Combined anti-floating drainage device and stability calculation method thereof

Abstract

The invention discloses a combined anti-floating drainage device and a stability calculation method thereof, and relates to the technical field of building anti-floating drainage devices.The combined anti-floating drainage device comprises uplift pile body assemblies and pressure relief drainage mechanisms, and at least one uplift pile body assembly and at least one pressure relief drainage mechanism are arranged on a building bottom plate in a staggered mode; the upper end of the uplift pile body assembly is poured on a building bottom plate, the lower end of the uplift pile body assembly is pre-buried underground, and the pressure relief and drainage mechanism can relieve pressure of seepage water below the building bottom plate. The anti-floating and anti-seepage effects of an underground building structure can be improved, potential safety hazards of buildings caused by water seepage are reduced, the service life is prolonged, and sustainable development of urban underground space is promoted; the problems of pile-soil interface leakage, insufficient bearing capacity exertion, insufficient long-term durability and the like in traditional uplift pile construction in a high-water-level foundation can be solved, and effective combination of the bearing performance and the anti-seepage function of the uplift pile is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of building anti-buoyancy drainage devices, and in particular to a combined anti-buoyancy drainage device and its stability calculation method. Background Technology

[0002] With the acceleration of urbanization and the continuous expansion of underground space development, underground structures typically consist of a base slab, a concrete cushion layer, and a permeable sand layer from top to bottom. The concrete cushion layer effectively bears the load applied by the superstructure and evenly distributes the load across the foundation, preventing localized stress concentration and thus protecting the foundation from damage. The permeable sand layer reduces the pressure of water on the underground structure and utilizes the permeability of water to assist in drainage. As the burial depth of underground structures generally increases, the issue of buoyancy resistance becomes increasingly prominent.

[0003] Currently, anti-buoyancy technologies for underground engineering are mainly divided into two categories: passive anti-buoyancy and active anti-buoyancy. Passive anti-buoyancy technologies mainly include anti-uplift piles, counterweight methods, and anti-buoyancy anchors. These technologies balance the buoyancy force by increasing the self-weight of the structure or the anchoring force. Active anti-buoyancy technologies, on the other hand, are based on interception and pressure reduction, and achieve anti-buoyancy by reducing the water pressure under the bottom plate of the structure.

[0004] Despite some progress in anti-buoyancy technology, problems such as drainage system clogging and insufficient durability still exist in practical engineering applications. Therefore, there is an urgent need to develop an underground combined anti-buoyancy and seepage prevention system that integrates efficient drainage, effective anti-buoyancy, and stability assessment. Summary of the Invention

[0005] The purpose of this invention is to provide a combined anti-buoyancy drainage device to solve the problems existing in the prior art, effectively improve the anti-buoyancy and seepage prevention effect of underground buildings, and enhance the safety performance of actual engineering projects.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a combined anti-buoyancy drainage device, including an anti-uplift pile assembly and a pressure relief drainage mechanism. At least one set of the anti-uplift pile assembly and at least one pressure relief drainage mechanism are staggered on the building base plate. The upper end of the anti-uplift pile assembly is cast on the building base plate and the lower end is embedded in the ground. The pressure relief drainage mechanism can relieve the pressure of seepage water below the building base plate.

[0007] Preferably, the anti-uplift pile assembly includes a horizontal reinforcing plate and a vertical anchor pile, which are connected as a whole by casting. The center of the vertical anchor pile is connected to the center of the horizontal reinforcing plate. The horizontal reinforcing plate is cast in the building's base slab, and the vertical anchor pile is pre-embedded underground.

[0008] Preferably, the horizontal stiffening plate includes several horizontal bars and stirrups arranged in the horizontal direction, the stirrups being tied to the horizontal bars at equal intervals, and the horizontal stiffening plate being a cast-in-place reinforced concrete component.

[0009] Preferably, the vertical anchor pile includes several longitudinal bars and stirrups arranged in the vertical direction, the stirrups being tied to the longitudinal bars at equal intervals, and the vertical anchor pile being a cast-in-place reinforced concrete component.

[0010] Preferably, the surface of the vertical anchor pile is coated with a waterproof coating; at least one anchor bar is provided through the center of the horizontal stiffening plate and the vertical anchor pile.

