Anti-settling composite foundation of coastal house building
By adopting composite foundation structures in coastal housing construction, including concrete-core gravel piles, horizontally reinforced drainage cushion layers, and reinforced concrete raft foundations, the problem of easy settlement of coastal foundations has been solved, achieving high bearing capacity and stability of the foundation and reducing uneven settlement.
Patent Information
- Application Number
- CN202511862501.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-11
- Publication Date
- 2026-02-10
AI Technical Summary
The foundations of coastal areas are prone to settlement, which can lead to uneven settlement of buildings and affect their stability and safety.
The composite foundation structure includes a natural soft soil foundation, concrete core gravel piles, a horizontally reinforced drainage cushion layer, a seepage prevention and insulation layer, and a reinforced concrete raft foundation. The concrete core gravel piles reinforce the deep soft soil, the horizontally reinforced drainage cushion layer diffuses stress, the seepage prevention and insulation layer provides protection, and the reinforced concrete raft foundation uniformly transfers the load.
It significantly improves the bearing capacity and overall stability of the foundation, reduces uneven settlement, is suitable for coastal soft soil areas, and has good anti-settlement, drainage and durability performance.
Smart Images
Figure CN121496907A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite foundation technology, specifically to a settlement-resistant composite foundation for coastal buildings. Background Technology
[0002] The foundation of a building is the part of the building that is in direct contact with the soil. It is the basic system that supports the entire building structure. Its core function is to evenly transfer the weight (load) of the building to the underground soil or rock, ensuring the stability and safety of the building.
[0003] Coastal areas are typically soft soil zones with thick layers of silt or silty soil beneath the surface. The poor mechanical properties of this deep soft soil result in low foundation bearing capacity, making it easy for uneven settlement to occur when building houses directly on such foundations. Summary of the Invention
[0004] The purpose of this invention is to provide a settlement-resistant composite foundation for coastal buildings to solve the problem of settlement of foundations in coastal areas in the prior art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a settlement-resistant composite foundation for coastal housing construction, comprising a composite foundation body for overall support, wherein the composite foundation body comprises a natural soft soil foundation, and a plurality of concrete-core gravel piles are poured within the natural soft soil foundation to reinforce and drain the deep soft soil, and further comprising:
[0006] A horizontally reinforced drainage cushion layer is fixedly installed on top of a natural soft soil foundation to achieve effective stress diffusion in buildings and rapid drainage at the foundation. The horizontally reinforced drainage cushion layer includes a geotextile laid on the natural soft soil foundation. The geotextile acts as an isolation and filter, preventing the infiltration of upper particles and allowing water to flow through. A geogrid is also laid on the geotextile. The geogrid provides tensile strength, restrains the cushion layer material, and enhances the overall integrity.
[0007] A seepage-proof and heat-insulating layer is fixedly installed on top of the geogrid and is used to protect the bottom of the building from moisture, salt and alkali corrosion, and heat insulation. The seepage-proof and heat-insulating layer includes a protective plate fixedly installed on the geogrid.
[0008] A reinforced concrete raft foundation is fixedly installed on top of a protective slab to uniformly transfer the load of the superstructure downwards to the entire composite foundation. The reinforced concrete raft foundation includes a reinforced concrete raft slab cast on the protective slab.
[0009] Furthermore, the main body of the composite foundation also includes an anti-settlement top plate fixedly installed on the top of the concrete core gravel piles. The anti-settlement top plate is used to expand the load-bearing area of the pile top, prevent the pile head from penetrating the upper structure, and coordinate the load-bearing of each pile. In addition, several pre-embedded steel bars are cast inside the concrete core gravel piles and the anti-settlement top plate to significantly enhance their vertical bearing capacity and structural integrity. Several pre-embedded steel bars are also cast inside the anti-settlement top plate to further improve the bending stiffness and lateral load distribution capacity of the anti-settlement top plate.
