Pile foundation guide caisson structure and construction method thereof

Abstract

This invention discloses a pile-foundation guided caisson structure and its construction method, comprising caisson components and pile foundations. Multiple caisson components are stacked and settled sequentially. Several pile holes are uniformly and vertically drilled through the four sides of the caisson components. The stacked caisson components are connected by the pile foundations penetrating through the pile holes. The roots of the pile foundations are inserted into a stable clay layer or bedrock. Pile clamping components are installed or pre-embedded on the caisson components. The guide surface at the end of the pile clamping components extends into the pile hole and fits against the periphery of the pile foundation. The gap between the pile hole and the pile foundation is filled with concrete. This pile-foundation guided caisson structure, through the effective combination of pile foundations and caisson structures, is suitable for various poor foundations and can provide a more reliable support foundation for above-ground buildings. The pile foundations serve as guides for the lateral settlement of the caisson components, effectively controlling the sinking posture of the caisson components, improving construction efficiency, and reducing construction risks. This construction method flexibly utilizes the caisson components and pile foundations as mutual references, effectively improving construction quality and efficiency.

Description

Technical Field

[0001] This invention relates to the field of caisson construction technology, specifically to a pile foundation guided caisson structure and its construction method. Background Technology

[0002] A caisson is a cylindrical structure that is lowered to its designed elevation by excavating soil inside and allowing its own weight to overcome the frictional resistance of the caisson walls. The bottom is then sealed with concrete, and the caisson becomes the foundation for bridge piers or other structures. Due to their high rigidity, caissons are commonly used as foundations for buildings and retaining structures for underground structures. They are typically used in the construction of large bridge piers, foundations for large industrial equipment, subway stations, mine shafts, and sewage pumping stations.

[0003] Because caissons require soil to be removed from within them to allow for self-weight settlement, the settlement is uneven due to factors such as soil quality and uneven excavation. The caisson's posture is difficult to control during settlement, making it prone to tilting. Once tilted, adjustment is difficult, resulting in low construction efficiency, high safety risks, and even damage to the caisson layout. In addition, poor geological conditions during caisson construction, such as foundations with karst development or unstable overburden, can lead to self-settlement under load due to insufficient bearing capacity, thereby increasing the risk of collapse of above-ground buildings. Summary of the Invention

[0004] The purpose of this invention is to overcome the deficiencies of the prior art and provide a pile foundation guide caisson structure and its construction method to solve one or more problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A pile foundation guide caisson structure includes caisson components and pile foundation, wherein multiple caisson components are stacked and settled sequentially, and the lower edge of the caisson wall of the bottom caisson component is a sloped caisson wall cutting edge.

[0007] Several pile holes are evenly and vertically drilled through the four sides of the caisson component. The stacked caisson components are connected by piles penetrating through the pile holes. The roots of the piles are inserted into the stable clay layer or stable bedrock. Pile clamping components are installed or pre-embedded on the caisson components. The guide surface at the end of the pile clamping component extends out of the pile hole and fits against the periphery of the pile foundation. It is used to guide and limit the support of the caisson components. The gap between the pile hole and the pile foundation is filled with concrete.

[0008] Furthermore, drag-reducing sliding plates are installed between the four outer walls of the caisson component and the foundation wall as auxiliary accessories during the settlement construction process. The outer plate of the drag-reducing sliding plate is attached to the foundation wall, and several ball bearings are embedded in its inner plate. The outer wall of the caisson component slides against the inner plate to reduce the settlement resistance of the caisson component. The drag-reducing sliding plate is equipped with several hydraulic rods, which are connected to the lower end of the drag-reducing sliding plate and installed on the bottom caisson component. The hydraulic rods settle synchronously with the caisson component, and after settling a certain distance, they drive the drag-reducing sliding plate downward to eliminate the travel distance between them.

[0009] Furthermore, several hydraulic rods are encapsulated within a hydraulic rod box, which is detachably connected to the outer wall of the bottom caisson component. The drag-reducing slide plate is a spliced ​​structure of several sub-slide plates. The bottom sub-slide plates are located inside the hydraulic rod box and connected to the hydraulic rods. Throughout the sliding process, the lower edge of the bottom sub-slide plate is always located within the hydraulic rod box. The opening of the hydraulic rod box is equipped with a sealing strip to seal the gap between the sub-slide plates and the opening.

