seat 17 is opposite to the magnetic strip 18. Since the second seat 17 and the magnetic strip 18 repel each other, the second seat 17 drives the first seat 13 to move away from the outer wall of the correction seat 5 until the first seat 13 abuts against the inner wall of the installation cavity 12. At this time, the second seat 17 replaces the first seat 13 and is opposite to the connecting port 30. The magnetism of the second seat 17 causes the second connecting part 11 to resist the elastic force of the first spring 9 and move toward the second seat 17, thereby driving the pointing rod 7 to loosen the drill rod, so that the drill rod drives the drill bit to rotate and drill the riverbed without interfering with the pointing rod 7.

[0077] In S4, when the drill rod needs to be moved upward, the connecting rope 16 is wound up at the same time to drive the correction seat 5 to move upward and reset. When the connecting rope 16 is wound up, it gives the first seat 13 a tendency to move toward the outer wall of the correction seat 5, thereby driving the first seat 13 and the second seat 17 to move toward the outer wall of the correction seat 5, even if the first seat 13 replaces the second seat 17 and is opposite to the connecting port 30.

[0078] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A bridge super-large diameter pile foundation hole expansion construction process, characterized by: The following steps are included: S1, building a movable seat (2) corresponding to the steel casing (1) on the construction platform, each of the steel casing (1) corresponds to two of the movable seats (2), and the distance between the two movable seats (2) is adapted to the distance between the two crawlers of the rotary drilling rig; S2, driving the rotary drilling rig onto the movable base (2), so that the two movable bases (2) respectively support the two crawlers of the rotary drilling rig; S3, the rotary drilling rig drives its own drill rod to move downward into the steel casing (1), and moves the rotary drilling rig on the moving seat (2) until the drill rod and the steel casing (1) are coaxial; S4, the drill rod drives the drill bit downward through the steel casing (1) to reach the riverbed rock layer to drill the riverbed, the drill bit drills downward to the hole bottom elevation and removes the slag, and the removed slag is stored in a slag box; S5, replacing the rotary drilling rig, the distance between the two movable seats (2) can be adjusted, after the previous rotary drilling rig exits, the distance between the two movable seats (2) is adjusted to be compatible with the distance between the two crawlers of the next rotary drilling rig, and the drill bit size of the next rotary drilling rig is larger than the drill bit size of the previous rotary drilling rig; S6, repeating S2-S5 until the inner diameter of the expanded pore reaches a predetermined value of the pile foundation; In S3, a correction seat (5) is used to point the drill pipe, the correction seat (5) is located in the steel casing (1), the correction seat (5) has a cavity (6), and the correction seat (5) is hinged with a plurality of synchronously rotating pointing rods (7) at the cavity (6); When in use, the drill bit is passed downward through the cavity (6) so that the drill rod is opposite to the cavity (6), and then the pointing rod (7) is rotated into the cavity (6), and the rotary drilling rig is moved at the same time until the drill rod abuts against all the pointing rods (7) in the correction seat (5), so that the drill rod and the steel casing (1) are coaxially arranged; The correction seat (5) and the cavity (6) are coaxial with the steel casing (1), a plurality of the pointing rods (7) are evenly spaced on the correction seat (5), and the correction seat (5) is coaxially provided with a toothed ring (8) engaged with the hinged joints of all the pointing rods (7), and the correction seat (5) is also provided with an elastic member connected to the toothed ring (8), and the elastic member gives the toothed ring (8) a tendency to rotate, so as to drive the pointing rod (7) to rotate toward the cavity (6); The elastic member is a first spring (9), a first connecting portion (10) is provided in the correction seat (5), a second connecting portion (11) is provided on the outer wall of the gear ring (8), and the first spring (9) is connected between the first connecting portion (10) and the second connecting portion (11); The correction seat (5) is provided with a mounting cavity (12) connected to the second connecting portion (11), a first seat (13) is provided in the mounting cavity (12), a suction portion (14) for sucking the second connecting portion (11) is provided in the first seat (13) and moves up and down, and a second spring (15) is provided in the first seat (13) for driving the suction portion (14) to move downward, and a connecting rope (16) connected to the suction portion (14) is provided on the movable seat (2); In S3, before the drill bit passes through the cavity (6), the connecting rope (16) is wound to drive the suction part (14) to move upward, so that the suction part (14) moves upward to be opposite to the second connecting part (11), so that the second connecting part (11) is attracted by the suction part (14) and moves, so that the pointing rod (7) is rotated and stored in the direction of leaving the cavity (6), and then the drill bit is passed downward through the cavity (6); when the drill bit is located below the correction seat (5), the connecting rope (16) is unwound, so that the suction part (14) moves downward to be staggered with the second connecting part (11) under the drive of the second spring (15), and the second connecting part (11) drives the gear ring (8) to rotate under the action of the first spring (9), so that the pointing rod (7) rotates toward the center of the cavity (6).

2. The bridge super-large diameter pile foundation hole expansion construction process according to claim 1 is characterized by: In S1, a base (3) is built on the construction platform, the movable seat (2) slides on the base (3), and the base (3) has a driving member (4), and the driving member (4) is used to drive the two movable seats (2) to move toward or away from each other.

3. The bridge super-large diameter pile foundation hole expansion construction process according to claim 2 is characterized by: The driving member (4) includes a bidirectional screw (41) and a driving motor (42), wherein the bidirectional screw (41) is rotatably connected to the base (3), and the driving motor (42) is installed on the base (3) to drive the bidirectional screw (41) to rotate, and the bidirectional screw (41) has a positive rotation part (411) and a counter-rotation part (412) with opposite threads, and the two movable seats (2) are respectively threadedly connected to the positive rotation part (411) and the counter-rotation part (412).

4. The bridge super-large diameter pile foundation hole expansion construction process according to claim 1 is characterized by: The correction seat (5) slides up and down in the steel casing (1), and the correction seat (5) has a second seat (17) connected to the first seat (13) in the installation cavity (12), and the first seat (13) and the second seat (17) slide together in the installation cavity (12), and a magnetic strip (18) corresponding to the second seat (17) is embedded on the inner wall of the bottom of the steel casing (1), and the second seat (17) and the magnetic strip (18) repel each other; In S4, when the drill bit moves downward, the connecting rope (16) is unwound, so that the second seat (17) moves to the bottom of the steel casing (1), and the second seat (17) is repelled by the magnetic strip (18) and moves to be opposite to the second connecting portion (11). The second connecting portion (11) is attracted by the second seat (17) and moves away from the inner wall of the steel casing (1), so that the second seat (17) is opposite to the second connecting portion (11), and the first seat (13) is misaligned with the second connecting portion (11), so that the pointing rod (7) is stored in a direction away from the cavity (6).

5. The bridge super-large diameter pile foundation hole expansion construction process according to claim 1 is characterized by: A reel (19) for reeling and unreeling the connecting rope (16) is rotatably connected to the movable seat (2), and a power source (20) for driving the reel (19) to rotate is installed on the movable seat (2).

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