Prestressed concrete pipe pile cement soil cushion layer composite foundation construction equipment and construction method

Abstract

The invention discloses prestressed concrete pipe pile cement soil cushion composite foundation construction equipment and a construction method, and relates to the technical field of foundation construction, the construction equipment is provided with a static pressure platform, and the top end of the static pressure platform is provided with a plurality of hydraulic jacks used for providing pressing power and lifting power of the static pressure platform; the bottom end of the static pressure platform is provided with a soil taking shutter basket used for containing soil excavated by the blades. A plurality of blades which are linearly arranged and are used for digging a soil body of a cushion layer are arranged at the bottom of the soil sampling shutter basket; a pile head ring used for penetrating through the prestressed concrete thin-wall pipe pile is arranged in the center of the bottom of the soil sampling shutter basket. And a hydraulic traction device for driving the blades to rotate is arranged at the top end of the soil sampling shutter basket. The surrounding soil body can be taken out at a time and serves as a formwork for pouring cement concrete, and the construction efficiency of the prestressed concrete pipe pile is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation construction, and more specifically, to a construction equipment and construction method for a composite foundation of a prestressed concrete pipe pile and a cement soil cushion. Background Technique

[0002] With the rapid development of infrastructure construction in China, foundation treatment technology plays an increasingly important role in engineering construction. Especially in foundations with insufficient bearing capacity such as soft soil foundations and filled soil foundations, the use of composite foundation technology can not only improve the bearing capacity of the foundation, but also effectively control post-construction settlement. Among many foundation treatment methods, the cement-soil mixing pile has been widely used in engineering practice due to its relatively low project cost. However, the cement-soil mixing pile has technical defects such as difficult control of pile formation quality, large discreteness of pile body strength, and low bearing capacity. These problems seriously restrict its application in important projects and also bring potential safety hazards to engineering construction.

[0003] The composite foundation of a prestressed concrete pipe pile and a cement soil cushion is a new type of foundation treatment technology, and its core lies in the organic combination of prestressed concrete pipe piles and cement soil cushions. The prestressed concrete pipe pile composite foundation has significant advantages such as good reinforcement effect, fast construction speed, and reliable reinforcement quality. Its pile body quality is stable and the bearing capacity is high, which can meet the construction requirements of important projects. However, since its cushion material usually uses gravel, the project cost is relatively high, which to a certain extent limits its large-scale application in engineering. Currently, it is only applied in areas with a high filling height or a thick soft soil covering layer.

[0004] However, during the construction process of the composite foundation of a prestressed concrete pipe pile and a cement soil cushion, there are still many technical problems in the pile cap construction link. The traditional pile cap construction method mainly relies on manual excavation and cleaning of the soil at the pile position, which not only has a large labor intensity and low construction efficiency, but also easily causes soil disturbance and affects the construction quality of the pile cap. At the same time, due to the lack of special construction equipment, problems such as concrete leaking into the pipe pile cavity and inaccurate control of the pile cap elevation often occur during the pile cap concrete pouring process. These problems not only reduce the construction efficiency, but also may affect the overall performance of the composite foundation.

[0005] In response to the problems in the related technology, no effective solution has been proposed yet. Summary of the Invention

[0006] In response to the problems in the related technology, the present invention proposes a construction equipment and construction method for a composite foundation of a prestressed concrete pipe pile and a cement soil cushion, which has the advantages of one-time soil taking and forming, high automation degree, and convenient construction, thereby solving the problems of low efficiency of manual soil excavation, cumbersome installation and disassembly of templates, and high construction cost in the prior art.

[0007] To this end, the specific technical solution adopted by the present invention is as follows:

[0008] According to one aspect of the present invention, there is provided a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement soil cushion. The construction equipment for the composite foundation of the prestressed concrete pipe pile and the cement soil cushion includes a static pressure platform. A number of hydraulic jacks for providing the downward pressure power and the lifting power of the static pressure platform are arranged at the top of the static pressure platform; a soil collection louver basket for containing the soil dug by the blades is arranged at the bottom of the static pressure platform; a number of blades for digging the soil of the cushion and arranged in a linear arrangement are arranged at the bottom of the soil collection louver basket; a pile head ring for passing through the pile head of the prestressed concrete thin-walled pipe pile is arranged at the center position of the bottom of the soil collection louver basket; a hydraulic traction device for driving the blades to rotate is arranged at the top of the soil collection louver basket.

[0009] Furthermore, the soil collection louver basket is arranged in a box-shaped structure. The height of the box-shaped structure is less than the width. Closed steel plates are arranged on the peripheral side walls of the box-shaped structure. A number of cross braces are arranged in the middle of the box-shaped structure. The cross braces are vertically and crosswise arranged with the blades, and both sides of the pile head ring are fixedly connected with the cross braces.

[0010] Furthermore, the blades are arranged in a sheet-shaped conical structure. The sheet-shaped conical structure is wider at the top and narrower at the bottom in the vertical direction and can rotate within a range of 180°; the top of the blade is hinged to the bottom of the soil collection louver basket, and a wire passing hole is opened at the bottom of the blade.

[0011] Furthermore, the pile head ring is arranged in a circular ring structure. The inner diameter of the pile head ring is larger than the outer diameter of the prestressed concrete thin-walled pipe pile; a sealing chassis is arranged at the bottom of the pile head ring. A number of hooks arranged in a circumferential arrangement are fixedly arranged at the top of the sealing chassis. The hooks are detachably suspended and connected with the pile head ring.

[0012] Furthermore, the hydraulic traction device includes a number of groups of hydraulic power devices symmetrically arranged at the top of the soil collection louver basket, a traction rope and a hinge joint; wherein, each group of hydraulic power devices includes two relatively arranged hydraulic cylinders. The two ends of the traction rope are respectively connected with the output ends of the two hydraulic cylinders. The middle of the bottom end of the traction rope passes through the wire passing hole of the blade. The hinge joint is arranged at the connection part between the blade and the soil collection louver basket; the two hydraulic cylinders repeatedly change the traction direction according to the traction force magnitude to drive the blade to rotate to a completely horizontal state.