[0010] Furthermore, a triangular steel plate is installed at the bottom of the hydraulic rod box for the transition connection between the bottom of the box and the cutting edge of the well wall. A compression arc plate is horizontally installed on the outer side of the hydraulic rod box, and the top of the compression arc plate protrudes from the outer side of the hydraulic rod box for synchronously compressing and compacting the soil on the foundation wall when the caisson components descend.

[0011] Furthermore, several steel wire ropes are vertically installed on the drag-reducing slide plate, and the steel wire ropes are connected in series to the sub-slide plates in the same vertical group. The ends of the steel wire ropes are fixed to the hydraulic rod box, which is used to lift and remove the drag-reducing slide plate and the hydraulic rod box after the caisson structure has completed the settlement construction.

[0012] Furthermore, the pile clamping assembly includes an installation ring and a centering assembly. Several centering assemblies are fixed in a ring array on the installation ring and are all arranged radially along the installation ring. The centering assembly includes a support cylinder, an adjusting rod, and a ball. The installation ring is coaxially arranged with the pile hole. The support cylinder is threaded internally and has an adjusting rod that can extend and retract. The end of the adjusting rod extends out of the support cylinder and is embedded with a ball. The ball contacts the outer circumferential surface of the pile foundation.

[0013] A construction method for a pile foundation guide caisson structure includes the following steps:

[0014] S1. Compact and level the construction site, assemble the hydraulic rod and drag-reducing slide plate onto the outer wall of the bottom caisson component, and adjust the pile clamping assembly according to the pile foundation installation and pre-adjustment. If the pile clamping assembly has been pre-embedded, pre-adjust it, move the bottom caisson component to the preset construction position, excavate the soil inside the well, and control the verticality of the bottom caisson component until it is level with the ground.

[0015] S2. Lift all piles to the top of the bottom caisson structure and insert them into the pile holes. Fine-tune the pile clamping components on the bottom caisson structure as a verticality control guide for pile driving. Use the bottom caisson structure as a positioning guide for pile driving. When the pile reaches the design elevation, the root of the pile should be lower than the depth of the caisson and extend into the stable clay layer or stable bedrock. During the pile driving process, the verticality of the pile and the pile position deviation should be checked and adjusted at fixed points.

[0016] S3. Install the pile clamping assembly on the upper layer of the caisson component and hoist it to the construction position. Splice and connect the corresponding sub-slide plate of the caisson component of this layer. Adjust the pile clamping assembly according to the pile foundation and continue the excavation inside the caisson. Under the horizontal limit of the pile foundation and the pile clamping assembly, the caisson component maintains its posture and settles under its own weight as the excavation progresses. Each time the settlement height reaches the stroke distance of the hydraulic rod, the hydraulic rod is activated to drive the drag-reducing slide plate to descend step by step. Construct all layers of caisson components in this way and reach the design elevation of the caisson structure.

[0017] S4. Lift and remove the drag-reducing sliding plate and hydraulic rod, and backfill the ground around the caisson structure;

[0018] S5. Use a high-pressure water gun to clean the pile hole, pressurize and drain the mud and water in the pile hole, seal the gap between the bottom of the pile hole and the pile foundation, and after creating dry construction conditions, pour micro-expansion concrete into the pile hole from bottom to top to solidify the caisson structure and the pile foundation into an integrated structure.

[0019] S6. For the bottom of the caisson structure, first lay a layer of crushed stone on the foundation at the bottom of the caisson, then lay an impermeable cushion layer that can be isolated, pour sealing concrete underwater, and after it reaches the strength, pump out the water to form dry construction conditions, and finally pour the bottom slab.

[0020] Furthermore, the pile foundation is a hollow tube, with a fixed frame installed inside the tube. The settlement rope is wound around the fixed frame, with both ends extending out of the pile foundation tube opening. One end is connected to the end plate, and the other end is used to apply auxiliary force on the ground. The end plate is erected on the upper end of the pad tube, and the pad tube is coaxially erected on the upper end face of the pile hole.

[0021] Compared with the prior art, the pile foundation guide caisson structure and its construction method of the present invention have the following beneficial effects:

[0022] This pile-foundation guided caisson structure effectively combines pile foundations and caisson structures. The caisson foundation and pile foundation together serve as a supporting foundation, complementing each other's advantages and disadvantages. This foundation structure is suitable for various poor foundations and can provide a more reliable supporting foundation for above-ground buildings. At the same time, the pile foundation can also serve as a guide for the lateral settlement of the caisson components. By using pile clamping components for limiting support and guidance, the sinking posture of the caisson components can be effectively controlled, improving construction efficiency and reducing construction risks.

