Pile-raft composite foundation structure
Patent Information
- Application Number
- CN202522368849.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-11-07
AI Technical Summary
现有的桩筏复合地基设计主要依赖碎石层的颗粒级配特性实现桩土荷载的初步分配，碎石颗粒虽然硬度高但其抗裂性差，但当荷载突变，碎石容易被压碎，易导致桩土荷载分担比例失衡，同时，在高水位地质中，地下水易渗透至碎石层内部，导致碎石颗粒软化，进而破坏桩土荷载分配的均衡性，因此，现有的地基结构的长期性能与安全性有待提高
1.通过若干组锚固杆将上部荷载纵向传递至软土层，通过弹性承压层将荷载分散至第一碎石层和第二碎石层，且弹性承压层位于第一碎石层和第二碎石层之间，初步带动桩间土均匀受力，有利于维护回填层的使用性能，同时，通过设置环形集水槽、回填层内的积水通过竖向排水管和横向排水管排水，横向排水管延伸至外壁集水渠等，将渗透至回填层内部的水分排出，防止碎石颗粒软化，同时通过防水层避免水分下渗至软土层，从而维持桩土荷载分配的均衡性，提高了结构的稳定性，有利于延长地基结构的长期性能与安全性。
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Figure CN224813149U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of foundation structure technology, and in particular to pile-raft composite foundation structures. Background Technology
[0002] As a highly efficient form of foundation treatment, pile-raft composite foundations achieve the transfer of upper loads to deep stable soil layers through the synergistic effect of rigid piles, inter-pile soil, crushed stone layers, and raft slabs. They are widely used in engineering fields with stringent requirements for foundation performance, such as high-rise buildings, high-speed railways, and heavy industrial plants. Existing pile-raft composite foundation designs mainly rely on the particle size distribution characteristics of the crushed stone layer to achieve the initial distribution of pile-soil loads. Although crushed stone particles have high hardness, they have poor crack resistance. However, when the load changes abruptly, the crushed stone is easily crushed, which can easily lead to an imbalance in the pile-soil load sharing ratio. At the same time, in high-water-level geological conditions, groundwater can easily seep into the interior of the crushed stone layer, causing the crushed stone particles to soften and thus disrupting the balance of pile-soil load distribution. Therefore, the long-term performance and safety of existing foundation structures need to be improved. Therefore, this application provides a pile-raft composite foundation structure. Utility Model Content
[0003] In view of the shortcomings of the prior art, this application provides a pile-raft composite foundation structure, which overcomes the shortcomings of the prior art and aims to solve the problems in the prior art.
[0004] To achieve the above objectives, this application provides the following technical solution: a pile-raft composite foundation structure, including a lower layer, a soft soil layer laid at the top of the lower layer, a backfill layer above the soft soil layer, the backfill layer including a first crushed stone layer laid at the top of the soft soil layer, an elastic bearing layer above the first crushed stone layer, a waterproof layer fixedly installed at the top of the soft soil layer, several sets of anchor rods fixedly installed inside the elastic bearing layer, the bottom ends of the anchor rods extending into the interior of the soft soil layer, a second crushed stone layer laid above the elastic bearing layer, a cast-in-place raft slab fixedly installed above the second crushed stone layer, a road surface layer fixedly installed above the cast-in-place raft slab, an annular water collection trough at the bottom of the second crushed stone layer, several sets of vertical drainage pipes fixedly installed at the bottom of the second crushed stone layer at the annular water collection trough, the bottom ends of the vertical drainage pipes extending into the bottom of the soft soil layer, and a horizontal drainage pipe fixedly installed at the bottom end of the vertical drainage pipes on the same side.
[0005] By adopting the above technical solution, the upper load is longitudinally transferred to the soft soil layer through several sets of anchor rods, and the load is distributed to the first and second crushed stone layers through the elastic bearing layer. The elastic bearing layer is located between the first and second crushed stone layers, which initially promotes uniform stress on the soil between the piles, which is conducive to maintaining the service performance of the backfill layer. At the same time, by setting up an annular water collection trough, and draining the water accumulated in the backfill layer through vertical and horizontal drainage pipes, with the horizontal drainage pipes extending to the water collection channel on the outer wall, the water that has seeped into the backfill layer is discharged, preventing the crushed stone particles from softening. Meanwhile, the waterproof layer prevents water from seeping into the soft soil layer, thereby maintaining the balance of pile-soil load distribution, improving the stability of the structure, and helping to extend the long-term performance and safety of the foundation structure.
