A construction process for drilling and planting precast pipe piles

Abstract

This invention discloses a construction process for drilling and planting precast pipe piles, relating to the field of pipe pile planting technology, including the following steps: connecting a first steel retaining column to a rotary drilling head, and using the rotary drilling head to rotate and apply downward pressure to vertically implant the first steel retaining column into the ground, with the implanted first steel retaining column protruding from the upper surface of the ground, and clamping the first steel retaining column with a bottom clamping mechanism; separating the first steel retaining column from the rotary drilling head, and connecting a second steel retaining column sequentially to the first steel retaining column and the rotary drilling head, then releasing the first steel retaining column with the bottom clamping mechanism, and using the rotary drilling head to rotate and apply downward pressure to implant the second steel retaining column and the first steel retaining column as a whole into the ground, forming a dry excavation hole; using lifting equipment to position the grouting conduit in the middle of the dry excavation hole: This solves the problem in the prior art that multiple countersunk bolts need to be installed and tightened on the two steel retaining columns, increasing the time required for installation and disassembly.

Description

Technical Field

[0001] This invention relates to the field of pipe pile installation technology, specifically a construction process for drilling and installing precast pipe piles. Background Technology

[0002] There are three existing methods for constructing pipe piles: hammer driving, implantation, and static pressure. Static pressure construction requires the use of a static pressure machine, which is relatively large and the pile driving position is located in the center of the machine, making it unsuitable for expansion construction. Hammer driving construction generates significant vibrations, which can affect residential buildings and prevent construction near bridges and villages. Therefore, implantation is required for construction in sections passing through villages.

[0003] Chinese invention patent CN109137915B proposes a dry excavation and implantation module structure for pile-slab roadbed and its construction method: the axial ends of two steel casings are detachably fixedly connected; both ends of the steel casings are stepped structures; the two upper and lower fixedly connected steel casings are fitted together by a step recessed on the outer side of the top of the lower steel casing and a step recessed on the inner side of the bottom of the upper steel casing, and countersunk bolts are also provided; the countersunk bolts pass radially through the corresponding through holes on the stepped connection structure of the two steel casings to achieve detachable fixed connection and limiting of the two steel casings; and multiple countersunk bolts are circumferentially arrayed on the stepped connection structure of the two steel casings.

[0004] The existing technology has the following drawbacks: multiple countersunk bolts are distributed in a circumferential array on the stepped connection structure of the two steel casings. Because multiple countersunk bolts need to be installed and tightened, the time required for the installation and disassembly process is increased. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a construction process for drilling and installing precast pipe piles, which solves the problem in the prior art that multiple countersunk bolts need to be installed and tightened on two steel casings, increasing the time required for installation and disassembly.

[0006] To achieve the above objectives, according to an embodiment of the first aspect of the present invention, a construction process for drilling and installing precast pipe piles is proposed, comprising the following steps:

[0007] S1: Connect the first steel support column to the rotary drilling power head. By rotating the rotary drilling power head and applying downward pressure, the first steel support column is vertically inserted into the ground, and the inserted first steel support column protrudes from the upper surface of the ground. The first steel support column is clamped by the bottom clamping mechanism.

[0008] S2: Separate the first steel support column from the rotary drilling head, connect the second steel support column to the first steel support column and the rotary drilling head in sequence, then the bottom clamping mechanism loosens the first steel support column, and by rotating the rotary drilling head and applying downward pressure, the second steel support column and the first steel support column are inserted into the soil as a whole to form a dry excavation hole;

[0009] S3: Use lifting equipment to position the grouting pipe in the middle of the dry excavation hole, and set the bottom outlet of the grouting pipe to correspond to the bottom of the dry excavation hole. The concrete grout is injected into the dry excavation hole through the top connection of the grouting pipe. After squeezing out the water in the dry excavation hole and filling the dry excavation hole, the grouting pipe is taken out.