[0013] According to another aspect of the present invention, there is also provided a construction method for a composite foundation of a prestressed concrete pipe pile and a cement soil cushion. The construction method includes:

[0014] S1. Level the site, measure and set out the lines, and mark the pile positions of the pipe piles;

[0015] S2. Based on the marked pile positions, select the first pile driving mode or the second pile driving mode to complete the pipe pile construction according to the bearing capacity of the foundation, and mark the pile cap positions;

[0016] S3. Fabricate the pile cap. Control the rotation of the blade 3 through the hydraulic traction device 5, and cooperate with the soil-taking louver basket 2 to complete the excavation and cleaning of the soil body.

[0017] S4. Compact the soil-taking pit through the static pressure platform 1, place the steel bar cage of the pipe pile cap, place the sealing chassis 6 in the cavity of the pipe pile, hang the hook on the steel bar cage, and pour concrete to the designed thickness.

[0018] S5. Move the equipment to the next pile position. After all the pile bodies are constructed, lay the geogrid and the cement soil cushion layer, and roll them to the designed compaction degree to complete the construction of the composite foundation.

[0019] Furthermore, level the site, measure and set out the lines, and mark the pipe pile positions, including leveling the site according to the elevation characteristics of the site and establishing an adaptive dynamic pile position compensation algorithm based on the soil body deformation parameters to realize the measurement, setting out the lines and marking of the pipe pile positions. Specifically, it includes:

[0020] S11. Select the corresponding leveling mode to level the site according to the relationship between the surface elevation and the designed elevation of the pile top.

[0021] S12. Based on the three-dimensional laser point cloud technology and the soil body deformation parameters, establish an adaptive dynamic pile position compensation algorithm, and realize the measurement and setting out of the lines through iterative optimization.

[0022] S13. Mark the pipe pile positions according to the results of the measurement and setting out of the lines.

[0023] Among them, the elevation characteristics of the site include the surface elevation and the designed elevation of the pile top; the soil body deformation parameters include the slope angle parameter, the dynamic correction coefficient and the coordinate compensation amount; the coordinate compensation amount includes the horizontal direction compensation amount and the vertical direction compensation amount.

[0024] Furthermore, S11 includes:

[0025] When the surface elevation is greater than the pile top elevation, excavate the over-high part and level the site elevation to the designed elevation of the pile top.

[0026] When the surface elevation is equal to the pile top elevation, level it directly.

[0027] When the surface elevation is less than the pile top elevation, backfill and compact it to the designed elevation and compact and level it.

[0028] S12 includes:

[0029] Generate a digital elevation model of the site using the three-dimensional laser point cloud to obtain the slope angle parameter.

[0030] Based on the slope angle parameter, consider the influence of soil body deformation on the compensation amount and establish a dynamic correction coefficient.

[0031] Calculate the compensation amounts in the horizontal and vertical directions according to the dynamic correction coefficient to obtain the coordinate compensation amount;

[0032] Verify the pile position error through the measured pile position compensation amount and the predicted pile position compensation amount, and iteratively optimize the dynamic correction coefficient until the pile position error reaches the preset threshold, and then carry out measurement and setting out.

[0033] Furthermore, the expression of the dynamic correction coefficient is:

[0034]

[0035] The expression of the coordinate compensation amount is:

[0036]

[0037] The expression of the pile position error is:

[0038]

[0039] In the formula, θ x 、θ y 、θ z are the slope angles in the X, Y, and Z directions respectively; k x and k y are the dynamic correction coefficients in the X direction and the Y direction respectively; ΔX, ΔY, and ΔZ are the pile position compensation amounts in the X, Y, and Z directions respectively; E is the measured value of the soil compression modulus; v is the soil Poisson's ratio; L p is the slope length; α is the slope direction azimuth angle; ε is the pile position error; ΔX 实测 and ΔY 实测 are the measured pile position compensation amounts in the X direction and the Y direction respectively; ΔX 计算 and ΔY 计算 are the predicted pile position compensation amounts in the X direction and the Y direction respectively.

[0040] Furthermore, the first pile driving mode is applicable to the foundation with the natural foundation bearing capacity less than the preset value, including:

[0041] When using static pile pressing, the pile sinking speed is controlled in two stages;

[0042] When using the hammering method, select the corresponding hammer weight and hammer distance according to the pile diameter, and control the total number of hammer blows and the number of hammer blows per unit depth at the end based on the pile body concrete strength;

[0043] The second pile driving mode is applicable to the foundation with the natural foundation bearing capacity greater than or equal to the preset value, including:

[0044] When using static pile pressing, the pile sinking speed is controlled in three stages;

[0045] When the hammering method is adopted, select the corresponding hammer weight and hammer distance according to the pile diameter, and control the total number of hammer blows and the number of hammer blows per unit depth of the last stage based on the concrete strength of the pile body;

[0046] When pile sinking is difficult, use a spiral drill rod to drill holes or the water jet vibroflotation method to assist in pile sinking.

[0047] The beneficial effects of the present invention are as follows:

[0048] (1) Through the cooperation of the soil-taking louver basket and the hydraulic traction device, the construction equipment of the present invention can take out the soil at the pile cap position at one time, and use the formed soil pit as a natural formwork for pouring concrete, which is convenient and fast, greatly improves the construction efficiency, reduces the project cost, and eliminates the cumbersome procedures of formwork installation and disassembly in traditional construction; at the same time, through the compaction effect of the static pressure platform, the stability of the soil pit wall surface is ensured, providing reliable forming conditions for pile cap pouring and significantly improving the construction efficiency.

[0049] (2) The construction equipment and method provided by the present invention can use the formed soil pit to replace the formwork for pouring the concrete pile cap of the pipe pile, greatly improving the construction efficiency of the prestressed concrete pipe pile; in addition, the present invention uses a cement soil cushion to replace the traditional gravel cushion, and combines the laying of geogrid to form a composite structure with high stiffness, greatly reducing the construction cost, reducing the project cost by more than 20%, and the cement soil cushion has a large stiffness, which is more conducive to giving full play to the pile body bearing capacity of the prestressed concrete pipe pile.

[0050] (3) By establishing an adaptive dynamic pile position compensation algorithm based on 3D laser point cloud technology and soil deformation parameters, the present invention realizes the precise positioning of the pile position; through the iterative optimization of the measured pile position compensation amount and the predicted pile position compensation amount, the adaptive dynamic pile position compensation algorithm effectively controls the pile position error, ensures the positioning accuracy of pipe pile construction, and provides a reliable guarantee for the subsequent construction quality.