[0006] As a preferred embodiment of this application, the elastic bearing layer includes a bearing plate, which is installed between the first and second crushed stone layers. A force transmission tube is fixedly installed on the outer surface of the anchor rod, and the force transmission tube is located inside the bearing plate. Several sets of radial reinforcing ribs are fixedly installed on the outer periphery of the force transmission tube. An outer ring is fixedly installed at one end of the radial reinforcing ribs away from the force transmission tube. A tapered reinforcing rib is fixedly installed on the outer surface of the anchor rod directly below the force transmission tube. Several sets of reinforcing seats are fixedly installed between the tapered reinforcing ribs and the outer ring.
[0007] By adopting the above technical solution, the vertical load transmitted by the anchor rod is converted into radial force and transmitted to the outer ring through the force transmission tube and several sets of radial reinforcing ribs. When the load changes abruptly, several sets of reinforcing seats can decompose part of the vertical impact force, thereby reducing the stress burden on the anchor rod.
[0008] As a preferred technical solution of this application, the bottom end of the cast raft slab is provided with an anchoring groove that matches a plurality of sets of anchoring rods, and the top end of the anchoring rod is engaged in the anchoring groove.
[0009] By adopting the above technical solution, the anchor rod is connected to the cast raft slab through the anchor groove in a mortise and tenon joint manner. When the anchor rod is subjected to horizontal load, the stability of the connection between the anchor rod and the cast raft slab is ensured. At the same time, the load is directly transferred to the cast raft slab through the anchor rod, which helps to reduce the stress burden on the backfill layer and the elastic bearing layer.
[0010] As a preferred technical solution of this application, several groups of radial reinforcing ribs are radially distributed along the outer peripheral surface of the force transmission tube, and several groups of reinforcing seats are arranged in an inverted conical shape.
[0011] By adopting the above technical solution, the concentrated load of the radial stiffener is uniformly transferred to the outer ring radially through several sets of force transmission tubes, which improves the uniformity of load distribution. The several sets of stiffening seats are arranged in an inverted conical structure that is wider at the top and narrower at the bottom, forming a three-dimensional load transfer network, which can better transfer the load on the anchor rod downward.
[0012] As a preferred technical solution of this application, crushed stone geotextile sleeves are provided on both the upper and lower sides of the bearing plate. The crushed stone geotextile sleeves include several sets of transverse reinforcing strips and longitudinal reinforcing strips. The several sets of transverse reinforcing strips and longitudinal reinforcing strips are fixedly installed with the bearing plate, and the several sets of transverse reinforcing strips and longitudinal reinforcing strips are connected in the warp and weft directions.
[0013] By adopting the above technical solution, the impact resistance of the pressure plate can be improved by using several sets of transverse and longitudinal reinforcing strips connected in a warp and weft direction, thereby improving the load-bearing capacity of the pressure plate.
[0014] As a preferred technical solution of this application, the anchor rod has a grouting hole inside, and a number of grouting branch pipes are fixedly installed at the bottom of the anchor rod, and the grouting branch pipes are connected to the anchor rod.
[0015] By adopting the above technical solution, during construction, grout can be injected into the soil around the anchor rod through the grouting hole. The grout diffuses into the surrounding soil through the grouting branch pipe, filling the soil pores, enhancing the friction and adhesion between the soil and the anchor rod, and improving the anchoring effect.
[0016] As a preferred technical solution of this application, the top of the pressure plate is provided with several sets of grooves, and the bottom of the first crushed stone layer is embedded in several sets of grooves.
[0017] By adopting the above technical solution, the bottom of the first crushed stone layer is embedded in several sets of grooves to form a tight connection with the bearing plate. The crushed stone geotextile further enhances the frictional embedding between the two. When subjected to the upper load, the first crushed stone layer can efficiently transfer the load to the bearing plate through the grooves. At the same time, it avoids the problem of poor load transfer caused by relative sliding or separation between the first crushed stone layer and the bearing plate, ensuring the stability of pile-soil load distribution and enhancing the overall performance of the foundation structure.