[0010] S4: Connect the rotary drilling head to the pipe pile. By rotating the rotary drilling head and applying downward pressure, the pipe pile is vertically pressed into the concrete grout. The pipe pile protrudes from the upper surface of the soil and is clamped by the bottom clamping mechanism. Separate the rotary drilling head from the current pipe pile. Then connect the rotary drilling head to another pipe pile. The rotary drilling head drives the pipe pile to align axially with the embedded pipe pile. Weld the exposed steel bars of the two pipe piles to fix them. Screw the two fixedly connected pipe piles into the concrete grout and wait for it to solidify to complete the pipe pile implantation.

[0011] As a further embodiment of the present invention: the first steel guard post and the second steel guard post are detachably connected. The bottom end of the second steel guard post is fixedly connected to a fixed post. Limiting plates are symmetrically fixedly connected to both sides of the fixed post. Movable protrusions are symmetrically fixedly connected to the side of the fixed post. The side of the fixed post is symmetrically provided with first screw holes. A cavity is provided inside the fixed post. A first electric push rod is symmetrically fixedly installed inside the cavity. A motor is fixedly connected to the telescopic end of the first electric push rod. A locking bolt is fixedly connected to the output end of the motor. An installation groove is provided at the top of the first steel guard post. Connecting grooves are symmetrically provided on both sides of the installation groove. Limiting protrusions are fixedly connected inside the connecting groove and near the upper end. Second screw holes are symmetrically provided on the inner wall of the installation groove.

[0012] As a further embodiment of the present invention: the first steel support column, the second steel support column, and the pipe pile are all detachably connected to the rotary drilling power head. The first steel support column and the second steel support column are cylindrical structures. The rotary drilling power head is connected to a rotary drilling power device. The first steel support column and the second steel support column have the same height and the same cross-sectional radius. The cross-sectional radius of the first steel support column is larger than that of the pipe pile.

[0013] As a further aspect of the present invention: the first screw hole is located directly below the movable protrusion, the cavity is connected to the first screw holes on both sides, the mounting groove is cylindrical, and limit grooves are symmetrically opened on both sides of the mounting groove. The shape of the limit groove is adapted to the rotation trajectory of the limit plate, the shape of the connecting groove is adapted to the movement trajectory of the movable protrusion, and the second screw hole is located directly below the corresponding limit protrusion.

[0014] As a further embodiment of the present invention: a bottom clamping mechanism is symmetrically arranged at the upper end of the rotary soil. The bottom clamping mechanism includes a fixed plate, a rod connected to the bottom end of the fixed plate, a horizontal plate fixedly connected to the top end of the fixed plate, a long screw threadedly connected to the horizontal plate, the long screw penetrating the horizontal plate, an arc-shaped block rotatably connected to the end of the long screw, and mating rods threadedly connected to both sides of the long screw on the horizontal plate, the mating rods abutting against the arc-shaped blocks.

[0015] As a further aspect of the present invention: the top end of the second steel guard post is fixedly connected to a protrusion, and the bottom end of the rotary drilling power head is provided with a recess. The protrusion of the second steel guard post is adapted to the recess of the rotary drilling power head. The side wall of the rotary drilling power head and the protrusion of the second steel guard post are both provided with mutually matching threaded holes. The threaded holes on the rotary drilling power head are connected to the recess of the rotary drilling power head.

[0016] As a further aspect of the present invention: a pipe pile locking component is detachably installed on the rotary drilling power head. The pipe pile locking component includes a fixing ring with symmetrical mating holes. The shape of the fixing ring is adapted to the shape of the rotary drilling power head and the pipe pile. A cylinder is symmetrically fixedly connected to the fixing ring. The output end of the cylinder passes through the side wall of the fixing ring and is fixedly connected to a clamping block. The clamping block is arc-shaped and adapted to the pipe pile.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. Align the limiting plate with the limiting groove. During this process, the movable protrusion moves down along the connecting groove until the bottom of the fixed column is against the bottom of the mounting groove. Use external mechanical equipment to clamp the second steel guard column and rotate it clockwise by a certain angle. At the same time, the movable protrusion rotates clockwise by the same angle in the connecting groove until the limiting plate is against the inner wall of the limiting groove. At this time, the limiting protrusion is exactly above the movable protrusion. The limiting protrusion can restrict the position of the movable protrusion and prevent it from moving upward.

