A composite pile foundation structure that resists horizontal forces
By increasing the width of the pile body and strengthening the soil in the passive pressure zone, a composite pile foundation structure designed with a combination of cement-soil external piles and precast core piles was adopted, which solved the problem of insufficient horizontal resistance of pile foundations in soft soil areas, and achieved efficient utilization and cost reduction of pile foundation structure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG PROVINCE METALLURGICAL ENG CO LTD
- Filing Date
- 2025-07-24
- Publication Date
- 2026-08-04
AI Technical Summary
In soft soil areas, existing composite pile foundation structures have insufficient bearing capacity against horizontal forces and high construction costs. In particular, the passive earth pressure zone of the pile foundation has not been effectively reinforced, resulting in an insignificant improvement in the pile foundation's resistance to horizontal bearing capacity.
A composite pile foundation structure is adopted. By increasing the calculated width of the pile body and strengthening the soil within the punching shear failure surface of the passive pressure zone, a composite pile foundation structure with a triangular arrangement is formed by using a combination design of cement-soil outer piles and precast core piles. This enhances the interaction between the pile and the soil and improves the horizontal bearing capacity.
It improves the horizontal bearing capacity of pile foundations, reduces foundation construction costs, and achieves efficient utilization and cost-saving effects of pile foundation structures.
Smart Images
Figure CN224591479U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of building engineering technology, and specifically relates to a composite pile foundation structure that resists horizontal forces. Background Technology
[0002] Based on the site's geological conditions and the stress characteristics of the material yard shed, pile foundations are commonly used for the foundations of material yard enclosure projects in soft soil areas. The horizontal bearing capacity of the piles is used to resist the horizontal thrust at the shed supports. In soft soil areas, the horizontal bearing capacity of a single cast-in-place pile or precast pipe pile is far less than its vertical bearing capacity. This significantly increases the number of piles required to control horizontal thrust, leading to higher foundation treatment costs. Conversely, the vertical bearing capacity of the piles is underutilized, with a certain degree of surplus.
[0003] To address the significant horizontal thrust characteristic of arch-shaped foundation structures, strengthening and fully utilizing the soil around the piles, and considering the combined action of the piles and soil in the pile foundation's horizontal thrust resistance design, the development of a composite pile foundation structure with high horizontal bearing capacity specifically designed to resist horizontal forces is of great significance for reducing foundation costs. According to the "Technical Code for Building Pile Foundations" JGJ94-2008, when a pile fails horizontally, the punching shear surface of the soil in the passive earth pressure zone behind it is distributed at 30°–45°. Therefore, increasing the pile diameter and improving the soil strength in the 30°–45° punching shear failure surface of the passive earth pressure zone behind the pile can effectively improve the horizontal bearing capacity of the pile.
[0004] To improve the horizontal resistance of the soil between piles in areas with poor surface soil quality by utilizing the combined action of piles and soil, the applicant's patent application ZL202021815285.1, "A Pile Foundation Structure," proposes to strengthen the stiffness of the soil between composite piles by installing interlocking cement-soil mixing piles in both the horizontal and vertical directions to meet the horizontal bearing capacity requirements of the composite pile foundation. While this technical solution can improve the horizontal bearing capacity of the pile foundation to some extent, it only improves the soil around the piles within the pile cap area. Furthermore, the cement-soil mixing piles are arranged orthogonally in both the horizontal and vertical directions, and the reinforcement location is not within the punching shear failure surface of the piles. Therefore, it fails to directly and effectively reinforce the soil in the passive earth pressure zone, resulting in an insignificant improvement in the horizontal bearing capacity of the pile foundation. Additionally, the interlocking construction is difficult and costly.
[0005] The applicant's patent application ZL202011130015.1, "A Multi-Pile Composite Pile Foundation Structure, Pile Foundation and its Construction Method," is aimed at soil layers with foundation liquefaction. It adds sand and gravel piles to treat foundation liquefaction based on ZL202021815285.1, "A Pile Foundation Structure." However, it still does not solve the defect that the soil reinforcement position of the previous patent is not within the range of the pile punching shear failure surface. It does not fundamentally and effectively reinforce the soil in the passive earth pressure zone, and the improvement effect on the horizontal bearing capacity of the pile foundation is not obvious.
