Subway station active and passive anti-floating structure and construction method thereof

Abstract

The application is suitable for the technical field of underground engineering anti-floating, and provides a subway station active and passive anti-floating structure and a construction method thereof, wherein the subway station active and passive anti-floating structure comprises: a multi-field sensing network comprising a plurality of sensors arranged in an underground water collection and drainage structure layer, a station structure and a surrounding stratum, and used for collecting water level, settlement and rainfall parameters in real time; a hierarchical decision hub electrically connected with the multi-field sensing network and an intelligent mechanical execution unit respectively, and used for calculating an optimal pressure limiting water level based on a dynamic pressure limiting model, and controlling the intelligent mechanical execution unit to perform corresponding actions. The subway station active and passive anti-floating structure provided by the application forms an intelligent and self-adapting anti-floating system through the cooperative work of the underground water collection and drainage structure layer, the intelligent mechanical execution unit, the multi-field sensing network and the hierarchical decision hub.

Description

Technical Field

[0001] This invention belongs to the field of anti-buoyancy technology in underground engineering, and particularly relates to an active and passive anti-buoyancy structure for subway stations. Background Technology

[0002] With the deepening development of urban underground space, subway station construction faces increasingly complex hydrogeological conditions. In areas with high groundwater levels, station structures are subjected to the buoyancy of groundwater for extended periods, making anti-buoyancy stability a key issue in engineering design.

[0003] Traditional anti-buoyancy measures for subway stations are divided into two categories: passive and active anti-buoyancy measures. Passive anti-buoyancy measures mainly balance buoyancy by increasing the structure's self-weight, installing anti-buoyancy piles, or anti-buoyancy anchors. However, the construction of anti-buoyancy piles requires a large amount of concrete and steel reinforcement, significantly increasing the project cost; at the same time, the drilling process causes significant disturbance to the strata, which may lead to settlement of surrounding buildings, and the construction period is long, making it difficult to meet the needs of rapid construction.

[0004] Active anti-buoyancy systems dynamically lower the groundwater level through drainage systems to reduce buoyancy, offering advantages such as cost-effectiveness and adaptability. However, traditional drainage systems often employ fixed threshold control strategies, failing to dynamically adjust based on real-time hydrological changes and structural responses. For instance, during heavy rainfall, the groundwater level rises rapidly, and fixed threshold systems react sluggishly, easily leading to water level exceeding limits. Furthermore, when the risk of structural settlement is high, the system continues to drain water in a fixed manner, potentially exacerbating ground subsidence and deformation.

[0005] In recent years, some researchers have attempted to combine automated monitoring with drainage systems to develop sensor-based anti-buoyancy systems. However, existing systems still suffer from significant technical bottlenecks: First, sensor networks typically monitor only a single parameter, such as water level, lacking the ability to comprehensively perceive and fuse data from multiple fields, including groundwater level, structural settlement, and rainfall intensity; second, control strategies are too simplistic, making it difficult to achieve a dynamic balance between anti-buoyancy safety and settlement control; and finally, the system lacks a mechanical actuator capable of actively adjusting the pressure-limiting water level, hindering real-time adjustment and preventing true "active-passive coordinated anti-buoyancy." These shortcomings make it difficult for existing technologies to ensure the long-term safety and stability of subway stations under complex hydrogeological conditions, necessitating urgent improvement. Summary of the Invention

[0006] The purpose of this invention is to provide an active and passive anti-buoyancy structure for subway stations, aiming to solve the above-mentioned problems.

[0007] This invention is implemented as follows: a subway station active and passive anti-buoyancy structure, comprising:

[0008] The underground drainage and collection structure layer is located below the station structure floor slab and is used to collect groundwater and form zoned water collection units.

[0009] The intelligent mechanical execution unit is installed in a reserved cavity in the bottom plate of the station structure and is connected to the underground drainage structure layer for dynamically regulating the groundwater level.

[0010] A multi-field sensing network, including multiple sensors deployed in the underground drainage structure layer, station structure and surrounding strata, is used to collect water level, settlement and rainfall parameters in real time;

[0011] The hierarchical decision-making center is electrically connected to the multi-field sensing network and the intelligent mechanical execution unit, respectively. It calculates the optimal pressure limit water level based on the dynamic pressure limit model and controls the intelligent mechanical execution unit to perform corresponding actions.

[0012] A further technical solution is to set up a transverse partition wall at equal intervals along the longitudinal direction of the station to divide the space under the station's structural slab into several independent water collection compartments.

[0013] The transverse partition wall is made of plain concrete, and the top of the water collection compartment is covered with a waterproof isolation layer, extending from the surface of the foundation soil to the bottom of the waterproof isolation layer.

[0014] A further technical solution is that the interior of each water collection compartment is provided with, from bottom to top, the following:

[0015] The filter protective layer is laid on the surface of the foundation soil and is composed of geotextile and medium-coarse sand;

[0016] The main drainage layer is laid on top of the reverse filter protective layer and adopts a three-dimensional composite drainage network;

[0017] The secondary drainage layer is laid on top of the main drainage layer. It uses graded crushed stone and has flexible permeable pipes buried inside it.

[0018] The flexible permeable pipe is arranged longitudinally along the station, with its lower end facing the preset water collection point at the lowest point of the bottom surface of the water collection compartment, and its upper end connected to the reserved cavity.