[0019] 2. When the second screw hole overlaps with the corresponding first screw hole, the first electric push rod and the motor are started simultaneously. The extension end of the first electric push rod drives the motor and the locking bolt to move in the direction of the corresponding second screw hole. The output end of the motor drives the locking bolt to rotate, so that the locking bolt passes through the corresponding first screw hole and the second screw hole in sequence, so that the fixing post is fixed in the mounting groove, and then the first steel guard post and the second steel guard post can be fixed quickly. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the second steel retaining column of the present invention;

[0022] Figure 3 This is an internal sectional view of the second steel retaining column of the present invention;

[0023] Figure 4 This is a partial structural schematic diagram of the first steel retaining column of the present invention;

[0024] Figure 5 This is an enlarged view of part A of the present invention;

[0025] Figure 6 This is a schematic diagram of the steel retaining column implantation structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the pipe pile implantation structure of the present invention;

[0027] Figure 8 This is a schematic diagram of the structure of the pipe pile locking component of the present invention.

[0028] In the diagram: 1. Land; 2. First steel support post; 21. Installation groove; 22. Limiting groove; 23. Connecting groove; 24. Limiting protrusion; 25. Second screw hole; 3. Second steel support post; 31. Fixed post; 32. Limiting plate; 33. Movable protrusion; 34. First screw hole; 35. Cavity; 4. Rotary drilling power head; 5. Rotary drilling power equipment; 6. First electric push rod; 7. Motor; 8. Locking bolt; 9. Fixed plate; 10. Horizontal plate; 11. Arc block; 12. Long screw rod; 13. Matching rod; 14. Pipe pile; 15. Pipe pile locking component; 151. Fixing ring; 152. Cylinder; 153. Clamping block; 154. Matching hole. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1-8 As shown, a construction process for drilling and planting precast pipe piles includes: a first steel support column 2, a second steel support column 3, a rotary drilling power head 4, and a pipe pile 14. The first steel support column 2 and the second steel support column 3 are cylindrical structures. The first steel support column 2 and the second steel support column 3 are detachably connected. The first steel support column 2, the second steel support column 3, and the pipe pile 14 are all detachably connected to the rotary drilling power head 4. The rotary drilling power head 4 is connected to a rotary drilling power device 5. The first steel support column 2 and the second steel support column 3 have the same height and the same cross-sectional radius. The cross-sectional radius of the first steel support column 2 is larger than the cross-sectional radius of the pipe pile 14.

[0031] The first steel support post 2 and the second steel support post 3 are driven to rotate by the rotary drilling head 4, and at the same time, the rotary drilling head 4 applies downward pressure to implant the first steel support post 2 and the second steel support post 3 into the soil 1.

[0032] The bottom end of the second steel guard post 3 is fixedly connected to a fixed post 31. Limiting plates 32 are symmetrically fixedly connected to both sides of the fixed post 31. Movable protrusions 33 are symmetrically fixedly connected to the side of the fixed post 31. The side of the fixed post 31 is symmetrically provided with first screw holes 34, which are located directly below the movable protrusions 33.

[0033] The fixed column 31 has a cavity 35 inside, and a first electric push rod 6 is symmetrically fixed inside the cavity 35. The telescopic end of the first electric push rod 6 is fixedly connected to a motor 7, and the output end of the motor 7 is fixedly connected to a locking bolt 8. The cavity 35 is connected to the first screw holes 34 on both sides, and the locking bolt 8 can pass through the corresponding first screw holes 34 and extend into the first steel guard column 2.

[0034] The top of the first steel guard post 2 is provided with an installation groove 21, which is cylindrical. The two sides of the installation groove 21 are symmetrically provided with limit grooves 22. The shape of the limit grooves 22 is adapted to the rotation trajectory of the limit plate 32. The two sides of the installation groove 21 are symmetrically provided with connecting grooves 23. The shape of the connecting grooves 23 is adapted to the movement trajectory of the movable protrusions 33. The limit protrusions 24 are fixedly connected inside the connecting grooves 23 and near the upper end. The inner wall of the installation groove 21 is symmetrically provided with second screw holes 25, which are located directly below the corresponding limit protrusions 24.