[0006] Currently, there is considerable research on the vertical bearing capacity of composite pile foundations, but less research on their horizontal bearing capacity. For pile foundations primarily subjected to horizontal forces, researching and inventing a pile foundation structure that fully utilizes the combined horizontal interaction between the pile and soil is a pressing issue for structural and geotechnical engineers. This invention aims to develop a composite pile foundation structure that resists horizontal forces. By strengthening the pile and the soil within the punching shear failure surface of its passive pressure zone, it enhances the combined pile-soil interaction, improves the horizontal bearing capacity of the pile foundation, thereby saving on construction costs and contributing to energy conservation and emission reduction goals. Utility Model Content
[0007] To address the aforementioned problems, this utility model aims to develop a composite pile foundation structure that resists horizontal forces. The composite pile foundation structure employs a composite pile with an increased calculated width, while simultaneously strengthening the soil within the punching shear failure surface of the passive pressure zone, increasing the horizontal resistance coefficient of the foundation soil around the pile, enhancing the interaction between the pile and the soil, and improving the horizontal bearing capacity of the pile foundation structure, thereby achieving the goal of saving foundation construction costs.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] A composite pile foundation structure for resisting horizontal forces is provided, comprising composite piles, cement-soil mixing piles, and a pile cap structure. The composite piles consist of precast core piles and cement-soil outer piles surrounding them. The precast core piles are connected to the pile cap structure, and the composite piles are arranged in a triangular pattern under the pile cap structure. The cement-soil mixing piles are arranged in a triangular pattern behind the composite piles along the direction of horizontal thrust to form a composite pile foundation structure for resisting horizontal forces.
[0010] The composite foundation pile is first formed into a cement-soil outer pile through a mixing or jet grouting process. The diameter of the cement-soil outer pile is 1.5 to 2 times the diameter of the precast core pile, and the depth of the cement-soil outer pile is not less than 5 times the diameter of the cement-soil outer pile. Then, the precast core pile is driven into the cement-soil outer pile in the center, and the bottom of the precast core pile enters the bearing layer.
[0011] The precast core piles are high-strength prestressed hollow pipe piles, and the core piles are filled with concrete. The depth of the concrete core is the same as the depth of the cement-soil outer pile.
[0012] The pier structure is a three-pile pier, with the center-to-center spacing of the composite piles not less than twice the diameter of the cement-soil outer pile, and the top of the precast core pile embedded in the pier structure to a depth of not less than 100mm, with the reinforcing steel of the precast core pile anchored into the pier structure.
[0013] Cement-soil mixing piles are formed using mixing or jet grouting processes. Each composite foundation pile is equipped with two cement-soil mixing piles, and the diameter and depth of the cement-soil mixing piles are the same as those of the outer cement-soil piles of the composite foundation pile.
[0014] The composite pile foundation structure for resisting horizontal forces proposed in this utility model has the following advantages:
[0015] 1. Compared with traditional pile foundation structures, the composite pile foundation with cement-soil external piles increases the calculated width of the pile body. At the same time, by strengthening the soil within the punching shear failure surface of the passive pressure zone, the horizontal resistance coefficient of the foundation soil around the pile is improved, the pile-soil interaction is enhanced, and the horizontal bearing capacity of the pile foundation structure is improved.
[0016] 2. It allows the horizontal and vertical bearing capacity of the foundation piles to be fully utilized and utilized simultaneously, avoiding the problem of excessive vertical bearing capacity.
[0017] 3. Compared with traditional pile foundation structures, it can reduce the number of piles and the size of the pile cap, and the overall cost can be reduced by 10% to 15%.
[0018] 4. High-strength prestressed hollow pipe piles are a technologically mature product that is mass-produced in the market. Using high-strength prestressed hollow pipe piles as precast core piles for composite foundation piles facilitates the standardized design and industrialized production of foundation piles, which is of great significance for promoting the industrialization of building foundations. Attached Figure Description
[0019] Figure 1 A top view of a composite pile foundation structure resisting horizontal forces according to this utility model.
[0020] Figure 2 Schematic diagram of the composite foundation pile of this utility model
[0021] Figure 3 A schematic diagram of the vertical structure of a composite pile foundation resisting horizontal forces according to this utility model.
[0022] In the diagram, 1-composite pile; 11-precast core pile; 12-cement-soil external pile; 13-concrete core filler; 2-cement-soil mixing pile; 3-pillar structure. Detailed Implementation
[0023] The following description, in conjunction with the accompanying drawings, details the specific implementation of a composite pile foundation structure for resisting horizontal forces proposed in this utility model.