[0010] Furthermore, the composite foundation body also includes several pile-interval soils filled within the natural soft soil foundation and located on the sides of several concrete-core sand and gravel piles. The pile-interval soils are composed of medium-coarse sand and gravel, used to compact the soft soil around the piles and, together with the concrete-core sand and gravel piles, form a vertical drainage channel network to accelerate the consolidation process of the soft soil foundation.
[0011] Furthermore, the horizontally reinforced drainage cushion layer also includes a sand and gravel cushion layer laid on the geotextile and filled between the geogrid grids. The sand and gravel cushion layer and the geogrid together form a solid and flat working surface and serve as the main horizontal drainage layer.
[0012] Furthermore, the materials of the seepage-proof and heat-insulating layers are polyethylene film, polyvinyl chloride rolls, or extruded polystyrene boards; wherein, the polyethylene film or polyvinyl chloride rolls mainly serve to prevent seepage and block capillary water, while the extruded polystyrene boards mainly provide heat insulation performance, prevent frost heave, and improve the building's energy-saving effect.
[0013] Furthermore, the material of the reinforced concrete raft foundation is reinforced concrete, and it is distributed in a mesh pattern at the bottom of the building to form an integral foundation slab with high rigidity and strength, which can effectively adjust and resist differential settlement.
[0014] Furthermore, the concrete-core sand and gravel pile includes an internal precast reinforced concrete core pile and an outer sand and gravel shell; the precast reinforced concrete core pile provides the main vertical support force and bending stiffness, transferring the load to the deep stable soil layer, while the sand and gravel shell provides significant lateral friction resistance and serves as an efficient vertical drainage channel.
[0015] Furthermore, the sand and gravel cushion layer comprises medium-coarse sand and crushed stone, wherein the particle size of the crushed stone is 20-40mm; this gradation design ensures that the cushion layer has good permeability to achieve rapid drainage, while having sufficient compressive strength and interlocking effect to achieve effective stress diffusion.
[0016] Compared with existing technologies, this invention provides a settlement-resistant composite foundation for coastal buildings. This structure mainly consists of a composite foundation body, a horizontally reinforced drainage cushion layer, a seepage-proof and insulation layer, and a reinforced concrete raft foundation. The composite foundation body is based on natural soft soil and contains several concrete-core gravel piles with anti-settlement slabs on top. The spaces between the piles are filled with gravel to enhance drainage and compaction. The horizontally reinforced drainage cushion layer, composed of geotextile and geogrid, serves to diffuse stress and facilitate drainage. The seepage-proof and insulation layer uses materials such as polyethylene film or extruded polystyrene board, providing moisture-proof and insulation functions. The top reinforced concrete raft foundation evenly transfers the building load to the lower structure. This composite foundation, through multi-layered synergy, effectively improves the bearing capacity and overall stability of the foundation, significantly reduces uneven settlement, and is suitable for coastal soft soil areas, exhibiting excellent settlement prevention, drainage, and durability performance. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.
[0018] Figure 1 This is a schematic diagram of the overall structure of the composite foundation provided in an embodiment of the present invention;
[0019] Figure 2 This is a schematic diagram of a concrete core gravel pile structure provided in an embodiment of the present invention;
[0020] Figure 3 This is a diagram illustrating the concrete core gravel pile structure provided in an embodiment of the present invention.
[0021] Figure 4 This is a distribution diagram of the composite foundation structure provided in an embodiment of the present invention;
[0022] Figure 5 Provided for embodiments of the present invention Figure 1 Schematic diagram of the structure at point A in the middle;
[0023] Figure 6 A cross-sectional view of a concrete core gravel pile structure provided in an embodiment of the present invention.
[0024] Explanation of reference numerals in the attached figures:
[0025] 1. Natural soft soil foundation; 2. Concrete core gravel piles; 3. Soil between piles; 4. Anti-settlement top slab; 5. Geotextile; 6. Geogrid; 7. Protective board; 8. Reinforced concrete raft slab; 9. Embedded steel bar one; 10. Embedded steel bar two. Detailed Implementation
[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.