[0011] Preferably, the pressure relief drainage mechanism includes a water collection well, a pressure relief pool, a pressure relief pipe, and a pressure relief valve. The pressure relief pool is located in a permeable sand layer below the building's foundation slab and its bottom and side walls are permeable. The water collection well is located on a concrete pad below the building's foundation slab and its top is open. A sealing partition is provided between the top of the pressure relief pool and the bottom of the water collection well. The pressure relief pipe passes through the sealing partition to connect the pressure relief pool and the water collection well. The pressure relief valve is provided at the outlet end of the pressure relief pipe.

[0012] Preferably, the sidewall of the pressure relief pool is constructed of permeable bricks, allowing seepage water from the permeable sand layer to collect within the pressure relief pool.

[0013] Preferably, the water collection well is equipped with a water level sensor and a drainage component. Both the water level sensor and the drainage component are communicatively connected to a controller. When the liquid level in the water collection well reaches a set level, the controller can control the drainage component to discharge the water in the water collection well into the municipal drainage channel. The drainage component includes a drainage pump, a drainage pipe, and a drainage valve. The drainage pump is installed in the water collection well and is connected to the municipal drainage channel through the drainage pipe. A drainage valve is installed on the drainage pipe.

[0014] Preferably, the pressure relief pool is connected to at least one drainage channel, and a gravel filter layer and a geotextile are sequentially arranged above the drainage channel, with the geotextile laid below the permeable sand layer.

[0015] This invention also discloses a method for calculating the anti-buoyancy stability of the above-mentioned combined anti-buoyancy drainage device, which specifically includes the following steps: S1, Calculate the buoyancy force. The calculation of the buoyancy force on the building structure is as follows. Among them, F fk —The buoyancy force on the building structure, γ W —The density of water, AW —The cross-sectional area of ​​the building structure below the groundwater level. L – Length of the building structure; S2, the buoyancy resistance of a building structure mainly includes the structure's own weight, the self-weight of the pull-out piles, and their pull-out bearing capacity. The structure's own weight is calculated as follows. Among them, G K —The building structure's own weight, γ — The structural weight of the building. A – Cross-sectional area of ​​the building structure below the groundwater level. L – Length of the building structure; The self-weight of the tension pile is calculated as follows: Among them, G P —The self-weight of the anti-uplift pile, γ — density of the tension pile V – Volume of the tension pile The bearing capacity of the tension pile is calculated as follows: Where, N K —Bearing capacity of tension piles T K —Standard value of ultimate tensile bearing capacity when the tensile pile fails as a whole. G P —The self-weight of the anti-uplift pile; S3. The anti-buoyancy stability of the building structure shall meet the following requirements. K – Stability coefficient of the building structure K w —The safety factor for the buoyancy resistance of the building structure (the value is determined according to the actual situation, usually 1.05-1.20); S4. Based on the self-weight of all structures above the pile foundation and the buoyancy resistance of the pile foundation, determine the buoyancy bearing capacity of the passive measures, and thereby define the pressure-limiting water level. Where h is the pressure-limiting water level. F – Anti-buoyancy force A – Area of ​​the foundation slab γ W —The density of water.

[0016] The present invention achieves the following technical effects compared to the prior art: This invention can improve the anti-buoyancy and seepage prevention effect of underground building structures, reduce building safety hazards caused by water seepage, extend service life, and help the sustainable development of urban underground space; it can solve the problems of pile-soil interface leakage, insufficient bearing capacity and insufficient long-term durability in the construction of traditional anti-tension piles in high water level foundations, and achieve an effective combination of anti-tension pile bearing performance and seepage prevention function. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the combined anti-buoyancy drainage device in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the calculation principle of the anti-buoyancy stability of the combined anti-buoyancy drainage device in this embodiment of the invention. In the diagram: 1-Horizontal reinforcing plate, 2-Vertical anchor pile, 3-Horizontal reinforcement, 4-Longitudinal reinforcement, 5-Stirrup, 6-Anchor reinforcement, 7-Waterproof coating, 8-Water collection well, 9-Pressure relief pool, 10-Pressure relief pipe, 11-Pressure relief valve, 12-Drainage channel, 13-Building base slab, 14-Concrete cushion layer, 15-Permeable sand layer, 16-Water level sensor, 17-Drainage pump, 18-Drainage pipe, 19-Geotextile, 20-Gravel filter layer. Detailed Implementation

[0019] 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 only some 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.