[0023] In addition, the proposed construction method flexibly utilizes the caisson components and pile foundations as references for settlement and pile embedding construction. Since the settlement construction quality of the bottom caisson components is easy to guarantee, the pile embedding construction uses the bottom caisson components as positioning guides to improve positioning accuracy and construction efficiency. The remaining caisson components are then limited and guided by the pile foundations, effectively improving construction quality and efficiency. By using a drag-reducing sliding plate to assist the settlement of the caisson structure, the settlement resistance is reduced, further avoiding uneven settlement and caisson tilting caused by friction differences in caisson components, and effectively solving the problems of difficult and sudden settlement accidents of caisson components. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the caisson structure disclosed in this invention under construction conditions;

[0025] Figure 2 This is a top view of the caisson structure disclosed in this invention during construction.

[0026] Figure 3 for Figure 2 A schematic diagram of the structure of the guide component;

[0027] Figure 4 This is a partial cross-sectional view of the caisson structure disclosed in this invention during construction.

[0028] Figure 5 for Figure 1 Schematic diagram of the mid-drag reduction sliding plate and hydraulic rod box;

[0029] Figure 6 This is a schematic diagram of the auxiliary settlement system.

[0030] In the diagram: 1. Caisson components; 11. Pile hole; 12. Structural protrusion; 2. Cushion layer; 3. Bottom sealing plate; 4. Crushed stone layer; 5. Pile foundation; 6. Hydraulic rod box; 61. Hydraulic rod; 62. Installation area; 63. Pull-slip area; 7. Resistance reducing slide plate; 8. Pile clamping assembly; 81. Installation ring; 82. Support cylinder; 83. Adjusting rod; 84. Rolling ball; 9. Extrusion arc plate; 10. Steel wire rope; 13. Fixing frame; 14. Pad pipe; 15. End plate; 16. Settlement pull rope. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely the best 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.

[0032] Pile foundations and caisson foundations are common underground foundations for above-ground buildings. Pile foundations have high bearing capacity and excellent performance in bearing vertical, horizontal, and vibration loads, and are also relatively inexpensive and have good settlement control. However, they have low stiffness. Caisson foundations, on the other hand, have high rigidity and high support strength. Therefore, the embodiments of this disclosure combine the advantages of both pile foundations and caissons in the design, proposing a pile-guided caisson structure, the structure of which is as follows: Figures 1-5 As shown, multiple caisson components 1 are stacked and settled in sequence. Several pile holes 11 are evenly distributed in the four sides of the caisson component 1. The pile holes 11 penetrate vertically through the caisson wall. The stacked caisson components 1 are connected by pile foundations 5 penetrating the pile holes 11. The root of the pile foundation 5 is lower than the elevation of the caisson structure. According to the geological distribution, the root of the pile foundation 5 should be inserted into the stable clay layer or stable bedrock.

[0033] To reduce settlement resistance, the pile hole 11 is larger than the pile foundation 5, and the pile hole 11 is connected to the pile foundation 5 for contact, limiting and guiding through the pile clamping assembly 8. The pile clamping assembly 8 can be pre-embedded in the caisson component 1, and the pre-embedded installation requires the provision of adjustment holes for the pile clamping assembly 8. Alternatively, an installation groove can be opened in the caisson component 1 to facilitate the installation and debugging of the pile clamping assembly 8. The pile clamping assembly 8 is supported and guided by several circumferentially uniformly arrayed centering components against the pile foundation 5. The guide surface on each centering component that abuts against the pile foundation 5 is a rollable cylindrical or spherical surface. The guide center established by the guide surfaces extending into the pile hole 11 is located on the central axis of the pile foundation 5. After the settlement construction is completed, the gap between the pile hole 11 and the pile foundation 5 is filled with concrete, and the two are solidified into an integrated structure, realizing the underground foundation jointly supported by the pile foundation 5 and the caisson foundation. Furthermore, the guiding effect of the pile foundation 5 is used to ensure the horizontal settlement posture of the caisson, which is conducive to the overall uniform settlement of the caisson structure.