[0027] As attached Figure 1 To be continued Figure 6 As shown:
[0028] Example 1:
[0029] This invention provides a settlement-resistant composite foundation for coastal housing construction, comprising a composite foundation body for overall support, the composite foundation body including a natural soft soil foundation 1, within which several concrete-core gravel piles 2 are poured; a horizontally reinforced drainage cushion layer, fixedly installed on top of the natural soft soil foundation 1, for stress diffusion and bottom drainage of the building, the horizontally reinforced drainage cushion layer including geotextile 5 laid on the natural soft soil foundation 1, and a geogrid 6 laid on the geotextile 5; a seepage-proof and heat-insulating layer, fixedly installed on top of the geogrid 6, for bottom protection of the building, the seepage-proof and heat-insulating layer including a protective plate 7 fixedly installed on the geogrid 6; and a reinforced concrete raft foundation, fixedly installed on top of the protective plate 7, for transferring the protective load downwards, the reinforced concrete raft foundation including a reinforced concrete raft slab 8 poured on the protective plate 7.
[0030] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 The main body of the composite foundation includes a natural soft soil foundation 1, concrete core gravel piles 2, anti-settlement top slab 4, and soil between piles 3;
[0031] Several concrete-core sand and gravel piles 2 are poured inside the natural soft soil foundation 1. The concrete-core sand and gravel piles 2 are composed of an internal precast reinforced concrete core pile and an external crushed stone or sand and gravel shell. The internal precast reinforced concrete core pile provides extremely high vertical compressive strength and bending stiffness, which can directly transfer the building load to the deeper and harder soil layer. The sand and gravel shell on the outside of the concrete-core sand and gravel piles 2 provides huge lateral friction resistance and serves as a vertical drainage channel, accelerating the consolidation and drainage of the soft soil around the piles, so that the settlement is completed quickly and stabilized. Furthermore, the sides of the concrete-core sand and gravel piles 2 inside the natural soft soil foundation 1 are filled with inter-pile soil 3, which includes medium and coarse sand and crushed stone. The sand and gravel are filled into the soil by means of vibratory pipe driving, etc., to compact the surrounding soft soil and form drainage channels, thereby improving the drainage of the natural soft soil foundation 1.
[0032] Meanwhile, an anti-settlement slab 4 is poured on top of the concrete core gravel pile 2. When several concrete core gravel piles 2 are poured into the natural soft soil foundation 1, the anti-settlement slab 4 on top of the concrete core gravel piles 2 can increase the protective capacity of the top of the concrete core gravel piles 2, thereby improving the anti-settlement performance of the concrete core gravel piles 2. This makes the houses in coastal areas safer and more stable during construction and use. Several pre-embedded steel bars 9 are poured inside both the concrete core gravel piles 2 and the anti-settlement slab 4, thereby improving the vertical support force of the concrete core gravel piles 2 and the anti-settlement slab 4. Several pre-embedded steel bars 10 are also poured inside the anti-settlement slab 4, so that the pre-embedded steel bars 10 can improve the lateral support force of the anti-settlement slab 4, that is, improve the anti-settlement capacity of the anti-settlement slab 4 and the concrete core gravel piles 2.
[0033] refer to Figure 1 and Figure 5 The composite foundation consists of a natural soft soil foundation 1, concrete core gravel piles 2, an anti-settlement top slab 4, and soil between piles 3. Several concrete core gravel piles 2 arranged in a quincunx or rectangular pattern are poured inside the natural soft soil foundation 1. The pile spacing is usually 3-5 times the pile diameter, depending on the bearing capacity requirements of the foundation. The concrete core gravel piles 2 are composed of an internal precast reinforced concrete core pile and an outer crushed stone or gravel shell. The diameter of the precast reinforced concrete core pile is generally 300-500mm, and the strength grade is not lower than C30. It can provide extremely high vertical compressive strength (up to 500kPa or more) and bending stiffness, directly transferring the building load to the deeper, harder soil layer. The thickness of the gravel shell around the concrete core gravel piles 2 is 150-250mm. It uses well-graded crushed stone or gravel, which not only provides huge lateral friction resistance for the pile body, but also serves as a vertical drainage channel, greatly accelerating the consolidation and drainage of the soft soil around the pile, so that the post-construction settlement is completed and stabilized in a short time.