[0020] It should be noted that in the description of this invention, the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "clockwise," and "counterclockwise," etc., indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," "third," and "fourth" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] The purpose of this invention is to provide a combined anti-buoyancy drainage device to solve the problems existing in the prior art, effectively improve the anti-buoyancy and seepage prevention effect of underground buildings, and enhance the safety performance of actual engineering projects.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1 like Figure 1As shown, this embodiment provides a combined anti-buoyancy drainage device, including an anti-tension pile assembly and a pressure relief drainage mechanism. At least one set of anti-tension pile assemblies and at least one pressure relief drainage mechanism are staggered on the building base slab 13. The upper end of the anti-tension pile assembly is cast on the building base slab 13, and the lower end is pre-embedded underground. The pressure relief drainage mechanism can relieve pressure on the seepage water below the building base slab 13. This embodiment can improve the anti-buoyancy and seepage prevention effect of underground building structures, reduce building safety hazards caused by seepage, extend service life, and contribute to the sustainable development of urban underground space. By using the anti-tension pile assembly and the pressure relief drainage mechanism, the problems of pile-soil interface leakage, insufficient bearing capacity, and insufficient long-term durability in the construction of traditional anti-tension piles in high-water-level foundations can be solved, achieving an effective combination of the bearing capacity and seepage prevention function of the anti-tension pile.

[0025] As an optional solution, in this embodiment, the anti-uplift pile assembly includes a horizontal stiffening plate 1 and a vertical anchor pile 2. The horizontal stiffening plate 1 and the vertical anchor pile 2 are connected as one unit by casting. The center of the vertical anchor pile 2 is connected to the center of the horizontal stiffening plate 1. The horizontal stiffening plate 1 is cast in the building base slab 13, and the vertical anchor pile 2 is pre-embedded in the ground to form an anti-uplift pile.

[0026] As an optional solution, in this embodiment, the horizontal stiffening plate 1 includes several horizontal bars 3 and stirrups 5 arranged in the horizontal direction. The stirrups 5 are tied to the horizontal bars 3 at equal intervals. The horizontal stiffening plate 1 is a cast-in-place reinforced concrete component with a size of 400mm×200mm.

[0027] As an optional solution, in this embodiment, the vertical anchor pile 2 includes several longitudinal bars 4 and stirrups arranged in the vertical direction. The stirrups 5 are tied to the longitudinal bars 4 at equal intervals. The vertical anchor pile 2 is a cast-in-place reinforced concrete component with a diameter of about 300mm and a length of about 6m-8m.

[0028] As an optional solution, in this embodiment, the surface of the vertical anchor pile 2 is coated with a waterproof coating 7, which is a 2mm-3mm thick polymer cement coating; at least one anchor bar 6 is provided through the center of the horizontal stiffening plate 1 and the vertical anchor pile 2 to strengthen the connection between the horizontal stiffening plate 1 and the vertical anchor pile 2 and the ground.

[0029] As an optional solution, the pressure relief drainage mechanism in this embodiment includes a sump 8, a pressure relief pool 9, a pressure relief pipe 10, and a pressure relief valve 11. The pressure relief pool 9 is located in the permeable sand layer 15 below the building's base slab 13, and its bottom and side walls are permeable. The sump 8 is located on the concrete pad 14 below the building's base slab 13, and its top is open. A sealing partition is provided between the top of the pressure relief pool 9 and the bottom of the sump 8. The pressure relief pipe 10 passes through the sealing partition, allowing communication between the pressure relief pool 9 and the sump 8. A pressure relief valve 11 is provided at the outlet end of the pressure relief pipe 10. The bottom of the pressure relief pipe 10 is located at the bottom of the pressure relief pool 9, and its top is located in the middle of the sump 8. This allows water at the bottom of the pressure relief pool 9 to be squeezed into the sump 8. The sump 8 contains a water level sensor 16 and a drain pipe 18. When the water level reaches a set limit, the control unit controls the drain pump 17 to start and pump the water into the municipal drainage pipe.

[0030] As an alternative, in this embodiment, the sidewall of the pressure relief pool 9 is constructed by piling up permeable bricks, so that the seepage water in the permeable sand layer 15 can be collected in the pressure relief pool 9. When the water pressure in the pressure relief pool 9 is greater than the set pressure of the pressure relief valve 11, the water in the pressure relief pool 9 can be discharged.