[0018] As a preferred technical solution of this application, a woven layer is fixedly installed on the outer surface of both the first crushed stone layer and the second crushed stone layer.
[0019] By adopting the above technical solution, the woven layer is made of high-strength polyester fiber. The woven layer can evenly distribute the load acting on the crushed stone layer to a certain extent, thereby enhancing the crushed stone layer's ability to resist the influence of external factors.
[0020] The beneficial effects of this application are: 1. The upper load is longitudinally transferred to the soft soil layer through several sets of anchor rods, and the load is distributed to the first and second crushed stone layers through the elastic bearing layer. The elastic bearing layer is located between the first and second crushed stone layers, which initially promotes uniform stress on the soil between the piles, which is conducive to maintaining the service performance of the backfill layer. At the same time, by setting up a ring-shaped water collection trough, and draining the water accumulated in the backfill layer through vertical and horizontal drainage pipes, and extending the horizontal drainage pipes to the water collection channel on the outer wall, the water that has seeped into the backfill layer is drained, preventing the crushed stone particles from softening. At the same time, the waterproof layer prevents water from seeping into the soft soil layer, thereby maintaining the balance of pile-soil load distribution, improving the stability of the structure, and helping to extend the long-term performance and safety of the foundation structure.
[0021] 2. The vertical load transmitted by the anchor rod is converted into radial force and transmitted to the outer ring through the force transmission tube and several sets of radial stiffeners. When the load changes abruptly, the several sets of stiffeners can decompose part of the vertical impact force, thereby reducing the stress on the anchor rod. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a schematic diagram of the separation structure of this application; Figure 3 This is a schematic diagram of the pressure-bearing layer structure; Figure 4 This is a partial structural diagram of this application; Figure 5 for Figure 4 Enlarged structural diagram at point A in the middle.
[0023] In the diagram: 1. Underlying layer; 2. Soft soil layer; 4. Backfill layer; 401. First crushed stone layer; 402. Second crushed stone layer; 5. Elastic bearing layer; 501. Bearing plate; 502. Force transmission pipe; 503. Radial reinforcement; 504. Outer ring; 505. Conical reinforcement; 506. Reinforcing seat; 6. Cast-in-place raft slab; 7. Road surface layer; 8. Waterproof layer; 9. Anchor rod; 10. Anchor groove; 11. Vertical drainage pipe; 12. Horizontal drainage pipe; 13. Grouting hole; 14. Grouting branch pipe; 15. Groove; 16. Crushed stone geotextile cover; 1601. Horizontal reinforcement strip; 1602. Longitudinal reinforcement strip; 17. Woven layer. Detailed Implementation
[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0025] Reference Figure 1-5 The pile-raft composite foundation structure includes a lower layer 1, a soft soil layer 2 laid at the top of the lower layer 1, a backfill layer 4 above the soft soil layer 2, and a first crushed stone layer 401 laid at the top of the soft soil layer 2. An elastic bearing layer 5 is placed above the first crushed stone layer 401. A waterproof layer 8 is fixedly installed at the top of the soft soil layer 2. Several sets of anchor rods 9 are fixedly installed inside the elastic bearing layer 5, with the bottom ends of the anchor rods 9 extending into the interior of the soft soil layer 2. A second crushed stone layer 402 is laid above the elastic bearing layer 5. A raft slab 6 is fixedly installed above the second crushed stone layer 2. A road surface layer 7 is fixedly installed above the raft slab 6. An annular water collection trough is provided at the bottom of the second crushed stone layer 402. Several sets of vertical drainage pipes 11 are fixedly installed at the bottom of the second crushed stone layer 402 at the annular water collection trough. The bottom end of the vertical drainage pipes 11 extends to the bottom of the soft soil layer 2. A horizontal drainage pipe 12 is fixedly installed at the bottom end of the vertical drainage pipes 11 on the same side. An anchoring groove 10 matching several sets of anchoring rods 9 is opened at the bottom end of the raft slab 6. The top end of the anchoring rod 9 is engaged in the anchoring groove 10.