[0034] Meanwhile, within the natural soft soil foundation 1, the sides of several concrete core sand and gravel piles 2 are filled with inter-pile soil 3. The inter-pile soil 3 is a mixture of medium-coarse sand and 5-40mm continuously graded crushed stone. The sand and gravel are squeezed into the soil through processes such as vibratory pipe driving and tamping, which effectively compacts the surrounding soft soil and improves its physical and mechanical properties. At the same time, it forms a three-dimensional drainage channel network together with the concrete core sand and gravel piles 2, which significantly improves the drainage and consolidation efficiency within the natural soft soil foundation 1.
[0035] Secondly, a 200-300mm thick anti-settlement top plate 4 is poured on top of the concrete core gravel pile 2. This top plate is made of C25 or higher grade concrete, which can effectively expand the bearing area, prevent the pile head from penetrating the upper cushion layer, and coordinate the force of the pile group. Pre-embedded steel bars 9 are set inside the concrete core gravel pile 2 and the anti-settlement top plate 4. The steel bars are HRB400 grade steel bars with a diameter of 16-25mm and a length that runs through the entire component, which significantly enhances its vertical bearing capacity and structural integrity. Pre-embedded steel bars 10 are also set inside the anti-settlement top plate 4. The steel bars are HRB400 grade steel bars with a diameter of 12-16mm and are arranged in both directions at a spacing of 150-200mm to form a steel mesh, which effectively improves the bending stiffness and lateral load distribution capacity of the anti-settlement top plate 4.
[0036] Example 2:
[0037] refer to Figure 1 and Figure 4 The horizontally reinforced drainage cushion layer includes geotextile 5 and geogrid 6;
[0038] By laying geotextile 5 on the top of the natural soft soil foundation 1 and several anti-settlement slabs 4, the geotextile 5 can prevent the sand and gravel of the cushion layer from sinking into the underlying soft soil, and also ensure that water can pass through without the soil particles being carried away. Geogrid 6 is laid on the geotextile 5, which can greatly improve the tensile strength and integrity of the cushion layer, constrain the sand and gravel like a "net", more effectively spread the concentrated load at the top of the pile to a larger area, and force the pile and the soil between the piles 3 to work together, significantly reducing uneven settlement.
[0039] Meanwhile, a sand and gravel cushion layer is laid above the geotextile 5 between the geogrids 6. The sand and gravel are medium-coarse sand and uniformly sized crushed stone with a diameter of 20-40mm. This allows the sand and gravel cushion layer to work with the geogrids 6 to form a flat and solid construction surface. It also serves as a horizontal drainage layer, directing water from the upper foundation and the vertical reinforcement to the drainage system around the site, accelerating the consolidation of the foundation, and evenly transferring the concentrated load from the foundation slab to the piles and the soil between the piles 3 below, preventing stress concentration.
[0040] refer to Figure 1 and Figure 4 The seepage prevention and insulation layer includes the protective plate 7, and the reinforced concrete raft foundation includes the reinforced concrete raft 8.
[0041] By laying a protective board 7 on top of the geogrid 6, the protective board 7 can be selected according to the actual conditions of the coastal area. When the main function is moisture protection, the material of the protective board 7 is preferably polyethylene film (PE) and polyvinyl chloride roll (PVC), which can block the rise of underground capillary water, prevent moisture from penetrating the upper concrete foundation structure and walls, and avoid dampness and salt corrosion. When the main function is heat preservation, the material of the protective board 7 can be extruded polystyrene board, which can prevent the foundation soil from freezing and heave and causing damage to the building, reduce the loss of indoor heat to the foundation, and improve the energy-saving and heat preservation effect.