[0035] The specific method for detachably connecting the first steel guard post 2 and the second steel guard post 3 is as follows: Align the limiting plate 32 with the limiting groove 22. During this process, the movable protrusion 33 moves downwards along the connecting groove 23 until the bottom of the fixed post 31 is against the bottom of the mounting groove 21. Use external mechanical equipment to clamp the second steel guard post 3 and rotate it clockwise by a certain angle. Simultaneously, the movable protrusion 33 rotates clockwise by the same angle within the connecting groove 23 until the limiting plate 32 is against the inner wall of the limiting groove 22. At this point, the limiting protrusion 24 is directly above the movable protrusion 33, and the limiting protrusion 24 can... To restrict the position of the movable protrusion 33 and prevent it from moving upward, the second screw hole 25 overlaps with the corresponding first screw hole 34. At the same time, the first electric push rod 6 and the motor 7 are activated. The extension end of the first electric push rod 6 drives the motor 7 and the locking bolt 8 to move in the direction of the corresponding second screw hole 25. The output end of the motor 7 drives the locking bolt 8 to rotate, so that the locking bolt 8 passes through the corresponding first screw hole 34 and the second screw hole 25 in sequence, so that the fixing post 31 is fixed in the mounting groove 21, thereby realizing the fixing of the first steel guard post 2 and the second steel guard post 3.

[0036] A bottom clamping mechanism is symmetrically arranged at the upper end of the land 1. The bottom clamping mechanism realizes the relative clamping and loosening of the first steel retaining column 2 or pipe pile 14. The bottom clamping mechanism includes a fixing plate 9. The bottom end of the fixing plate 9 is connected to a plug rod. The fixing plate 9 is fixed by inserting the plug rod into the land 1. The top end of the fixing plate 9 is fixedly connected to a horizontal plate 10. A long screw 12 is threadedly connected to the horizontal plate 10. The long screw 12 passes through the horizontal plate 10. An arc block 11 is rotatably connected to the end of the long screw 12. Matching rods 13 are threadedly connected to both sides of the long screw 12 on the horizontal plate 10. The matching rods 13 abut against the arc block 11. The matching rods 13 can make the side of the arc block 11 fit against the first steel retaining column 2 or pipe pile 14. By rotating the long screw 12, the long screw 12 drives the arc-shaped block 11 to move closer to or further away from the first steel retaining column 2 or pipe pile 14, thereby achieving relative clamping and loosening of the first steel retaining column 2 or pipe pile 14.

[0037] The specific method for detachably connecting the rotary drilling power head 4 and the second steel support column 3 is as follows: The top of the second steel support column 3 is fixedly connected to a protrusion, and the bottom of the rotary drilling power head 4 is provided with a recess. The protrusion of the second steel support column 3 is adapted to the recess of the rotary drilling power head 4. The side wall of the rotary drilling power head 4 and the protrusion of the second steel support column 3 are both provided with mutually matching threaded holes. The threaded holes on the rotary drilling power head 4 are connected to the recess of the rotary drilling power head 4. The protrusion of the second steel support column 3 is engaged with the recess of the rotary drilling power head 4. A screw is used to pass through the threaded holes on the protrusions of the rotary drilling power head 4 and the second steel support column 3 in sequence, thereby fixing the rotary drilling power head 4 and the second steel support column 3 together.

[0038] A pipe pile locking component 15 is detachably installed on the rotary drilling power head 4. The pipe pile locking component 15 includes a fixing ring 151. The fixing ring 151 has symmetrical mating holes 154. The shape of the fixing ring 151 is adapted to the shape of the rotary drilling power head 4 and the pipe pile 14. A cylinder 152 is symmetrically fixedly connected to the fixing ring 151. The output end of the cylinder 152 passes through the side wall of the fixing ring 151 and is fixedly connected to a clamping block 153. The clamping block 153 is arc-shaped and is adapted to the pipe pile 14.