[0051] (4) The present invention sets two pile driving modes according to the bearing capacity of the foundation, adopts a sectional control of the pile sinking speed for different depths, and provides auxiliary pile sinking measures such as spiral drill rod drilling and water jet vibroflotation method. This classification construction plan effectively solves the pile sinking problems under different foundation conditions and improves the construction adaptability and efficiency. Description of the Drawings

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0053] Figure 1It is a top view of a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0054] Figure 2 It is a side view of a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0055] Figure 3 It is a side view of a hydraulic traction device in a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0056] Figure 4 It is a side view of a pipe pile cavity plugging device in a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0057] Figure 5 It is a top view of a pipe pile cavity plugging device in a construction equipment for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0058] Figure 6 It is a flow chart of a construction method for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention;

[0059] Figure 7 It is a specific implementation diagram of a construction method for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion according to an embodiment of the present invention.

[0060] In the figure:

[0061] 1, static pressure platform; 2, soil-taking louver basket; 3, blade; 4, pile head ring; 5, hydraulic traction device; 51, hydraulic power device; 52, traction rope; 53, hinge joint; 6, plugging chassis; 7, hook; 8, hydraulic jack. Detailed implementation manners

[0062] To further illustrate each embodiment, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0063] According to an embodiment of the present invention, a construction equipment and a construction method for a composite foundation of a prestressed concrete pipe pile and a cement-soil cushion are provided.

[0064] Now, the present invention will be further described in conjunction with the accompanying drawings and specific implementation manners, as Figures 1 - 5As shown, according to an embodiment of the present invention, a construction equipment for a composite foundation of a prestressed concrete pipe pile cement soil cushion is provided. The construction equipment for the composite foundation of the prestressed concrete pipe pile cement soil cushion includes a static pressure platform 1. Hydraulic jacks 8 are arranged at the four corners of the top end of the static pressure platform 1. A soil-taking louver basket 2 is arranged at the bottom end of the static pressure platform 1. A number of blades 3 arranged linearly are provided at the bottom of the soil-taking louver basket 2. A pile head ring 4 is arranged at the center position of the bottom of the soil-taking louver basket 2. A hydraulic traction device 5 is arranged at the top end of the soil-taking louver basket 2.

[0065] Among them, the hydraulic jacks 8 are used to provide the downward pressure and lifting power of the static pressure platform 1. The soil-taking louver basket 2 is used to hold the soil dug by the blades 3. The blades 3 are used to dig the soil of the cushion. The pile head ring 4 is used to pass through the prestressed concrete thin-walled pipe pile. The hydraulic traction device 5 is used to drive the blades 3 to rotate.

[0066] Specifically, this construction equipment includes a static pressure platform 1 and a soil-taking louver basket 2 connected to the static pressure platform 1. The static pressure platform 1 is provided with hydraulic jacks 8. Blades 3 are arranged at the bottom of the soil-taking louver basket 2 and are connected to the pile head ring 4. The blades 3 can rotate within a range of 180°. The pile head ring 4 is a cavity body, and the pile head ring 4 can pass through the protruding pile head. A hydraulic traction device 5 is arranged on the upper part of the soil-taking louver basket 2. The hydraulic traction device 5 includes a hydraulic power device 51, a traction rope 52 and a hinge joint 53. The hydraulic power device 51, the traction rope 52 and the hinge joint 53 can cooperate with each other. The plugging chassis 6 is connected to the hook 7.

[0067] Specifically, the pile head ring 4 is a circular empty position for passing through the prestressed concrete thin-walled pipe pile because the soil at the pile head position of the pipe pile needs to be dug out.

[0068] Specifically, during the process of pouring the pile cap, a plugging chassis 6 and a hook 7 are adopted. After the hook 7 is connected to the plugging chassis 6, the hook 7 can be hung on the pile head ring 4.

[0069] Specifically, the static pressure platform 1 is provided with hydraulic jacks 8. In this embodiment, the hydraulic jacks 8 can provide a pressure of 70 to 100 kN.

[0070] In one embodiment, the soil-taking louver basket 2 is arranged in a box-shaped structure. The height of the box-shaped structure is less than the width. Closed steel plates are arranged on the four side walls of the box-shaped structure. A number of cross braces are arranged in the middle of the box-shaped structure. The cross braces are vertically and crosswise arranged with the blades 3, and both sides of the pile head ring 4 are fixedly connected to the cross braces.

[0071] Specifically, in the present embodiment, the height of the soil sampling louver basket 2 is set to 25 to 35 cm, the width is set to 100 cm to 160 cm, the four sides are closed steel plates, and cross braces are arranged in the middle, all of which are rigidly connected. Blades 3 are arranged at the bottom, and a pile head ring 4 is arranged at the central position.

[0072] Specifically, Figure 1 The thickened lines in the figure are cross braces (stiffening ribs), which are fixed to the pile head ring 4 by welding; the soil sampling louver basket 2 is also fixed to the blades 3 and the pile head ring 4 by welding.

[0073] In one embodiment, the blades 3 are arranged in a sheet-like conical structure, the sheet-like conical structure is wider at the top and narrower at the bottom in the vertical direction, and can rotate within a range of 180°; the top of the blades 3 is hinged to the bottom of the soil sampling louver basket 2, and a wire passing hole is provided at the bottom of the blades 3.

[0074] Specifically, the blades 3 are connected to the bottom of the soil sampling louver basket 2 by a hinged manner, the blades 3 can rotate within a range of 180°, the blades 3 are conical bodies, and the lower part of the conical blade 3 is connected to the hydraulic traction device 5.

[0075] Specifically, the blades 3 are sheet-like, and on the premise of being sheet-like, they are also in a conical structure, and the conical structure is in the form of a conical structure that is wider at the top and narrower at the bottom in the vertical direction.

[0076] Specifically, the lower part of the blades 3 is connected to the hydraulic traction device 5 by traction of a traction rope 52 (steel wire rope). When the blades 3 are in a vertical state, there is a small hole at the bottom, and the steel wire rope passes through the small hole and winds around once, then the blades 3 can be driven to rotate.