[0034] To reduce the weight of the caisson component 1 and to create the installation structure for the pile clamping assembly 8, multiple structural protrusions 12 are provided on the inner wall of the caisson component 1. The corners of the wall are chamfered to form the installation structure. The caisson component 1 can have pile clamping grooves at both ends, or it can have grooves on the inner wall. When installing the pile clamping assembly 8, its orientation is adjusted so that as many centering components as possible have their root ends facing the structural protrusions 12. This makes it easier to set adjustment holes for the pile clamping assembly 8 on the structural protrusions 12.

[0035] In addition, the lower edge of the well wall of the bottom caisson component 1 is a sloped well wall cutting edge, and a connecting groove is opened on the inner wall of the bottom caisson component 1. The connecting groove is set near the upper part of the well wall cutting edge. The bottom of the caisson structure is laid from bottom to top in the following order: crushed stone layer 4, cushion layer 2, bottom sealing concrete and bottom sealing plate 3. The crushed stone layer 4 is laid flat on the foundation at the bottom of the well, and the cushion layer 2 is an impermeable isolation layer used to isolate the underground.

[0036] In one exemplary embodiment of this disclosure, during settlement construction, the uniformity of excavation cannot be guaranteed, and the uneven distribution of frictional force on the outer walls of the caisson component 1 is one of the reasons for uneven settlement. In fact, when the overall or local frictional force is too high, the caisson component 1 is prone to difficulty in settling or sudden sinking accidents, resulting in high construction risks. Therefore, this embodiment provides drag-reducing sliding plates 7 between the four outer walls of the caisson component 1 and the foundation wall to reduce and balance the frictional force on the four walls, ensuring the safe and stable operation of the caisson construction. The drag-reducing sliding plates 7, as auxiliary accessories during the settlement construction process, need to be removed after the settlement construction is completed. Figure 1 and Figure 4 As shown, the outer plate of the drag-reducing sliding plate 7 is attached to the foundation wall, and a number of balls are embedded in its inner plate. The balls are rotatable spheres or cylinders, which convert sliding friction into ball friction. The outer wall of the caisson component 1 is attached to the balls on the inner plate. With the side support of the sliding plate and the uniform excavation of the soil under the cutting edge of the caisson wall, the caisson component 1 can achieve controllable settlement.

[0037] Since the drag-reducing slide plate 7 and the caisson component 1 settle asynchronously, the settlement depth of the caisson component 1 is divided into several settlement strokes. The drag-reducing slide plate 7 is driven downward by hydraulic rods 61. Multiple hydraulic rods 61 are evenly distributed on the drag-reducing slide plate 7. The settlement stroke is set according to the maximum driving stroke of the hydraulic rods 61 and the single excavation height. The hydraulic rods 61 are installed on the bottom caisson component 1 and settle synchronously with the caisson component 1. During the settlement process, the hydraulic rods 61 are in a free state, and the influence of hydraulic pressure on the settlement of the caisson component 1 can be ignored. After the caisson component 1 settles to the settlement stroke distance in a single settlement or multiple settlements, the hydraulic rods 61 are activated to drive the drag-reducing slide plate 7 to follow the downward settlement of the caisson component 1, eliminating the stroke distance between the two.

[0038] This embodiment provides a specific installation method for the hydraulic rod 61, such as... Figure 4 and Figure 5 As shown, several hydraulic rods 61 are arranged in parallel and encapsulated in a hydraulic rod box 6 to avoid the impact of mud on the life of the hydraulic rods 61. The hydraulic rod box 6 is detachably connected to the outer wall of the bottom caisson component 1. The upper area of ​​the hydraulic box is the sliding area 63, and the lower area is the installation area 62. The hydraulic rods 61 are installed in the installation area 62. The lower outer side of the drag-reducing slide plate 7 is flat. It extends into the hydraulic rod box 6 and always slides in the sliding area 63. The opening of the hydraulic rod box 6 is equipped with a sealing strip to seal the gap between the lower outer side of the drag-reducing slide plate 7 and the opening of the box.

[0039] Meanwhile, the drag-reducing sliding plate 7 is a splicing structure composed of several sub-sliding plates assembled in a grid pattern. The sub-sliding plates are assembled on the ground along the wall of the ground caisson component 1. The bottom sub-sliding plate is located inside the hydraulic rod box 6 and connected to the hydraulic rod 61. In addition, to facilitate the dismantling of the drag-reducing sliding plate 7, refer again to Figure 5 Several steel wire ropes 10 are vertically installed on the drag-reducing slide plate 7. The steel wire ropes 10 are connected in series to the sub-slide plates in the same vertical group. The lower end of the slide plate is fixed to the hydraulic rod box 6, and the upper end extends to the ground. After the settlement construction of the caisson structure is completed, the connection between the hydraulic rod box 6 and the bottom caisson component 1 is disassembled. The drag-reducing slide plate 7 and the hydraulic rod box 6 are lifted as a whole, and the sub-slide plates are disassembled one by one on the ground until the hydraulic rod box 6 is finally lifted out and removed.