[0026] The upper load is longitudinally transferred to the soft soil layer 2 through several sets of anchor rods 9, and the load is distributed to the first crushed stone layer 401 and the second crushed stone layer 402 through the elastic bearing layer 5. The elastic bearing layer 5 is located between the first crushed stone layer 401 and the second crushed stone layer 402, which initially promotes uniform stress on the soil between the piles, which is beneficial to maintaining the service performance of the backfill layer 4. At the same time, by setting up an annular water collection trough, the water accumulated in the backfill layer 4 is drained through the vertical drainage pipe 11 and the horizontal drainage pipe 12. The horizontal drainage pipe 12 extends to the water collection channel on the outer wall, etc., so that the water can seep into the interior of the backfill layer 4. The water is drained to prevent the gravel particles from softening. At the same time, the waterproof layer 8 prevents water from seeping into the soft soil layer 2, thereby maintaining the balance of pile-soil load distribution, improving the stability of the structure, and helping to extend the long-term performance and safety of the foundation structure. The anchor rod 9 is connected to the cast raft slab 6 by mortise and tenon joints through the anchor groove 10. When the anchor rod 9 is subjected to horizontal load, it ensures the stability of the connection between the anchor rod 9 and the cast raft slab 6. At the same time, the load is directly transferred to the cast raft slab 6 through the anchor rod 9, which helps to reduce the stress on the backfill layer 4 and the elastic bearing layer 5.
[0027] Reference Figure 2-5The elastic bearing layer 5 includes a bearing plate 501, which is installed between the first crushed stone layer 401 and the second crushed stone layer 402. A force transmission tube 502 is fixedly installed on the outer surface of the anchor rod 9. The force transmission tube 502 is located inside the bearing plate 501. Several sets of radial reinforcing ribs 503 are fixedly installed on the outer periphery of the force transmission tube 502. An outer ring 504 is fixedly installed at the end of the several sets of radial reinforcing ribs 503 away from the force transmission tube 502. A tapered reinforcing rib 505 is fixedly installed on the outer surface of the anchor rod 9 directly below the force transmission tube 502. Several sets of reinforcing seats 506 are fixedly installed between the tapered reinforcing ribs 505 and the outer ring 504. The several sets of radial reinforcing ribs 503 are radially distributed along the outer periphery of the force transmission tube 502, and the several sets of reinforcing seats 506 are arranged in an inverted cone shape. The vertical load transmitted by the anchor rod 9 is converted into radial force and transmitted to the outer ring 504 through the force transmission tube 502 and several sets of radial stiffeners 503. When the load changes abruptly, several sets of reinforcing seats 506 can decompose part of the vertical impact force, thereby reducing the stress on the anchor rod 9. The concentrated load of the radial stiffeners 503 is evenly transmitted to the outer ring 504 radially through several sets of force transmission tubes 502, which improves the uniformity of load distribution. The several sets of reinforcing seats 506 are arranged in an inverted conical structure that is wider at the top and narrower at the bottom, forming a three-dimensional load transmission network, which can better transmit the load downward on the anchor rod 9.
[0028] Reference Figure 2-5 Both the upper and lower sides of the bearing plate 501 are provided with crushed stone geotextile sleeves 16. The crushed stone geotextile sleeves 16 include several sets of transverse reinforcing strips 1601 and longitudinal reinforcing strips 1602. The several sets of transverse reinforcing strips 1601 and longitudinal reinforcing strips 1602 are fixedly installed to the bearing plate 501, and the several sets of transverse reinforcing strips 1601 and longitudinal reinforcing strips 1602 are connected in a warp and weft direction. The top of the bearing plate 501 has several sets of grooves 15, and the bottom of the first crushed stone layer 401 is embedded in several sets of grooves 15. The several sets of transverse reinforcing strips 1601 and longitudinal reinforcing strips 1602 connected in a warp and weft direction can improve the quality of the bearing plate 501. The high bearing capacity of the bearing plate 501 is enhanced by its resistance to impact. The bottom of the first crushed stone layer 401 is tightly connected to the bearing plate 501 by embedding several sets of grooves 15. The crushed stone geotextile sleeve 16 further enhances the frictional bonding between the two. When subjected to upper load, the first crushed stone layer 401 can efficiently transfer the load to the bearing plate 501 through the grooves 15. At the same time, it avoids the problem of poor load transfer caused by relative sliding or separation between the first crushed stone layer 401 and the bearing plate 501, ensuring the stability of pile-soil load distribution and enhancing the overall performance of the foundation structure.