[0024] As attached Figures 1-3 As shown, a composite pile foundation structure resisting horizontal forces is provided. The composite pile foundation structure consists of composite piles 1, cement-soil mixing piles 2, and a pile cap structure 3. The composite piles 1 consist of precast core piles 11 and cement-soil outer piles 12 surrounding them. The precast core piles 11 are connected to the pile cap structure 3, and the composite piles 1 are arranged in a triangular pattern under the pile cap structure 3. The cement-soil mixing piles 2 are arranged in a triangular pattern behind the composite piles 1 along the direction of horizontal thrust to form a composite pile foundation structure resisting horizontal forces.
[0025] As attached Figure 2 As shown, the composite pile 1 first forms a cement-soil outer pile 12 through a mixing or jet grouting process. The diameter of the cement-soil outer pile 12 is 1.5 to 2 times the diameter of the precast core pile 11, and the depth of the cement-soil outer pile 12 is not less than 5 times the diameter of the cement-soil outer pile 12. Then, the precast core pile 11 is driven into the cement-soil outer pile 12 in the center, and the bottom of the precast core pile 11 enters the bearing layer.
[0026] As attached Figure 2 , Figure 3 As shown, the precast core pile 11 is a high-strength prestressed hollow pipe pile, which is processed and manufactured in the factory. The precast core pile 11 is filled with concrete core 13, and the depth of the concrete core 13 is the same as the depth of the cement-soil outer pile 12.
[0027] As attached Figure 1 , Figure 3 As shown, the pier structure 3 is a three-pile pier, the center-to-center spacing of the composite pile 1 is not less than twice the diameter of the cement-soil outer pile 12, the top of the precast core pile 11 is embedded in the pier structure 3 to a depth of not less than 100mm, and the steel bars of the precast core pile 11 are anchored into the pier structure 3.
[0028] As attached Figure 1 , Figure 3 As shown, the cement-soil mixing pile 2 is formed by mixing or jet grouting. Each composite pile 1 is equipped with two cement-soil mixing piles 2. The diameter and depth of the cement-soil mixing pile 2 are the same as the cement-soil outer pile 12 of the composite pile 1.
[0029] The above embodiments are merely advantages, features, and basic principles of this utility model. It should be understood that this utility model is not limited to the above embodiments. Without departing from the concept of this utility model, there may be new changes and improvements, all of which fall within the protection scope of this utility model.
Claims
1. A composite pile foundation structure resisting horizontal forces, characterized in that: The composite pile foundation structure consists of composite piles, cement-soil mixing piles, and a pile cap structure. The composite piles consist of precast core piles and cement-soil outer piles surrounding them. The precast core piles are connected to the pile cap structure, and the composite piles are arranged in a triangular pattern under the pile cap structure. The cement-soil mixing piles are arranged in a triangular pattern behind the composite piles along the horizontal thrust direction to form a composite pile foundation structure that resists horizontal forces.
2. A composite pile foundation structure to resist horizontal forces according to claim 1, wherein: The composite foundation pile is first formed into a cement-soil outer pile through a mixing or jet grouting process. The diameter of the cement-soil outer pile is 1.5 to 2 times the diameter of the precast core pile, and the depth of the cement-soil outer pile is not less than 5 times the diameter of the cement-soil outer pile. Then, the precast core pile is driven into the cement-soil outer pile in the center, and the bottom of the precast core pile enters the bearing layer.
3. A composite pile foundation structure to resist horizontal forces according to claim 1, wherein: The precast core piles are high-strength prestressed hollow pipe piles, and the core piles are filled with concrete. The depth of the concrete core is the same as the depth of the cement-soil outer pile.
4. The composite pile foundation structure of claim 1, wherein: The pier structure is a three-pile pier, with the center-to-center spacing of the composite piles not less than twice the diameter of the cement-soil outer pile, and the top of the precast core pile embedded in the pier structure to a depth of not less than 100mm, with the reinforcing steel of the precast core pile anchored into the pier structure.
5. The composite pile foundation structure of claim 1, wherein: Cement-soil mixing piles are formed using mixing or jet grouting processes. Each composite foundation pile is equipped with two cement-soil mixing piles, and the diameter and depth of the cement-soil mixing piles are the same as those of the outer cement-soil piles of the composite foundation pile.