[0042] Meanwhile, a reinforced concrete raft slab 8 is poured on top of the protective plate 7. The reinforced concrete raft slab 8 is a reinforced concrete structure, which allows the reinforced concrete raft slab 8 to act like a huge tray, converting the concentrated load of the wall and column into a uniformly distributed load, and then transferring it to the composite foundation body below. Its own stiffness and strength can further adjust and resist uneven settlement.
[0043] refer to Figure 1 , Figure 4 and Figure 5 By laying long-filament geotextile 5 with a strength of 400g / m² or more on top of the natural soft soil foundation 1 and several anti-settlement slabs 4, the geotextile effectively prevents the sand and gravel of the cushion layer from sinking into the underlying soft soil. Its good reverse filtration properties also ensure that pore water can pass through smoothly without soil particles being carried away. A bidirectional geogrid 6 with a tensile strength of not less than 50kN / m is laid on the geotextile 5. The geogrid 6 can greatly improve the tensile strength and integrity of the cushion layer. Through the interlocking effect of its mesh structure and filling material, the concentrated load at the top of the pile can be effectively diffused to a larger area. The load diffusion angle can reach 30-40°, and the pile and the soil between the piles 3 are forced to work together to control the differential settlement within the allowable range.
[0044] Meanwhile, a 300-500mm thick sand and gravel cushion layer is laid above the geotextile 5 and between the grids of the geogrid 6. The sand and gravel cushion layer is made of medium-coarse sand with uniform particle size and hard texture and crushed stone with a particle size of 20-40mm mixed in a ratio of 1:1-1:2, with a compaction degree of not less than 0.95. This cushion layer and the geogrid 6 together form a flat and solid working platform with a horizontal permeability coefficient of more than 1×10⁻²cm / s. It can quickly guide the pore water discharged from the upper foundation and vertical reinforcement to the blind ditch or collection well system around the site. At the same time, its high deformation modulus (usually greater than 30MPa) can effectively transfer the load from the foundation plate to the underlying pile-soil composite foundation, avoiding stress concentration.
[0045] Secondly, a seepage-proof and heat-insulating layer including a protective board 7 is set up, and a reinforced concrete raft foundation including a reinforced concrete raft 8 is constructed. The protective board 7 is laid on top of the geogrid 6. When the main requirements of the project are moisture-proof and salt-alkali-proof, a polyethylene film (PE) or polyvinyl chloride roll (PVC) with a thickness of not less than 0.8mm is used. The joints are hot-melt welded and the overlap width is not less than 100mm to form a complete seepage barrier. When heat insulation is the main consideration, an extruded polystyrene board (XPS) with a thickness of 50-100mm and a compressive strength of not less than 250kPa is used. The gaps between the boards are sealed with special tape.
[0046] In addition, a reinforced concrete raft slab 8 with a thickness of 300-600mm is poured on top of the protective slab 7. The concrete strength grade is not lower than C30, and the reinforcement ratio is controlled between 0.15% and 0.25%. The raft slab is equipped with a double-layer bidirectional steel mesh. The upper reinforcement resists negative bending moment, and the lower reinforcement bears positive bending moment, forming a slab with high stiffness (elastic modulus exceeding 3×10⁻⁶). 4 The raft foundation (MPa) can redistribute the column and wall loads of the superstructure, transforming local pressure into uniform stress and transferring it to the lower composite foundation. Its own stiffness and strength can effectively adjust the distribution of base reaction force and resist uneven settlement caused by uneven load or soil layer changes.