[0077] In one embodiment, the pile head ring 4 is arranged in a circular ring structure, the inner diameter of the pile head ring 4 is larger than the outer diameter of the prestressed concrete thin-walled pipe pile; a sealing chassis 6 is arranged at the bottom of the pile head ring 4, and a plurality of hooks 7 arranged in a circumferential manner are fixedly arranged at the top of the sealing chassis 6, and the hooks 7 are detachably suspended and connected to the pile head ring 4.

[0078] Specifically, in the present embodiment, the diameter of the pile head ring 4 is set to 32 cm to 62 cm.

[0079] Specifically, in the above embodiment, the sealing chassis 6 is connected to the hooks 7, the diameter of the sealing chassis 6 is set to 28 to 58 cm, and the length of the hooks 7 is set to 25 to 35 cm.

[0080] In one embodiment, the hydraulic traction device 5 includes several groups of hydraulic power devices 51, traction ropes 52, and hinge joints 53 symmetrically arranged at the top end of the soil-taking louver basket 2. Among them, each group of hydraulic power devices 51 includes two relatively arranged hydraulic cylinders. The two ends of the traction rope 52 are respectively connected to the output ends of the two hydraulic cylinders. The middle part of the bottom end of the traction rope 52 passes through the wire threading hole of the blade 3, and the hinge joint 53 is arranged at the connection between the blade 3 and the soil-taking louver basket 2. The two hydraulic cylinders repeatedly change the traction direction according to the traction force magnitude to drive the blade 3 to rotate to a completely horizontal position.

[0081] Specifically, the hydraulic traction device 5 includes a hydraulic power device 51, a traction rope 52, and a hinge joint 53. The hydraulic power device 51 is connected to the traction rope 52. The traction rope 52 is connected to the end of the conical blade 3. The blade 3 and the bottom of the soil-taking louver basket 2 are connected through the hinge joint 53.

[0082] The working principle of this construction equipment is as follows: Hydraulic jacks 8 provided at the four corners of the top end of the static pressure platform 1 provide a pressure of 70 to 100 kN to press the soil-taking louver basket 2 into the foundation soil. The soil-taking louver basket 2 is a box-shaped structure with a height of 25 to 35 cm and a width of 100 cm to 160 cm. The blades 3 provided at its bottom are in a vertical state with respect to the ground in the initial state. The blade 3 is a sheet-shaped conical structure that is wider at the top and narrower at the bottom and is connected to the bottom of the soil-taking louver basket 2 through the hinge joint 53. When the soil-taking louver basket 2 is pressed into the foundation soil, the hydraulic power device 51 of the hydraulic traction device 5 drives the blade 3 to rotate within a range of 180° to a horizontal state through the traction rope 52, realizing soil excavation. The pile head ring 4 (inner diameter 32 cm to 62 cm) provided in the middle of the soil-taking louver basket 2 is used to pass through the prestressed concrete pipe pile to ensure the effective excavation of the soil at the pile head position. After the excavation is completed, the hydraulic jack 8 lifts the static pressure platform 1 to take out the soil, and a plugging chassis 6 (diameter 28 to 58 cm) is installed at the pile head ring 4 and is suspended and fixed through a hook 7 with a length of 25 to 35 cm to prepare for the subsequent casting of the pile cap.

[0083] As Figures 6 - 7 shown, according to another embodiment of the present invention, there is also provided a construction method for a composite foundation of a prestressed concrete pipe pile and a cement soil cushion, and this construction method includes:

[0084] S1. Level the site, measure and set out the lines, and mark the pile positions of the pipe piles;

[0085] S2. Based on the marked pile positions, select the first or second pile driving mode according to the foundation bearing capacity to complete the pipe pile construction, and mark the pile cap positions;

[0086] S3. Manufacture the pile caps, control the rotation of the blade 3 through the hydraulic traction device 5, and cooperate with the soil-taking louver basket 2 to complete the soil excavation and cleaning;

[0087] S4. Compact the soil excavation pit through the static pressure platform 1, place the steel reinforcement cage of the pipe pile cap, place the sealing chassis 6 in the cavity of the pipe pile, hang the hook 7 on the steel reinforcement cage, and pour concrete to the designed thickness.

[0088] S5. Move the equipment to the next pile position. After all pile bodies are constructed, lay the geogrid and the cement soil cushion layer, and roll them to the designed compaction degree to complete the construction of the composite foundation.

[0089] Among them, S3 includes:

[0090] S31. Fabricate the pile cap, start the hydraulic traction device 5, and adjust the blade 3 to the direction perpendicular to the ground.

[0091] S32. Press the soil extraction louver basket 2 and the blade 3 into the foundation soil through the hydraulic jack 8, and put the pile head ring 4 on the pile head of the pipe pile.

[0092] S33. Start the hydraulic traction device 5, control the blade 3 to rotate to the direction parallel to the ground, and excavate the soil.

[0093] S34. Lift the soil extraction louver basket 2 through the hydraulic jack 8, clean up the loose soil and dump the soil.

[0094] Specifically, this construction method includes:

[0095] ① After the site is leveled, measure and set out the lines, and mark the positions of the pipe piles.

[0096] ② The pile driver is in place, drive the piles according to the marked pile positions, complete the construction of the pipe piles, and mark the positions of the pile caps.

[0097] ③ Fabricate the pile cap, start the hydraulic traction device 5, and adjust the bottom blade 3 of the soil extraction louver basket 2 to the direction perpendicular to the ground.

[0098] ④ Press the soil extraction louver basket 2 together with the blade 3 into the foundation soil through the hydraulic jack 8 set on the static pressure platform 1, stop when reaching the required depth of the pile cap, and put the pile head ring 4 on the pile head of the pipe pile.

[0099] ⑤ Start the hydraulic traction device 5, the hydraulic power device 51 drives the traction rope 52, the traction rope 52 drives the blade 3 to rotate, and the blade 3 changes from the direction perpendicular to the ground to the direction parallel to the ground.

[0100] Specifically, there are small holes at the bottom position of the blade 3 in the vertical state, and the traction rope 52 passes through the small holes and winds around once to drive the blade 3 to rotate.

[0101] Specifically, the hydraulic traction device 5 drives the blade 3 to rotate. In the present invention, controlling the moving direction and speed of the traction rope 52 driven by the hydraulic traction device 5, starting the hydraulic traction device 5, driving the blade 3 to rotate, and implementing speed grading steering control includes:

[0102] a) Initial stage (the angle between the blade 3 and the bottom surface of the soil sampling shutter basket 2 in the vertical direction ranges from 0° to 30°), rotate at a low speed of 1 - 2° / s. After the traction force is greater than 30 kN, switch the traction direction and pull in the reverse direction. When the reverse traction force is greater than 30 kN, switch the traction direction again, and so on.