[0031] As an optional solution, in this embodiment, the pressure relief pool 9 is connected to at least one drainage channel 12. A gravel filter layer 20 and geotextile 19 are sequentially arranged above the drainage channel 12. The geotextile 19 is laid below the permeable sand layer 15. The pressure relief pool 9 can be located at or below the permeable sand layer 15. Drainage pipes or precast reinforced concrete trenches can be arranged within the drainage channel 12, as long as they have filtration and permeability functions. The drainage channel 12 preferably has a certain slope to facilitate the discharge of groundwater collected in the drainage channel 12 into the pressure relief pool 9. In this embodiment, the geotextile 19 effectively filters fine sand, silt, and clay particles in the soil, preventing them from entering the drainage pipe while allowing water to pass freely. Secondly, the gravel filter layer 20 (with a particle size typically of 10-20 mm) prevents silt from directly entering the drainage channel 12. The drainage channel 12 can collect moisture from the underground soil layer and discharge it into the pressure relief pool 9 through underground drainage pipes. It is worth noting that the tension piles should avoid drainage channels during construction to ensure the integrity of the tension piles. When positioning, the tension piles should maintain a certain distance (>300mm) from the drainage channels.

[0032] As an optional solution, in this embodiment, a water level sensor 16 and a drainage component are installed in the water collection well 8. Both the water level sensor 16 and the drainage component are connected to a controller. After the liquid level in the water collection well 8 reaches the set liquid level, the controller can control the drainage component to discharge the water in the water collection well 8 into the municipal drainage channel. The drainage component includes a drainage pump 17, a drainage pipe 18 and a drainage valve. The drainage pump 17 is installed in the water collection well 8 and is connected to the municipal drainage channel through the drainage pipe 18. A drainage valve is installed on the drainage pipe 18, and the pressure relief pressure can be selected according to the actual situation of the project.

[0033] In this embodiment, the entire pressure relief and drainage system is a whole consisting of a water collection well 8 and a pressure relief pool 9. The pressure relief pool 9 collects underground seepage water through the drainage channel 12. When the water in the pressure relief pool 9 accumulates to a certain pressure, the pressure relief valve 11 opens and discharges the water through the pressure relief pipe 10 to the water collection well 8. The water collection well 8 detects the water level change through the water level sensor 16. When the water level increases to a certain value, the drainage pump 17 is turned on to pump the water to the outside.

[0034] As an alternative, in this embodiment, a drainage channel can also be provided between the building base slab 13 and the concrete cushion layer 14, and the drainage channel is connected to the collection well 8. Drainage pipes are arranged in the drainage channel, and the concrete cushion layer 14 is poured on top. The filter pipes in the drainage channel collect water that does not flow into the underground drainage network and discharge it to the collection well 8.

[0035] The specific construction process of the combined anti-buoyancy drainage device in this embodiment includes the following steps: S1, During the construction of underground buildings, underground structural sidewalls are installed on the sides of the underground structural base slab. From bottom to top, the underground structural base slab is laid with a gravel filter layer 20, a geotextile 19, a permeable sand layer 15, and a concrete cushion layer 14. A drainage channel 12 is laid below the gravel filter layer 20. The drainage channel 12 can be a water filter pipe or a precast reinforced concrete trench. The geotextile and gravel filter layer are used to isolate fine soil particles to achieve water filtration and collection. Groundwater is collected into the pressure relief pool 9 through the drainage channel 12. The water filter pipe is equipped with a filter screen to prevent gravel from entering the pipe.

[0036] S2, the positioning and layout of the anti-tension piles, water collection well 8 and pressure relief pool 9 are carried out on the bottom slab of the underground structure. The water collection well 8 and pressure relief pool 9 are excavated by the sinking pipe excavation method. The pressure relief pool 9 is connected to the drainage channel 12 through the flow hole to ensure the effective drainage of the underground structure in the future. The anti-tension piles should avoid the drainage channel during construction. When positioning, the anti-tension piles should maintain a certain distance (usually >300mm) from the drainage channel to ensure the integrity of the anti-tension piles.

[0037] S3, a sealing baffle is installed on the pressure relief tank 9 to ensure the relative sealing of the pressure relief tank 9 so as to reach the set pressure relief value. A pressure relief pipe 10 is pre-embedded. The upper part of the pressure relief pipe 10 is located in the middle of the water collection well, and the lower end is located at the bottom of the pressure relief tank 9. A water passage hole is provided at the lower end of the pressure relief pipe 10. The groundwater pressure is monitored by the pressure gauge of the pressure relief filter pipe. When the pressure reaches a certain design threshold, the pressure relief valve 11 automatically opens to drain and relieve pressure. The water in the pressure relief tank 9 is discharged into the water collection well 8 through the pressure relief pipe 10.