[0047] Example 3:
[0048] refer to Figure 1 , Figure 4 , Figure 5 and Figure 6 After the site is leveled, the construction of concrete core sand and gravel pile 2 is carried out first. The vibratory pipe driving method is adopted. The diameter of the pile pipe is consistent with the design pile diameter. The driving depth should penetrate the soft soil layer and enter the lower relatively hard layer by at least 1m. The precast reinforced concrete core pile is prefabricated in the factory and cured for no less than 28 days. After being transported to the site, it is vertically hoisted into the pile hole and positioned. Then, crushed stone with a particle size of 5-40mm is filled in layers around the core pile. The vibratory hammer is used to vibrate and pull the pipe at the same time. Every 1-2m of pipe pulling is paused and vibrated for 10-20 seconds to ensure the compaction of the crushed stone and form a dense sand and gravel shell. The top elevation of the pile is controlled 0.5m above the design elevation. After the pile is completed, it is leveled to the bottom elevation of the anti-settlement top plate 4.
[0049] Meanwhile, the anti-settlement top plate 4 is set up on site and poured as a whole with the pile core. Before pouring, the laitance and loose material on the top of the concrete core sand and gravel pile 2 are removed to expose the solid concrete surface. The pre-embedded steel bar 19 is welded or mechanically connected to the main reinforcement of the pile core, and the connection length is not less than 10 times the diameter of the steel bar. The pre-embedded steel bar 20 is tied into a net according to the design spacing and firmly tied to the pre-embedded steel bar 19. After the formwork is installed, C30 micro-expansion concrete is poured and fully vibrated with an immersion vibrator to ensure that the concrete is dense and well bonded to the lower pile body. After pouring, it is covered and cured for no less than 7 days.
[0050] Secondly, during the construction of the horizontal reinforced drainage cushion layer, the geotextile 5 should be laid flat and without wrinkles, with an overlap width of not less than 300mm. When laying the geogrid 6, its main strength direction should be consistent with the main stress direction, with an overlap width of not less than 200mm and fixed with special connectors. The sand and gravel cushion layer should be laid and compacted in layers, with each layer having a loose thickness of not more than 300mm. It should be compacted 2-3 times with a static roller to ensure that the design compaction degree is achieved.
[0051] In addition, during the construction of the seepage prevention and insulation layer, if roll-type seepage prevention materials are used, the base layer must be flat and dry. The long side overlap of the roll material should be no less than 80mm, and the short side overlap should be no less than 100mm. If XPS insulation board is used, the boards should be laid in a staggered manner with tight joints. When the uppermost reinforced concrete raft slab 8 is poured, a post-pouring strip should be set to reduce temperature shrinkage stress, and settlement observation points should be pre-embedded to monitor the foundation settlement in the later stage.
[0052] Working principle: The construction and use of anti-settlement composite foundations for coastal buildings begins with the treatment of the natural soft soil foundation 1. First, several concrete-core sand and gravel piles 2 are poured inside the natural soft soil foundation 1 using methods such as vibratory pipe driving. The core is provided with vertical support by precast reinforced concrete core piles, while the outer sand and gravel shell provides lateral friction resistance and serves as a vertical drainage channel, accelerating the consolidation of the soft soil. The gaps between the piles are filled with inter-pile soil 3 composed of medium-coarse sand and gravel, further compacting the soil and forming a network of drainage paths. Subsequently, A settling-resistant top slab 4 is poured on top of the concrete-core gravel pile 2, and the vertical and horizontal support forces are enhanced by the pre-embedded steel bars 9 and 10 inside, forming a stable pile cap system that effectively prevents pile head penetration and coordinates the force of the pile group. On this basis, a horizontally reinforced drainage cushion layer is laid on top of the natural soft soil foundation 1 and the settling-resistant top slab 4: first, geotextile 5 is laid to isolate and filter, preventing the upper gravel from sinking and allowing water to flow through; then, geogrid 6 is laid, and the spaces between its grids are filled with a gravel cushion layer, together forming a complete structure. A high-tensile-strength, integral horizontal drainage and stress diffusion layer evenly transfers the upper load to the piles (concrete-core gravel piles 2) and soil (soil between piles 3) below, forcing them to work together and significantly reducing uneven settlement. Next, a protective board 7, providing impermeability and insulation, is laid on top of the cushion layer. Depending on the coastal environment, either polyethylene film (moisture-proof and salt-alkali-proof) or extruded polystyrene board (insulating and frost-resistant) is selected to protect the superstructure. Finally, a reinforced concrete raft foundation 8 is poured at the very top, forming the overall reinforced concrete raft foundation. It acts like a rigid tray, transforming the concentrated loads of the upper walls and columns into uniformly distributed loads, and safely transferring them to the entire composite foundation structure below. The entire foundation, through a multi-layered and collaborative working mechanism, from deep drainage and reinforcement (concrete core sand and gravel piles 2, soil between piles 3) to mid-layer stress diffusion and drainage (horizontal reinforced drainage cushion layer), and then to surface protection and load distribution (protective plate 7, reinforced concrete raft slab 8), ultimately achieves effective control over the settlement of coastal soft soil foundations, especially uneven settlement, ensuring the long-term stability and safety of buildings.