[0103] b) Lifting stage (the angle between the blade 3 and the bottom surface of the soil sampling shutter basket 2 in the vertical direction ranges from 30° to 90°), rotate at a high speed of 3 - 6° / s. After the traction force is greater than 30 kN, switch the traction direction and pull in the reverse direction. When the reverse traction force is greater than 30 kN, switch the traction direction again, and so on. Until the blade 3 is completely horizontal.

[0104] It should be noted that the rotational speed grading steering control in the present invention is inspired by the principle of fishing: the fishing rod is like the hydraulic traction device 5, the fishing line is like the traction rope 52, and the blade 3 is like the fishhook. When fishing, the fishing line is wound around the fishhook, and the fishhook will rotate when pulling the line. However, when a fish bites the hook, one cannot keep pulling hard. One needs to loosen and tighten intermittently so that the fish will not escape. Similarly, when the blade 3 starts to dig the soil, the rope pulls the blade 3 to rotate. When a lot of soil is dug (more than 30 kN), continuing to pull may damage the equipment. At this time, one needs to relax slightly (switch the traction direction). However, because the soil is heavy, the blade 3 will not really turn back. By repeating "loosen - tighten - loosen - tighten" in this way, the equipment can be protected and the excavated soil mass will not fall off. This process of repeatedly switching the traction direction is actually a kind of "advance - retreat adjustment" mechanism: when advancing, it digs the soil and bears the load; when retreating, it stabilizes the soil mass and prevents overload, similar to the action of an excavator "shaking" the bucket. This way can make the soil mass stack stably on the blade 3 and release excessive stress to prevent equipment damage.

[0105] ⑥ Recover the hydraulic jack 8, lift out the soil sampling shutter basket 2, clean the loose soil, and pour out the soil mass taken out by the soil sampling shutter basket 2;

[0106] ⑦ Start the static pressure platform 1, compact the soil at the bottom and around the soil sampling pit, place the steel reinforcement cage of the pipe pile cap, place the sealing chassis 6 in the cavity of the pipe pile, hang the hook 7 on the steel reinforcement cage, and pour concrete to the designed thickness;

[0107] Specifically, the main purpose of this construction equipment is to realize the rapid construction of the pipe pile cap. The steel reinforcement cage is the steel reinforcement cage of the pipe pile cap, which is placed at the position after the soil is sampled by the soil sampling shutter basket 2. After hanging the sealing chassis 6, concrete can be poured to form the pile cap.

[0108] Specifically, the prestressed concrete thin-walled pipe pile itself is a precast reinforced concrete pile. During construction, it is directly driven into the foundation by a pile driver. The pile diameter of the pipe pile is usually 40 cm, the wall thickness is 6 cm, and there is a cavity in the middle with a size of 28 cm. A pile cap is set at the top of the pipe pile. The pile cap is generally made of cast-in-place concrete, usually in a square shape with a size of 1.2 m to 1.4 m and a thickness of 30 cm. Because there is a cavity and concrete needs to be poured, the function of sealing the chassis 6 is to prevent the poured concrete from falling into the cavity inside the pipe pile.

[0109] ⑧ Move the equipment to the next pile position and start the construction of the next pile body. After all the construction is completed, lay the geogrid, lay a cement soil cushion with a thickness of 30 to 50 cm, and roll it to the designed compaction degree to complete the construction of the composite foundation of the prestressed concrete pipe pile and the cement soil cushion.

[0110] In one embodiment, level the site, measure and set out the lines, and mark the pile positions of the pipe piles, including leveling the site according to the elevation characteristics of the site and establishing an adaptive dynamic pile position compensation algorithm based on the soil deformation parameters to achieve the measurement, setting out and marking of the pile positions of the pipe piles. Specifically, it includes:

[0111] S11. Select the corresponding leveling mode to level the site according to the relationship between the surface elevation and the designed elevation of the pile top;

[0112] S12. Based on the three-dimensional laser point cloud technology and the soil deformation parameters, establish an adaptive dynamic pile position compensation algorithm, and achieve the measurement and setting out of the lines through iterative optimization;

[0113] S13. Mark the pile positions of the pipe piles according to the results of the measurement and setting out of the lines;

[0114] Among them, the elevation characteristics of the site include the surface elevation and the designed elevation of the pile top; the soil deformation parameters include the slope angle parameter, the dynamic correction coefficient and the coordinate compensation amount; the coordinate compensation amount includes the horizontal direction compensation amount and the vertical direction compensation amount.

[0115] In one embodiment, S11 includes:

[0116] When the surface elevation is greater than the pile top elevation, excavate the excess height and level the site elevation to the designed elevation of the pile top;

[0117] When the surface elevation is equal to the pile top elevation, level it directly;

[0118] When the surface elevation is less than the pile top elevation, backfill and compact it to the designed elevation and compact and level it.

[0119] Specifically, the site leveling in this construction method ① includes three leveling modes: The first leveling mode is that the ground surface elevation is higher than the pile top elevation, and the excessive height part needs to be excavated to level the site elevation to the designed pile top elevation; the second leveling mode is that the ground surface elevation is equal to the pile top elevation, and then the site leveling can be completed; the third leveling mode is that the ground surface elevation is lower than the pile top elevation, and then it needs to be backfilled to the designed pile top elevation and compacted and leveled.

[0120] In one embodiment, S12 includes:

[0121] S121. Generate a digital elevation model of the site using three-dimensional laser point cloud and obtain the slope angle parameter;

[0122] S122. Based on the slope angle parameter, considering the influence of soil body deformation on the compensation amount, establish a dynamic correction coefficient;

[0123] S123. Calculate the compensation amounts in the horizontal and vertical directions according to the dynamic correction coefficient to obtain the coordinate compensation amount;

[0124] S124. Verify the pile position error through the measured pile position compensation amount and the predicted pile position compensation amount, and iteratively optimize the dynamic correction coefficient until the pile position error reaches the preset threshold, and then carry out measurement and setting out.