[0038] S4, a water level sensor 16 is installed in the water collection well 8 to monitor the water level changes in the water collection well 8 in real time, and the terminal can remotely control the automatic adjustment of the working status of the drainage pump 17 according to the water level.

[0039] S5. Anti-tension piles are installed below the underground structure's base slab. Each anti-tension pile includes a pile body, anti-tension reinforcement, stirrups, and a grout-bonded structure. Pile locations are determined using surveying instruments. Holes are drilled using a long auger drill. Upon reaching the predetermined depth, grout is injected into the hole through the hollow tube of the auger rod and the nozzle of the drill bit while the drill is being lifted. The type of grout can be selected based on the actual engineering conditions. Several reinforcing bars are installed, passing through the underground structure's base slab and the underlying soil. The reinforcing bars are positioned within the anti-tension pile body, arranged in a cylindrical structure. The reinforcing bars are anchored to each other using stirrups installed above. Stirrups are densely arranged within 2m below the top of the anti-tension pile, with a spacing of 100mm-150mm. A steel structure bearing structure is installed within the anti-tension pile body to strengthen the connection with the anti-tension reinforcement. A 2-3mm thick polymer cement waterproof coating is applied to the outer side of the anti-tension pile body.

[0040] Example 2 like Figure 2 As shown, this embodiment provides a method for calculating the anti-buoyancy stability of the combined anti-buoyancy drainage device of Embodiment 1 above, which specifically includes the following steps: S1, Calculate the buoyancy force. The calculation of the buoyancy force on the building structure is as follows. Among them, F fk —The buoyancy force on the building structure, γ W —The density of water, A W —The cross-sectional area of ​​the building structure below the groundwater level. L – Length of the building structure; S2, the buoyancy resistance of a building structure mainly includes the structure's own weight, the self-weight of the pull-out piles, and their pull-out bearing capacity. The structure's own weight is calculated as follows. Among them, G K —The building structure's own weight, γ — The structural weight of the building. A – Cross-sectional area of ​​the building structure below the groundwater level. L – Length of the building structure The self-weight of the tension pile is calculated as follows: Among them, G P —The self-weight of the anti-uplift pile, γ — density of the tension pile V – Volume of the tension pile The bearing capacity of the tension pile is calculated as follows: Where, N K —Bearing capacity of tension piles T K —Standard value of ultimate tensile bearing capacity when the tensile pile fails as a whole. G P —The self-weight of the anti-uplift pile; S3. The anti-buoyancy stability of the building structure shall meet the following requirements. K – Stability coefficient of the building structure K w —The safety factor for the buoyancy resistance of the building structure (the value is determined according to the actual situation, usually 1.05-1.20); S4. Based on the self-weight of all structures above the pile foundation and the buoyancy resistance of the pile foundation, determine the buoyancy bearing capacity of the passive measures, and thereby define the pressure-limiting water level. Where h is the pressure-limiting water level. F – Anti-buoyancy force A – Area of ​​the foundation slab γ W —The density of water.

[0041] During use, when the groundwater level is lower than the pressure limit level, the pressure relief drainage component does not participate in the work until the pressure relief value is reached. The passive measures composed of the anti-uplift piles and the self-weight of the building structure resist the buoyancy below the actual water level. When the groundwater level is higher than the set pressure limit level, the drainage pump 17 starts under the control of the controller and uses the drainage pipe to discharge the groundwater into the municipal drainage channel. At the same time, the passive measures continue to resist the buoyancy below the pressure limit level, that is, the active and passive anti-buoyancy is combined.

[0042] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A combined anti-buoyancy drainage device, characterized in that: The structure includes an anti-tension pile assembly and a pressure relief drainage mechanism. At least one set of the anti-tension pile assembly and at least one pressure relief drainage mechanism are staggered on the building's base plate. The upper end of the anti-tension pile assembly is cast on the building's base plate, and the lower end is pre-embedded in the ground. The pressure relief drainage mechanism can relieve pressure on the seepage water below the building's base plate.

2. The combined anti-buoyancy drainage device according to claim 1, characterized in that: The anti-uplift pile assembly includes a horizontal stiffening plate and a vertical anchor pile. The horizontal stiffening plate and the vertical anchor pile are connected as a whole by casting. The center of the vertical anchor pile is connected to the center of the horizontal stiffening plate. The horizontal stiffening plate is cast in the building's base slab, and the vertical anchor pile is pre-embedded underground.