[0053] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.
Claims
1. A type of anti-settlement composite foundation for coastal buildings, comprising a composite foundation body for overall support, wherein the composite foundation body comprises a natural soft soil foundation (1), and a plurality of concrete-core gravel piles (2) are poured into the natural soft soil foundation (1), characterized in that, Also includes: A horizontally reinforced drainage cushion layer is fixedly installed on the top of the natural soft soil foundation (1) for the purpose of stress diffusion and bottom drainage of the building. The horizontally reinforced drainage cushion layer includes a geotextile (5) laid on the natural soft soil foundation (1), and a geogrid (6) is also laid on the geotextile (5). The seepage prevention and insulation layer is fixedly installed on the top of the geogrid (6) for the protection of the bottom of the house. The seepage prevention and insulation layer includes a protective plate (7) fixedly installed on the geogrid (6). A reinforced concrete raft foundation is fixedly installed on the top of the protective plate (7) to transfer the protective load downwards. The reinforced concrete raft foundation includes a reinforced concrete raft slab (8) poured on the protective plate (7).
2. The anti-settlement composite foundation for coastal housing construction according to claim 1, characterized in that, The composite foundation also includes a settling-proof top plate (4) fixedly installed on the top of the concrete core sand and gravel pile (2); Furthermore, the concrete core sand and gravel pile (2) and the anti-settlement top plate (4) are both filled with a number of pre-embedded steel bars (9), and the anti-settlement top plate (4) is also filled with a number of pre-embedded steel bars (10).
3. The anti-settlement composite foundation for coastal housing construction according to claim 2, characterized in that, The composite foundation also includes several inter-pile soils (3) filled in the natural soft soil foundation (1) and located on the sides of several concrete core sand and gravel piles (2).
4. The anti-settlement composite foundation for coastal housing construction according to claim 1, characterized in that, The horizontally reinforced drainage cushion layer also includes a sand and gravel cushion layer laid on the geotextile (5) and located between the geogrids (6).
5. The anti-settlement composite foundation for coastal housing construction according to claim 1, characterized in that, The materials for the waterproof and heat-insulating layers are polyethylene film, polyvinyl chloride rolls, or extruded polystyrene boards.
6. The anti-settlement composite foundation for coastal housing construction according to claim 1, characterized in that, The reinforced concrete raft foundation is made of reinforced concrete and is distributed in a mesh pattern at the bottom of the building.
7. The anti-settlement composite foundation for coastal housing construction according to claim 2, characterized in that, The concrete core sand and gravel pile (2) includes an internal precast reinforced concrete core pile and an outer sand and gravel shell.
8. The anti-settlement composite foundation for coastal housing construction according to claim 4, characterized in that, The sand and gravel cushion layer includes medium-coarse sand and crushed stone, wherein the particle size of the crushed stone is 20-40mm.