[0125] Specifically, in this construction method ①, the measurement and setting out process is realized by establishing an adaptive dynamic pile position compensation algorithm considering two soil body deformation parameters, namely the soil compression modulus and Poisson's ratio. The specific process includes:

[0126] a) Extract terrain features: Generate a digital elevation model of the site through three-dimensional laser point cloud and extract the slope angle. The expression is:

[0127]

[0128] b) Calculate the dynamic correction coefficient. Establish a dynamic correction considering the influence of soil body deformation on the compensation amount. The expression of the dynamic correction coefficient is:

[0129]

[0130] c) Calculate the coordinate compensation amount, including the horizontal direction compensation amount and the vertical direction compensation amount considering the three-dimensional curvature effect. Among them:

[0131] The expression of the horizontal direction compensation amount is:

[0132]

[0133] The expression of the vertical direction compensation amount is:

[0134]

[0135] d) Real-time calibration and iterative calculation. The measured pile position compensation amount is obtained through GNSS (Global Navigation Satellite System), and the pile position error is verified by comparing it with the predicted pile position compensation amount. The expression for the pile position error is:

[0136]

[0137] In the present invention, when ε > 10 mm, iterative optimization calculation is performed on the correction coefficient, and the expression is:

[0138]

[0139] Through multiple iterative calculations, the error is continuously reduced until the design requirements are met;

[0140] In the formula, θ x , θ y , θ z are the slope angles in the X, Y, and Z directions respectively; and are the slope change rates in the X and Y directions respectively; k x and k y are the dynamic correction coefficients in the X and Y directions respectively; ΔX, ΔY, and ΔZ are the pile position compensation amounts in the X, Y, and Z directions respectively; E is the measured value of the soil compression modulus; v is the soil Poisson's ratio; L p is the slope length; α is the slope direction azimuth angle; ε is the pile position positioning error; ΔX 实测 and ΔY 实测 are the measured pile position compensation amounts in the X and Y directions respectively; ΔX 计算 and ΔY 计算 are the predicted pile position compensation amounts in the X and Y directions respectively; k x new and k y new are the dynamic correction coefficients in the X and Y directions after iterative calculation respectively; k x old is the dynamic correction coefficient in the X direction before iterative calculation.

[0141] In one embodiment, based on the marked pile positions, the first or second pile driving mode is selected according to the foundation bearing capacity to complete the pipe pile construction, and the pile cap positions are marked.

[0142] In one embodiment, 1) The first pile driving mode is applicable to foundations with natural foundation bearing capacity less than the preset value, including:

[0143] When using static pile pressing, the pile sinking speed is controlled in two stages;

[0144] When using the hammering method, the corresponding hammer weight and hammer distance are selected according to the pile diameter, and the total number of hammer blows and the number of hammer blows per unit depth at the end are controlled based on the pile body concrete strength;

[0145] 2) The second pile driving mode is applicable to the foundation with natural foundation bearing capacity greater than or equal to the preset value, including:

[0146] When static pile pressing is adopted, the pile sinking speed is controlled in three stages;

[0147] When the hammering method is adopted, the corresponding hammer weight and hammer distance are selected according to the pile diameter, and the total number of hammer blows and the number of hammer blows per unit depth at the end are controlled based on the concrete strength of the pile body;

[0148] When pile sinking is difficult, a spiral drill rod is used for drilling or the water jet vibroflotation method is used for assisting pile sinking.

[0149] Specifically, in this construction method ②, the pile driving process is divided into two modes. The first pile driving mode is applicable to the foundation with natural foundation bearing capacity less than 100 kPa, and the second pile driving mode is applicable to the foundation with natural foundation bearing capacity greater than or equal to 100 kPa, such as the foundation with gravel layer or moderately weathered rock layer.

[0150] a) The first pile driving mode uses static pile pressing or hammering to drive piles. When static pile pressing is adopted, the present invention sets two-stage pile sinking speed:

[0151] Depth of 0 - 10 m: 1000 - 2000 mm / min;

[0152] Depth > 10 m: 600 - 1500 mm / min;

[0153] When hammering is used to drive piles, according to the different pile diameters, different hammer weights and hammer distances are adopted by the present invention (as shown in Table 1). When the concrete strength of the pile body is 60 - 80 MPa, the total number of hammer blows for pile sinking should not exceed 1000 blows, and the number of hammer blows in the last 1 meter should not exceed 100 blows. When the concrete strength of the pile body is greater than 80 MPa, the total number of hammer blows for pile sinking should not exceed 1500 blows, and the number of hammer blows in the last 1 meter should not exceed 150 blows.

[0154] Table 1 Hammering parameter table for the first pile driving mode

[0155] Pile diameter 400 500 600 Total hammer weight 6.2～7.2 7.2～9.2 9.5～12.5 Hammer spacing 1.6～2.6 1.7～3.2 2.0～3.6

[0156] b) The second pile driving mode uses static pile pressing or hammering to drive piles. When static pile pressing is adopted, the present invention sets three-stage pile sinking speed:

[0157] Depth of 0 - 5 m: 900 - 1700 mm / min;

[0158] Depth of 5 - 10 m: 700 - 1200 mm / min;

[0159] Depth > 10 m: 500 - 1000 mm / min;

[0160] When driving piles by means of hammering, in accordance with different pile diameters, the present invention respectively adopts different hammer weights and hammer distances (as shown in Table 2). When the concrete strength of the pile body is less than 80 MPa, the hammer distance should be selected as a low value, the total number of hammer blows for pile sinking should not exceed 2000 blows, and the number of hammer blows in the last 1 m should not exceed 200 blows. When the concrete strength of the pile body is greater than 80 MPa, the total number of hammer blows for pile sinking should not exceed 2500 blows, and the number of hammer blows in the last 1 m should not exceed 300 blows.