3. The combined anti-buoyancy drainage device according to claim 2, characterized in that: The horizontal stiffening plate includes several horizontal bars and stirrups arranged in the horizontal direction. The stirrups are tied to the horizontal bars at equal intervals. The horizontal stiffening plate is a cast-in-place reinforced concrete component.

4. The combined anti-buoyancy drainage device according to claim 2, characterized in that: The vertical anchor pile includes several longitudinal bars and stirrups arranged in the vertical direction. The stirrups are tied to the longitudinal bars at equal intervals. The vertical anchor pile is a cast-in-place reinforced concrete component.

5. The combined anti-buoyancy drainage device according to claim 2, characterized in that: The surface of the vertical anchor pile is coated with a waterproof coating; at least one anchor bar is installed through the center of the horizontal stiffening plate and the vertical anchor pile.

6. The combined anti-buoyancy drainage device according to claim 1, characterized in that: The pressure relief and drainage mechanism includes a water collection well, a pressure relief pool, a pressure relief pipe, and a pressure relief valve. The pressure relief pool is located in a permeable sand layer below the building's foundation slab and its bottom and side walls are permeable. The water collection well is located on a concrete pad below the building's foundation slab and its top is open. A sealing partition is provided between the top of the pressure relief pool and the bottom of the water collection well. The pressure relief pipe passes through the sealing partition to connect the pressure relief pool and the water collection well. The pressure relief valve is provided at the outlet end of the pressure relief pipe.

7. The combined anti-buoyancy drainage device according to claim 6, characterized in that: The sidewalls of the pressure relief pool are constructed of permeable bricks, allowing seepage water from the permeable sand layer to collect within the pool.

8. The combined anti-buoyancy drainage device according to claim 7, characterized in that: The water collection well is equipped with a water level sensor and a drainage assembly. Both the water level sensor and the drainage assembly are communicatively connected to a controller. When the water level in the water collection well reaches a set level, the controller can control the drainage assembly to discharge the water in the water collection well into the municipal drainage channel. The drainage assembly includes a drainage pump, a drainage pipe, and a drainage valve. The drainage pump is installed in the water collection well and is connected to the municipal drainage channel through the drainage pipe. The drainage pipe is equipped with a drainage valve.

9. The combined anti-buoyancy drainage device according to claim 7, characterized in that: The pressure relief pool is connected to at least one drainage channel, and a gravel filter layer and a geotextile are sequentially arranged above the drainage channel, with the geotextile laid below the permeable sand layer.

10. A method for calculating the anti-buoyancy stability of the combined anti-buoyancy drainage device according to any one of claims 1-9, characterized in that, Specifically, the steps include the following: S1, Calculate the buoyancy force. The calculation of the buoyancy force on the building structure is as follows. Among them, F fk —The buoyancy force on the building structure, γ W —The density of water, A W —The cross-sectional area of ​​the building structure below the groundwater level. L—Length of the building structure; S2, the buoyancy resistance of a building structure mainly includes the structure's own weight, the self-weight of the pull-out piles, and the pull-out bearing capacity; The structure's own weight is calculated as follows. Among them, G K —The building structure's own weight, γ — The structural weight of the building. A – Cross-sectional area of ​​the building structure below the groundwater level. L—Length of the building structure; The self-weight of the tension pile is calculated as follows: Among them, G P —The self-weight of the anti-uplift pile, γ — density of the tension pile V – Volume of the tension pile The bearing capacity of the tension pile is calculated as follows: Where, N K —Bearing capacity of tension piles T K —Standard value of ultimate tensile bearing capacity when the tensile pile fails as a whole. G P —The self-weight of the anti-uplift pile; S3. The anti-buoyancy stability of the building structure shall meet the following requirements. K – Stability coefficient of the building structure K w —The buoyancy safety factor of the building structure (the value is determined according to the actual situation, usually 1.05-1.20); S4. Based on the self-weight of all structures above the pile foundation and the buoyancy resistance of the pile foundation, determine the buoyancy bearing capacity of the passive measures, and thereby define the pressure-limiting water level. Where h represents the pressure-limiting water level. F – Anti-buoyancy force A – Area of ​​the foundation slab γ W —The density of water.

Images