[0040] In addition, considering the impact of hydraulic rod box 6 on the settlement of caisson component 1, refer again... Figure 4 A triangular steel plate is provided at the bottom of the hydraulic rod box 6 to transition between the bottom of the box and the cutting edge of the well wall. In addition, a compression arc plate 9 is horizontally provided on the outer side of the hydraulic rod box 6. The lower end of the compression arc plate 9 is connected to the transition triangular steel plate, and its arc apex protrudes from the outer side of the hydraulic rod box 6. In this way, when the caisson component 1 descends, under its own weight, the triangular steel plate and the compression arc plate 9 cooperate to expel and compact the soil on the foundation wall, reducing the wall friction force when the drag-reducing slide plate 7 descends and is lifted.

[0041] The pile-holding assembly, as an adjustable positioning component of caisson component 1, has the following specific structure: Figure 3 As shown, it includes an installation ring 81 and a centering assembly. The installation ring 81 is larger than the pile hole 11 and is coaxially arranged with the pile hole 11. There are at least three centering assemblies, all arranged radially along the installation ring 81. The centering assembly is a telescopic structure, which includes a support cylinder 82, an adjusting rod 83 and a ball bearing 84. The support cylinder 82 is threaded onto the adjusting rod 83. The adjusting rod 83 is telescopic and extends into the pile hole 11. The end of the adjusting rod 83 is embedded with a ball bearing 84. The ball bearing 84 contacts the outer circumferential surface of the pile foundation 5. By rotating the adjusting rod 83, the ball bearing 84 contacts the circumferential surface of the pile foundation 5. The guide center is located by the three-legged centering principle. The guide center is collinear with the center line of the pile foundation 5, thereby preventing the caisson component 1 from tilting when it settles.

[0042] Another aspect of the embodiments of this disclosure also provides a construction method adapted to the pile foundation guide caisson structure, which includes the following steps:

[0043] S1. Detect the foundation structure, determine the pile insertion depth, and compact and level the construction site.

[0044] Assemble the hydraulic rod box 6 and the corresponding sub-slide plate onto the outer wall of the bottom caisson component 1. Pre-adjust the pile clamping assembly according to the shaft diameter of the pile foundation 5 and install it. If the pile clamping assembly has been pre-embedded, then perform the pre-adjustment.

[0045] Pile 5 is a hollow tube, which utilizes an auxiliary settlement system installed within the pile foundation, such as... Figure 6As shown, the auxiliary settlement system includes a fixed frame 13, a settlement rope 16, an end plate 15, and a pad pipe 14. The fixed frame 13 is fixedly installed inside the pile foundation 5 pipe as a force fulcrum. The settlement rope 16 is wound around the fixed frame 13, with both ends extending out of the pile foundation 5 pipe opening. One end is connected to the end plate 15, and the end plate 15 supports the upper end of the pad pipe 14. The pad pipe 14 is coaxially erected on the pile hole 11, and its lower end presses against the upper end surface of the caisson component 1. The settlement rope 16 can be used to apply auxiliary force on the ground, generating a downward settlement force on the end plate 15, which is transmitted to the corresponding pile position of the caisson component 1 through the pad pipe 14, assisting the settlement of the caisson component 1, facilitating the adjustment of the attitude of the caisson component 1, and improving the settlement construction efficiency.

[0046] The bottom caisson component 1 is hoisted to the preset construction position, and the soil inside the caisson is excavated. During the excavation and settlement construction inside the caisson, the verticality and sinking posture of the bottom caisson component 1 must be controlled until the bottom caisson component 1 is level with the ground.

[0047] S2. Using the bottom caisson component 1 as a positioning guide frame, the pile foundation 5 is buried. The pile foundation 5 is hoisted to the top of the corresponding pile hole 11 of the bottom caisson component 1 in sequence. After the pile foundation 5 is inserted into the pile hole 11 to stabilize it, the pile clamping component on the bottom caisson component 1 is finely adjusted so that the rolling ball 84 is rigidly in contact with the circumference of the pile. This serves as a guide for controlling the posture and verticality of the caisson component 1 during the pile driving construction. The pile foundation 5 is continuously advanced until its burial depth reaches the design elevation. At this time, the root of the pile foundation 5 should be lower than the caisson depth and extend into the stable clay layer or stable bedrock.