[0161] Table 2 Hammering Parameter Table for the Second Pile Driving Mode

[0162] Pile diameter 400 500 600 Total hammer weight 7.5～10.2 10.5～13.2 13.5～16.2 Hammer spacing 1.5～2.2 2.0～2.5 2.2～3.0

[0163] c) When pile sinking is difficult, a spiral drill rod with a diameter of 200 - 300 mm is used for drilling (rotation speed 20 - 40 r / min, torque 35 - 60 kN·m), or the water jet vibroflotation method (water pressure 10 - 15 MPa, flow rate 60 - 90 L / min) is adopted to assist pile sinking. When using the spiral drill rod for drilling to assist pile sinking, the drilling depth should be 1 / 2 - 3 / 4 of the pile length, and the diameter of the drill rod should match the diameter of the pipe pile. For a larger pipe pile diameter, a larger drill rod diameter is taken. When using the water jet vibroflotation method to assist pile sinking, a water pump is required to pump out the dispersed slurry. After pile sinking is completed, the cavity inside the pipe pile should be backfilled with subgrade fill not less than 1 / 2 of the pile length of the pipe pile.

[0164] To facilitate the understanding of the above technical solution of the present invention, the following takes the construction of a composite foundation of prestressed concrete pipe piles and cement soil cushions in an industrial park as an example for specific description as follows:

[0165] The construction site is a sandy clay foundation, and the bearing capacity of the natural foundation is less than 100 kPa. Prestressed concrete pipe piles (pile diameter 40 cm, pipe wall thickness 6 cm, middle cavity size 28 cm) are used for foundation treatment. First, the site is leveled according to the characteristics of the site elevation. Since the surface elevation is higher than the designed elevation of the pile top, the first leveling mode is adopted for excavation and leveling. Subsequently, the three-dimensional laser point cloud technology is used to obtain the digital elevation model of the site, and the measurement and setting out of the pile positions and the marking of the pile positions are completed through the adaptive dynamic pile position compensation algorithm, and iterative optimization is carried out until the pile position error is less than 10 mm.

[0166] Since the bearing capacity of the natural foundation is less than the preset value of 100 kPa, the first pile driving mode is selected for construction. The static pile pressing method is adopted. In the depth section of 0 - 10 m, the pile sinking speed is controlled at 1000 - 2000 mm / min, and in the depth section greater than 10 m, it is reduced to 600 - 1500 mm / min. After pile driving is completed, the construction equipment of the present invention is used for pile cap construction: The hydraulic traction device 5 is started to adjust the blade 3 to the vertical state, and the soil-taking louver basket 2 with a height of 30 cm and a width of 130 cm is pressed into the foundation through the hydraulic jack 8 (providing a pressure of 70 - 100 kN), so that the pile head ring 4 with an inner diameter of 62 cm is sleeved on the pile head of the pipe pile. Subsequently, the hydraulic power device 51 drives the blade 3 to rotate through the traction rope 52, and a hierarchical speed control is adopted: In the initial stage (0 - 30°), a low speed rotation of 1 - 2° / s is adopted, in the lifting stage (30 - 90°), a high speed rotation of 3 - 6° / s is adopted, and when the traction force exceeds 30 kN, a direction conversion is carried out.

[0167] After soil taking is completed, the soil-taking pit is compacted through the static pressure platform 1, a pile cap steel reinforcement cage with a square shape of 1.4 m and a thickness of 30 cm is placed, the plugging bottom plate 6 with a diameter of 58 cm is placed in the cavity of the pipe pile and fixed with a hook 7 with a length of 35 cm, and concrete is poured to the design thickness. After all pile foundation construction is completed, a geogrid is laid, a 50 cm thick cement soil cushion is covered, and it is rolled to the design required compaction degree to complete the construction of the composite foundation.

[0168] In summary, by means of the above technical solutions of the present invention, through the cooperation of the soil-taking louver basket 2 and the hydraulic traction device 5, the soil at the pile cap position can be taken out at one time, and the formed soil pit is used as a natural template for pouring concrete, which is convenient and fast, greatly improves the construction efficiency, reduces the project cost, and eliminates the cumbersome procedures of template installation and disassembly in traditional construction; at the same time, through the compaction effect of the static pressure platform 1, the stability of the soil pit wall surface is ensured, providing reliable forming conditions for pile cap pouring and significantly improving the construction efficiency. The construction equipment and method provided by the present invention can use the formed soil pit to replace the template for pouring the concrete pile cap of the pipe pile, greatly improving the construction efficiency of the prestressed concrete pipe pile; in addition, the present invention uses a cement soil cushion to replace the traditional gravel cushion and combines the laying of geogrid to form a composite structure with high stiffness, greatly reducing the construction cost and reducing the project cost by more than 20%. Moreover, the cement soil cushion has a large stiffness, which is more conducive to giving full play to the bearing capacity of the pile body of the prestressed concrete pipe pile. The present invention realizes the precise positioning of the pile position by establishing an adaptive dynamic pile position compensation algorithm based on the three-dimensional laser point cloud technology and the soil deformation parameters; the adaptive dynamic pile position compensation algorithm effectively controls the pile position error through the iterative optimization of the measured pile position compensation amount and the predicted pile position compensation amount, ensuring the positioning accuracy of the pipe pile construction and providing a reliable guarantee for the subsequent construction quality. The present invention sets two pile driving modes according to the bearing capacity of the foundation, adopts a sectional control of the pile sinking speed for different depths, and at the same time provides auxiliary pile sinking measures such as a spiral drill rod drilling and a water jet vibroflotation method. This classified construction plan effectively solves the pile sinking problems under different foundation conditions and improves the construction adaptability and efficiency.

[0169] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A prestressed concrete pipe pile cement soil cushion composite foundation construction equipment, characterized in that: It includes a static pressure platform, and a plurality of hydraulic jacks for providing downward pressure power and upward pressure power for the static pressure platform are arranged on the top of the static pressure platform; The bottom end of the static pressure platform is provided with a soil-taking louver basket for holding the soil dug by the blades; The bottom of the soil-taking louver basket is provided with a plurality of blades arranged in a linear manner for digging out the soil of the cushion layer; A pile head ring for passing through a prestressed concrete thin-walled pipe pile is provided at the bottom center of the soil-taking louver basket; A hydraulic traction device for driving the blades to rotate is arranged at the top of the soil taking louver basket.

2. The prestressed concrete pipe pile cement soil cushion composite foundation construction equipment according to claim 1, characterized in that: The soil-taking louver basket is configured as a box-shaped structure, the height of the box-shaped structure is smaller than the width, the four side walls of the box-shaped structure are provided with closed steel plates, a plurality of cross braces are provided in the middle of the box-shaped structure, the cross braces are vertically crossed with the blades, and the two sides of the pile head ring are fixedly connected to the cross braces.