[0029] Reference Figure 1-3The anchor rod 9 has grouting holes 13 inside, and several sets of grouting branch pipes 14 are fixedly installed at the bottom of the anchor rod 9, and the grouting branch pipes 14 are connected to the anchor rod 9. The outer surfaces of the first crushed stone layer 401 and the second crushed stone layer 402 are both fixedly installed with braided layers 17. During construction, grout can be injected into the soil around the anchor rod 9 through the grouting holes 13. The grout diffuses into the surrounding soil through the grouting branch pipes 14, fills the soil pores, enhances the friction and adhesion between the soil and the anchor rod 9, and improves the anchoring effect. The braided layer 17 is made of high-strength polyester fiber. The braided layer 17 can evenly distribute the load acting on the crushed stone layer to a certain extent, and enhances the crushed stone layer's ability to resist the influence of external factors.
[0030] Working principle: The upper load is longitudinally transferred to the soft soil layer 2 through several sets of anchor rods 9. The load is then distributed to the first crushed stone layer 401 and the second crushed stone layer 402 through the elastic bearing layer 5, which is located between the first crushed stone layer 401 and the second crushed stone layer 402. This initially promotes uniform stress on the soil between the piles, which is beneficial for maintaining the serviceability of the backfill layer 4. At the same time, by setting up an annular water collection trough, the water accumulated in the backfill layer 4 is drained through vertical drainage pipes 11 and horizontal drainage pipes 12. The horizontal drainage pipes 12 extend to the outer wall water collection channel, etc. The water that has seeped into the backfill layer 4 is drained to prevent the gravel particles from softening. At the same time, the waterproof layer 8 prevents water from seeping into the soft soil layer 2, thereby maintaining the balance of pile-soil load distribution, improving the stability of the structure, and helping to extend the long-term performance and safety of the foundation structure. The vertical load transmitted by the anchor rod 9 is converted into radial force and transmitted to the outer ring 504 through the force transmission tube 502 and several sets of radial reinforcing bars 503. When the load changes suddenly, several sets of reinforcing seats 506 can decompose part of the vertical impact force, thereby reducing the stress on the anchor rod 9. Among them, the anchor rod 9 is connected to the cast raft slab 6 by mortise and tenon joint through the anchor groove 10. When the anchor rod 9 is subjected to horizontal load, it ensures the stability of the connection between the anchor rod 9 and the cast raft slab 6. At the same time, the load is directly transferred to the cast raft slab 6 through the anchor rod 9, which helps to reduce the stress on the backfill layer 4 and the elastic bearing layer 5. The concentrated load of the radial reinforcing rib 503 is evenly transferred to the outer ring 504 radially through several sets of force transmission tubes 502, which improves the uniformity of load distribution. Several sets of reinforcing seats 506 are set in an inverted conical structure with a wider top and a narrower bottom, forming a three-dimensional load transfer network, which can better transfer the load on the anchor rod 9 downward. Meanwhile, the cross reinforcement strips 1601 and longitudinal reinforcement strips 1602 connected in a warp and weft direction can improve the impact resistance of the bearing plate 501, thereby improving the bearing capacity of the bearing plate 501. During construction, grout can be injected into the soil around the anchor rod 9 through the grouting hole 13. The grout diffuses into the surrounding soil through the grouting branch pipe 14, filling the soil pores, enhancing the friction and adhesion between the soil and the anchor rod 9, and improving the anchoring effect. In addition, the bottom of the first crushed stone layer 401 is tightly connected to the bearing plate 501 by embedding several sets of grooves 15. The crushed stone geotextile sleeve 16 further enhances the frictional embedding between the two. When subjected to upper load, the first crushed stone layer 401 can efficiently transfer the load to the bearing plate 501 through the grooves 15. At the same time, it avoids the problem of poor load transfer caused by relative sliding or separation between the first crushed stone layer 401 and the bearing plate 501, ensuring the stability of pile-soil load distribution and enhancing the overall performance of the foundation structure. The woven layer 17 is made of high-strength polyester fiber. The woven layer 17 can evenly distribute the load acting on the crushed stone layer to a certain extent, enhancing the crushed stone layer's ability to resist the influence of external factors.