[0039] The specific method for detachably connecting the rotary drilling power head 4 and the pipe pile 14 is as follows: Place the fixing ring 151 onto the rotary drilling power head 4, aligning the mating hole 154 with the threaded hole of the rotary drilling power head 4. Use screws to pass through the mating hole 154 and the threaded hole of the rotary drilling power head 4 in sequence, thus fixing the fixing ring 151 onto the rotary drilling power head 4. Insert the top end of the pipe pile 14 into the fixing ring 151. Start the cylinder 152; the output end of the cylinder 152 drives the clamping block 153 to move towards the pipe pile 14, thereby fixing the rotary drilling power head 4 and the pipe pile 14.

[0040] Working principle:

[0041] S1: The first steel support column 2 is detachably connected to the rotary drilling power head 4, so that the first steel support column 2 and the rotary drilling power head 4 become a whole. By rotating the rotary drilling power head 4 and applying downward pressure, the first steel support column 2 is vertically inserted into the soil 1, and the inserted first steel support column 2 protrudes from the upper end surface of the soil 1. The first steel support column 2 is clamped by the bottom clamping mechanism.

[0042] S2: Separate the first steel support column 2 from the rotary drilling head 4, connect the second steel support column 3 to the first steel support column 2 and the rotary drilling head 4 in sequence, then the bottom clamping mechanism loosens the first steel support column 2, and by rotating the rotary drilling head 4 and applying downward pressure, the second steel support column 3 and the first steel support column 2 are inserted into the soil 1 as a whole to form a dry excavation hole;

[0043] S3: Use lifting equipment to position the grouting pipe in the middle of the dry excavation hole, and set the bottom outlet of the grouting pipe to correspond to the bottom of the dry excavation hole. The concrete grout is injected into the dry excavation hole through the top connection of the grouting pipe. After squeezing out the water in the dry excavation hole and filling the dry excavation hole, the grouting pipe is taken out.

[0044] S4: Connect the rotary drilling head 4 to the pipe pile 14. By rotating the rotary drilling head 4 and applying downward pressure, the pipe pile 14 is vertically pressed into the concrete grout. The pipe pile 14 protrudes from the upper end of the soil 1 and is clamped by the bottom clamping mechanism. The rotary drilling head 4 is then separated from the current pipe pile 14. Next, the rotary drilling head 4 is connected to another pipe pile 14. The rotary drilling head 4 drives the pipe pile 14 to align axially with the embedded pipe pile 14. The exposed steel bars of the two pipe piles 14 are welded and fixed. The two fixedly connected pipe piles 14 are then screwed into the concrete grout. The installation of the pipe pile 14 is completed by waiting for it to solidify.