3. The prestressed concrete pipe pile cement soil cushion composite foundation construction equipment according to claim 1, characterized in that: The blade is configured as a lamellar conical structure, which is wide in the vertical direction and narrow at the bottom and can rotate within a range of 180°; the top of the blade is hingedly connected to the bottom of the soil-taking louver basket, and a threading hole is provided at the bottom of the blade.

4. The prestressed concrete pipe pile cement soil cushion composite foundation construction equipment according to claim 1, characterized in that: The pile head ring is configured as a circular ring structure, and the inner diameter of the pile head ring is larger than the outer diameter of the prestressed concrete thin-walled pipe pile; A blocking chassis is arranged at the bottom of the pile head ring, and a plurality of hooks arranged in a circumference are fixedly arranged on the top of the blocking chassis. The hooks are connected to the pile head ring in a detachable hanging manner.

5. The prestressed concrete pipe pile cement soil cushion composite foundation construction equipment according to claim 3, characterized in that: The hydraulic traction device comprises a plurality of groups of hydraulic power devices, traction ropes and hinged joints symmetrically arranged on the top of the soil taking louver basket; Among them, each group of the hydraulic power device includes two hydraulic cylinders arranged opposite to each other, the two ends of the traction rope are respectively connected to the output ends of the two hydraulic cylinders, the middle part of the bottom end of the traction rope passes through the threading hole of the blade, and the hinged joint is arranged at the connection between the blade and the soil-taking louver basket; the two hydraulic cylinders repeatedly change the traction direction according to the size of the traction force to drive the blade to rotate to a completely horizontal state.

6. A method for constructing a composite foundation of prestressed concrete pipe piles with cement soil cushion, using the prestressed concrete pipe piles with cement soil cushion composite foundation construction equipment described in any one of claims 1 to 5, characterized in that: include: S1. Level the site, measure and lay out the lines, and mark the positions of the pipe piles; S2. Based on the marked pile position, select the first piling mode or the second piling mode according to the bearing capacity of the foundation to complete the pipe pile construction, and mark the pile cap position; S3, make the pile cap, control the blade rotation through the hydraulic traction device, and cooperate with the earth-taking louver basket to complete the soil excavation and cleaning; S4. Compact the soil pit through the static pressure platform, place the pile cap steel cage, place the plugging chassis in the pile cavity, hang the hook on the steel cage, and pour concrete to the required thickness; S5. Move the equipment to the next pile position. After completing all pile construction, lay the geogrid and cement soil cushion layer, and roll them to the compaction degree required by the design to complete the construction of the composite foundation.

7. The method for constructing a composite foundation of prestressed concrete pipe piles and cement soil cushion according to claim 6, characterized in that: The leveling of the site, measuring and laying out, and marking of the pipe pile positions include leveling the site according to the site elevation characteristics, and establishing an adaptive dynamic pile position compensation algorithm based on soil deformation parameters to achieve measurement, laying out, and marking of the pipe pile positions, specifically including: S11. According to the relationship between the ground elevation and the designed elevation of the pile top, select the corresponding leveling mode to level the site; S12. Based on 3D laser point cloud technology and soil deformation parameters, an adaptive dynamic pile position compensation algorithm is established, and measurement and layout are achieved through iterative optimization; S13. Mark the positions of the pipe piles according to the measurement and setting-out results; Among them, the site elevation characteristics include the ground elevation and the pile top design elevation; the soil deformation parameters include the slope angle parameter, the dynamic correction coefficient and the coordinate compensation; the coordinate compensation includes the horizontal compensation and the vertical compensation.

8. The method for constructing a composite foundation of prestressed concrete pipe piles and cement soil cushion according to claim 7, characterized in that: The S11 includes: When the surface elevation is greater than the pile top elevation, the super-elevated portion shall be excavated and the site elevation shall be leveled to the designed elevation of the pile top; When the ground elevation is equal to the pile top elevation, level it directly; When the ground elevation is lower than the pile top elevation, backfill and compact to the designed elevation, and then compact and level; The S12 includes: Generate a digital elevation model of the site using 3D laser point cloud to obtain slope angle parameters; Based on the slope angle parameter, the dynamic correction coefficient is established by considering the influence of soil deformation on the compensation amount; The compensation amounts in the horizontal and vertical directions are calculated according to the dynamic correction coefficients to obtain the coordinate compensation amounts; The pile position error is verified by measuring the pile position compensation and predicting the pile position compensation, and the dynamic correction coefficient is iteratively optimized until the pile position error reaches the preset threshold, and then measurement and layout are carried out.

9. A prestressed concrete pipe pile cement soil cushion composite foundation construction method according to claim 8, characterized in that: The expression of the dynamic correction coefficient is: The coordinate compensation expression is: The expression of the pile position error is: In the formula, θ x ,θ y ,θ z are the slope angles in the X, Y, and Z directions respectively; k x With k y are the dynamic correction coefficients in the X and Y directions respectively; ΔX, ΔY, ΔZ are the pile position compensations in the X, Y, and Z directions respectively; E is the measured value of the soil compression modulus; v is the Poisson's ratio of the soil; L p is the slope length; α is the slope azimuth; ε is the pile position error; ΔX 实测 and ΔY 实测 are the measured pile position compensation in the X and Y directions respectively; ΔX 计算 and ΔY 计算 They are the predicted pile position compensation amounts in the X and Y directions respectively.

10. The method for constructing a composite foundation of prestressed concrete pipe piles and cement soil cushion according to claim 6, characterized in that: The first piling mode is applicable to the foundation whose natural foundation bearing capacity is less than the preset value, and includes: When static pile driving is used, the pile driving speed is divided into two stages for control; When hammering is used, the corresponding hammer weight and hammer distance are selected according to the pile diameter, and the total number of hammer blows and the final number of hammer blows per unit depth are controlled based on the concrete strength of the pile body; The second piling mode is applicable to foundations with natural foundation bearing capacity greater than or equal to a preset value, including: When static pile driving is used, the pile driving speed is divided into three stages for control; When hammering is used, the corresponding hammer weight and hammer distance are selected according to the pile diameter, and the total number of hammer blows and the final number of hammer blows per unit depth are controlled based on the concrete strength of the pile body; When pile sinking is difficult, spiral drill rod drilling or water jet vibration method is used to assist pile sinking.

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