[0048] During pile driving construction, the verticality of the pile foundation and the pile position deviation should be checked and adjusted at fixed points.

[0049] S3. Similarly, the pile clamping assembly is assembled onto the upper layer caisson component 1 and hoisted onto the lower layer caisson component 1. The sub-slide plate of the caisson component 1 is spliced ​​and connected to the lower layer sub-slide plate. The pile clamping assembly is adjusted, and the steel plate or steel pipe at the upper end of the settlement rope is moved to the upper end of the upper layer caisson component 1. The excavation construction inside the well continues. Under the horizontal limit of the pile foundation 5 and the pile clamping assembly, the caisson component 1 maintains its posture and settles with its own weight and applied tension as the excavation progresses. Each time the settlement height reaches the travel distance of the hydraulic rod 61, the hydraulic system is started, and all hydraulic rods 61 synchronously drive the drag-reducing slide plate 7 to descend step by step.

[0050] Following these steps, all layers of caisson components 1 are constructed step by step, until the design elevation of the caisson structure is reached;

[0051] S4. Disassemble the connection of the hydraulic rod box 6, lift and remove the drag-reducing slide plate 7 and the hydraulic rod box 6, release the settlement rope, and backfill the foundation around the caisson structure with materials such as gravel, stone chips, and sand.

[0052] S5. Use a high-pressure water gun to clean the pile hole 11, pressurize and remove the mud and water in the pile hole 11, seal the gap between the bottom of the pile hole 11 and the pile foundation 5, and after forming dry construction conditions, pour micro-expansion concrete into the pile hole 11 from bottom to top through the pouring pipe to solidify the caisson structure and the pile foundation 5 into an integrated structure.

[0053] S6. For the bottom of the caisson structure, first lay a layer of crushed stone 4 on the foundation at the bottom of the caisson, then lay an impermeable cushion layer 2 that can be isolated, and pour sealing concrete underwater. After it reaches the strength, pump out the water to form dry construction conditions, and finally pour the cast-in-place concrete sealing slab 3 with tied steel bars.

[0054] The directional terms "upper," "lower," "side," "end," "layer," "end," "root," "inner," and "outer" mentioned in this article are used to describe... Figures 1-5 The directions and orientations shown in the corresponding figures are described. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a particular orientation, or to be constructed and operated in a particular orientation;

[0055] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may, in certain circumstances, indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pile foundation guide caisson structure, characterized by: It includes caisson components and pile foundations, wherein multiple caisson components are stacked and settled in sequence, and the lower edge of the caisson wall of the bottom caisson component is a sloping cutting edge. The caisson component has several pile holes evenly and vertically drilled through its four sides. The stacked caisson components are connected in series through the pile holes of the pile foundation. The roots of the pile foundation are inserted into the stable clay layer or stable bedrock. A pile clamping assembly is installed or pre-embedded on the caisson component. The guide surface at the end of the pile clamping assembly is located in the pile hole and fits against the periphery of the pile foundation to guide and limit the support of the caisson component. The gap between the pile hole and the pile foundation is filled with concrete.

2. A pile guided caisson structure according to claim 1, characterised in that: Each of the four outer walls of the caisson component is equipped with a drag-reducing sliding plate between itself and the foundation wall. These plates serve as auxiliary components during the settlement process. The outer plate of the drag-reducing sliding plate is flush against the foundation wall, while its inner plate is embedded with several ball bearings. The outer wall of the caisson component slides against the inner plate of the drag-reducing sliding plate to reduce the settlement resistance of the caisson component. The drag-reducing sliding plate is equipped with several hydraulic rods. These hydraulic rods are connected to the lower end of the drag-reducing sliding plate and installed on the bottom layer of the caisson component. The hydraulic rods settle synchronously with the caisson component and, after settling a certain distance, drive the drag-reducing sliding plate downwards to eliminate the distance between them.