[0031] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A pile-raft composite foundation structure, comprising an underlying layer (1), characterized in that, The top of the lower layer (1) is covered with a soft soil layer (2), and a backfill layer (4) is provided above the soft soil layer (2). The backfill layer (4) includes a first crushed stone layer (401), which is laid on top of the soft soil layer (2). An elastic bearing layer (5) is provided above the first crushed stone layer (401). A waterproof layer (8) is fixedly installed on the top of the soft soil layer (2). Several sets of anchor rods (9) are fixedly installed inside the elastic bearing layer (5). The bottom end of the anchor rods (9) extends into the interior of the soft soil layer (2). A second crushed stone layer (402) is laid on top of the second crushed stone layer (402). A cast-in-place raft slab (6) is fixedly installed on top of the second crushed stone layer (402). A road surface layer (7) is fixedly installed on top of the cast-in-place raft slab (6). An annular water collection trough is provided at the bottom of the second crushed stone layer (402). Several sets of vertical drainage pipes (11) are fixedly installed at the bottom of the second crushed stone layer (402) at the annular water collection trough. The bottom end of the vertical drainage pipe (11) extends to the bottom of the soft soil layer (2). A horizontal drainage pipe (12) is fixedly installed at the bottom end of the vertical drainage pipe (11) on the same side.
2. The pile-raft composite foundation structure according to claim 1, characterized in that, The elastic bearing layer (5) includes a bearing plate (501), which is installed between the first crushed stone layer (401) and the second crushed stone layer (402). A force transmission tube (502) is fixedly installed on the outer surface of the anchor rod (9). The force transmission tube (502) is located inside the bearing plate (501). A number of radial reinforcing ribs (503) are fixedly installed on the outer periphery of the force transmission tube (502). An outer ring (504) is fixedly installed at one end of the radial reinforcing ribs (503) away from the force transmission tube (502). A tapered reinforcing rib (505) is fixedly installed on the outer surface of the anchor rod (9) directly below the force transmission tube (502). A number of reinforcing seats (506) are fixedly installed between the tapered reinforcing rib (505) and the outer ring (504).
3. The pile-raft composite foundation structure according to claim 1, characterized in that, The bottom end of the cast raft slab (6) is provided with an anchoring groove (10) that matches a number of anchoring rods (9), and the top end of the anchoring rod (9) is engaged in the anchoring groove (10).
4. The pile-raft composite foundation structure according to claim 2, characterized in that, Several sets of radial reinforcing ribs (503) are radially distributed along the outer circumferential surface of the force transmission tube (502), and several sets of reinforcing seats (506) are arranged in an inverted conical shape.
5. The pile-raft composite foundation structure according to claim 2, characterized in that, The pressure plate (501) is provided with crushed stone geotextile sleeves (16) on both the upper and lower sides. The crushed stone geotextile sleeves (16) include several sets of transverse reinforcing strips (1601) and longitudinal reinforcing strips (1602). The several sets of transverse reinforcing strips (1601) and longitudinal reinforcing strips (1602) are fixedly installed with the pressure plate (501), and the several sets of transverse reinforcing strips (1601) and longitudinal reinforcing strips (1602) are connected in the warp and weft directions.
6. The pile-raft composite foundation structure according to claim 1, characterized in that, The anchor rod (9) has a grouting hole (13) inside. Several sets of grouting branch pipes (14) are fixedly installed at the bottom of the anchor rod (9), and the grouting branch pipes (14) are connected to the anchor rod (9).
7. The pile-raft composite foundation structure according to claim 2, characterized in that, The top of the pressure plate (501) is provided with several sets of grooves (15), and the bottom of the first crushed stone layer (401) is embedded in several sets of grooves (15).
8. The pile-raft composite foundation structure according to claim 1, characterized in that, The outer surfaces of the first crushed stone layer (401) and the second crushed stone layer (402) are both fixedly fitted with a woven layer (17).