[0045] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A construction process for drilling and planting precast pipe piles, characterized in that, The method comprises the following steps: S1: connecting the first steel guard column (2) with the rotary digging power head (4), rotating and applying downward pressure through the rotary digging power head (4) to realize vertical planting of the first steel guard column (2) in the land (1), and the planted first steel guard column (2) protrudes from the upper end surface of the land (1), and the first steel guard column (2) is clamped through the bottom clamping mechanism; S2: disconnecting the first steel guard column (2) from the rotary digging power head (4), connecting the second steel guard column (3) with the first steel guard column (2) and the rotary digging power head (4) in turn, then loosening the first steel guard column (2) by the bottom clamping mechanism, rotating and applying downward pressure through the rotary digging power head (4) to plant the second steel guard column (3) and the first steel guard column (2) integrally in the land (1) to form a dry excavation hole; S3: positioning and placing the grouting pipe in the middle of the dry excavation hole using a hoisting device, and the bottom grouting outlet of the grouting pipe is correspondingly arranged at the bottom of the dry excavation hole, and the concrete slurry is injected into the dry excavation hole through the top connecting port of the grouting pipe, and after the water in the dry excavation hole is squeezed out and the dry excavation hole is filled, the grouting pipe is removed; S4: connecting the rotary digging power head (4) with the pipe pile (14), rotating and applying downward pressure through the rotary digging power head (4) to realize vertical planting of the pipe pile (14) in the concrete slurry, the pipe pile (14) protruding from the upper end surface of the land (1), and the pipe pile (14) being clamped through the bottom clamping mechanism, separating the rotary digging power head (4) from the current pipe pile (14), then connecting the rotary digging power head (4) with another pipe pile (14), the rotary digging power head (4) driving the pipe pile (14) to axially correspond to the buried pipe pile (14), welding and fixing the two opposite exposed steels of the two pipe piles (14), rotating the two fixedly connected pipe piles (14) into the concrete slurry, and waiting for solidification to realize planting of the pipe pile (14); The first steel guard column (2) and the second steel guard column (3) are detachably connected, the bottom end of the second steel guard column (3) is fixedly connected with a fixed column (31), the two sides of the fixed column (31) are symmetrically fixedly connected with limiting plates (32), the side surface of the fixed column (31) is symmetrically fixedly connected with movable convex particles (33), the side surface of the fixed column (31) is symmetrically provided with first screw holes (34), the inside of the fixed column (31) is provided with a cavity (35), the inside of the cavity (35) is symmetrically fixedly provided with first electric push rods (6), the extension end of the first electric push rod (6) is fixedly connected with a motor (7), the output end of the motor (7) is fixedly connected with a locking bolt (8), the top end of the first steel guard column (2) is provided with a mounting groove (21), the two sides of the mounting groove (21) are symmetrically provided with connecting grooves (23), the inside of the connecting groove (23) and close to the upper end are fixedly connected with limiting convex particles (24), and the inner wall of the mounting groove (21) is symmetrically provided with second screw holes (25). The first steel guard column (2), the second steel guard column (3) and the pipe pile (14) are detachably connected with the rotary digging power head (4), the first steel guard column (2) and the second steel guard column (3) are in cylindrical structure, the rotary digging power head (4) is connected with a rotary digging power device (5), the height and the cross-sectional radius of the first steel guard column (2) and the second steel guard column (3) are the same, the cross-sectional radius of the first steel guard column (2) is greater than the cross-sectional radius of the pipe pile (14); The first screw hole (34) is directly below the movable convex particle (33), the cavity (35) is in communication with the first screw holes (34) on both sides, the mounting groove (21) is in cylindrical shape, the limit grooves (22) are symmetrically arranged on both sides of the mounting groove (21), the shape of the limit grooves (22) is adapted to the rotating track of the limit plate (32), the shape of the connecting groove (23) is adapted to the movement track of the movable convex particle (33), and the second screw hole (25) is directly below the corresponding limit convex particle (24).

2. The construction process of precast pipe pile by drilling pile planting according to claim 1, characterized in that, The bottom clamping mechanism is symmetrically arranged at the upper end of the land (1), and comprises a fixed plate (9), a plug rod (12) is connected to the bottom end of the fixed plate (9), a horizontal plate (10) is fixedly connected to the top end of the fixed plate (9), a long screw rod (12) is threadedly connected to the horizontal plate (10), the long screw rod (12) penetrates through the horizontal plate (10), an arc-shaped block (11) is rotatably connected to the end of the long screw rod (12), and a matching rod (13) is threadedly connected to the positions on both sides of the long screw rod (12) on the horizontal plate (10). The matching rod (13) abuts against the arc-shaped block (11).

3. The construction process for precast pipe pile by boring and planting pile according to claim 1, characterized in that, The top end of the second steel guard column (3) is fixedly connected with a protruding portion, the bottom end of the rotary digging power head (4) is provided with a recessed portion, the protruding portion of the second steel guard column (3) is matched with the recessed portion of the rotary digging power head (4), and the side wall of the rotary digging power head (4) and the protruding portion of the second steel guard column (3) are both provided with thread holes matched with each other.

4. The construction process for precast pipe pile by boring and planting pile as claimed in claim 1, wherein, The pipe pile locking piece (15) is detachably installed on the rotary digging power head (4), the pipe pile locking piece (15) comprises a fixed ring (151), the fixed ring (151) is symmetrically provided with a matching hole (154), the shape of the fixed ring (151) is matched with the shapes of the rotary digging power head (4) and the pipe pile (14), the fixed ring (151) is symmetrically fixedly connected with a gas cylinder (152), the output end of the gas cylinder (152) penetrates through the side wall of the fixed ring (151) and is fixedly connected with a clamping block (153), the clamping block (153) is arc-shaped and matched with the pipe pile (14).

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