3. The pile foundation guide caisson structure according to claim 2, characterized in that: Several hydraulic rods are encapsulated within a hydraulic rod box, which is detachably connected to the outer wall of the bottom caisson component. The drag-reducing slide plate is a spliced ​​structure of several sub-slide plates. The bottom sub-slide plates are located within the hydraulic rod box and connected to the hydraulic rods. Throughout the sliding process, the lower edge of the bottom sub-slide plates remains within the hydraulic rod box. A sealing strip is provided at the opening of the hydraulic rod box to seal the gap between the sub-slide plates and the opening.

4. A pile guided caisson structure according to claim 3, characterised in that: A triangular steel plate is installed at the bottom of the hydraulic rod box for transition connection between the bottom of the box and the cutting edge of the well wall. A compression arc plate is horizontally installed on the outer side of the hydraulic rod box, and the arc top of the compression arc plate protrudes from the outer side of the hydraulic rod box for synchronously compressing and compacting the foundation wall soil when the caisson component descends.

5. The pile foundation guide caisson structure according to claim 3, characterized in that: Several steel wire ropes are vertically installed on the drag-reducing slide plate, and the steel wire ropes are connected in series to the sub-slide plates in the same vertical group. The ends of the steel wire ropes are fixed to the hydraulic rod box, and are used to lift and remove the drag-reducing slide plate and the hydraulic rod box after the caisson structure has completed the settlement construction.

6. A pile guided caisson structure according to claim 3, characterised in that: The pile clamping assembly includes an mounting ring and a centering assembly. Several centering assemblies are arranged in a ring array and fixed on the mounting ring, and are all arranged radially along the mounting ring. The centering assembly includes a support cylinder, an adjusting rod, and a ball. The mounting ring is coaxially arranged with the pile hole. The adjusting rod is threaded internally in the support cylinder and is telescopically mounted. The end of the adjusting rod extends out of the support cylinder and is embedded with the ball. The ball contacts the outer circumferential surface of the pile foundation.

7. A construction method for a pile foundation guide caisson structure as described in any one of claims 3 to 6, characterized in that, Includes the following steps: S1. Compact and level the construction site, assemble the hydraulic rod and the drag-reducing slide plate onto the outer wall of the bottom caisson component, install the pile foundation and pre-adjust the pile clamping assembly (if the pile clamping assembly has been pre-embedded), move the bottom caisson component to the preset construction position, excavate the soil inside the well, and control the verticality of the bottom caisson component until it is level with the ground. S2. Lift all the pile foundations above the bottom caisson component and insert them into the pile holes. Fine-tune the pile clamping assembly on the bottom caisson component as a verticality control guide for pile driving. Use the bottom caisson component as a positioning guide for pile driving until the design elevation is reached, with the root of the pile foundation extending into the stable clay layer or stable bedrock. During pile driving, the verticality and position deviation of the pile foundations should be checked and adjusted at fixed points. S3. Install the pile clamping assembly on the upper layer of the caisson component and hoist it to the construction position. Connect the corresponding sub-slide plate of the caisson component at this layer. Adjust the pile clamping assembly according to the pile foundation and continue the excavation inside the caisson. Under the horizontal limit of the pile foundation and the pile clamping assembly, the caisson component maintains its posture and settles under its own weight as the excavation progresses. Each time the settlement height reaches the stroke distance of the hydraulic rod, the hydraulic rod is activated to drive the drag-reducing slide plate to descend step by step. Construct all layers of the caisson components in this way and reach the design elevation of the caisson structure. S4. Lift and remove the drag-reducing slide plate and the hydraulic rod, and backfill the foundation around the caisson structure; S5. Use a high-pressure water gun to clean the pile hole, pressurize and drain the mud and water in the pile hole, seal the gap between the bottom of the pile hole and the pile foundation, and after forming dry construction conditions, pour micro-expansion concrete into the pile hole from bottom to top to solidify the caisson structure and the pile foundation into an integrated structure. S6. To construct the bottom of the caisson structure, first lay a layer of crushed stone on the foundation at the bottom of the caisson, then lay an impermeable pad layer that can be isolated, pour sealing concrete underwater, and after it reaches the required strength, pump out the water to create dry construction conditions, and finally pour the bottom slab.

8. The construction method according to claim 7, characterized in that: The pile foundation is a hollow tube with a fixed frame inside. Settlement ropes are wound around the fixed frame, with both ends extending out of the pipe opening. One end is connected to an end plate, and the other end is used to apply auxiliary force. The end plate is mounted on the upper end of the pad tube, and the pad tube is coaxially erected on the upper end face of the pile hole.

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