[0019] A base slab protective layer is poured on top of the waterproof isolation layer, and the station structure base slab is poured on top of the base slab protective layer.

[0020] A further technical solution involves installing a set of intelligent mechanical actuators for each water collection compartment. These actuators are installed within a pre-reserved cavity in the station's structural floor slab, and the top of the cavity is equipped with an openable maintenance cover. The intelligent mechanical actuator includes:

[0021] The liftable water storage tank is installed in a pre-reserved cavity and is partially submerged in the water in the water collection compartment.

[0022] An electric lift is installed at the top of a pre-reserved cavity. Its output shaft is fixedly connected to a threaded shaft that passes through the connecting seat of the lifting water tank and is threadedly connected. The connecting seat of the lifting water tank is vertically slidably connected to the pre-reserved cavity.

[0023] A flexible water inlet pipe connects the bottom of the liftable water storage tank to a reserved cavity, and a stainless steel filter screen is installed at the water inlet.

[0024] The overflow outlet is located on the side wall of the lifting water tank and is connected to the variable frequency drainage pump group of the external station through a flexible drainage hose. It is used to discharge water entering through the overflow outlet from the station.

[0025] The elevation of the overflow outlet changes as the lifting water tank rises and falls, forming a dynamic pressure-limiting water level.

[0026] A complete drainage path is formed by water collection compartments, reserved cavities, liftable water storage tanks, overflow outlets, and variable frequency drainage pump sets.

[0027] A further technical solution is that the multi-field sensing network includes:

[0028] Water level gauges are installed in each water collection compartment and in observation wells outside the foundation pit to collect real-time water level data. ;

[0029] A hydrostatic level is installed on the station structure floor and surrounding ground surface to collect settlement data S(t);

[0030] A rain gauge, installed on the ground at the entrance of the station ventilation shaft, is used to collect rainfall intensity R(t);

[0031] An electromagnetic flow meter is installed on the outlet pipe of a variable frequency drainage pump unit to collect drainage flow rate Q(t).

[0032] All sensors are electrically connected to the hierarchical decision-making center via a data acquisition module.

[0033] A further technical solution is that the hierarchical decision-making center has a built-in dynamic pressure limiting model, which is used to calculate the optimal pressure limiting water level based on real-time monitoring data and generate control commands;

[0034] The objective function of the dynamic pressure limiting model is:

[0035] ;

[0036] The constraints are: , , ;

[0037] in To limit the water level, To actively resist buoyancy and start-up probability, To predict settlement, To regulate the allowable cumulative settlement, This is the water level influence coefficient. This is the settlement influence coefficient. , For the permissible active anti-buoyancy start probability, The cumulative settlement allowed by the engineering design. For drainage capacity, This refers to groundwater seepage flow. Indicates taking the objective function The independent variable corresponding to the minimum value The value, This is the optimal pressure-limiting water level.

[0038] A further technical solution is that the active anti-buoyancy activation probability is determined based on the time-varying statistical characteristics of the groundwater level, and its calculation method is as follows:

[0039] ;

[0040] in For real-time groundwater levels, To limit the water level, For integration variables, Represents possible groundwater level values. This is the average groundwater level. This represents the standard deviation of the groundwater level.

[0041] A further technical solution is that the hierarchical decision-making center executes the following hierarchical control strategy based on the calculation results of the dynamic pressure limiting model and real-time monitoring data:

[0042] Normal regulation: when and At that time, the variable frequency drainage pump set is controlled to operate at the set water level. The current pressure limit water level (i.e., the level obtained in the previous optimization) );

[0043] Heavy rain warning and control: When the rain gauge detects that the rainfall intensity R(t) exceeds the heavy rain warning threshold, the electric lift is controlled to drive the lifting water tank to descend, reduce the overflow outlet elevation, and drain water in advance to free up storage capacity;

[0044] Settlement priority control: When the hydrostatic level detects settlement At the same time, the electric lift is controlled to drive the lifting water tank to rise, raising the overflow outlet elevation and reducing the drainage volume to control the development of settlement;

[0045] During emergency control, when the water level reaches the structural anti-buoyancy limit level, the following action will be taken: control the variable frequency drainage pump set to drain water at full capacity.

[0046] A construction method for an active and passive anti-buoyancy structure for a subway station, applied to the aforementioned active and passive anti-buoyancy structure for a subway station, includes the following steps:

[0047] The first step is to excavate the foundation pit to the design elevation, level the foundation soil, and construct a horizontal partition wall to divide the area below the base slab into several water collection compartments.

[0048] The second step involves laying a reverse filter protective layer, a main drainage layer, a secondary drainage layer, and a flexible permeable pipe in sequence within the water collection compartment to form an underground water collection and drainage structure layer.

[0049] The third step is to pour the waterproof isolation layer, the bottom slab protective layer and the station structure bottom slab, and reserve installation space at the station structure bottom slab location;

[0050] The fourth step is to install the intelligent mechanical actuator in the reserved cavity and connect it to the water collection compartment;

[0051] The fifth step is to deploy various sensors in the multi-field sensing network, install the hierarchical decision-making center, and complete system debugging.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] The present invention provides a passive and active anti-buoyancy structure for subway stations. Through the collaborative work of an underground drainage structure layer, an intelligent mechanical execution unit, a multi-field sensing network, and a hierarchical decision-making center, an intelligent and adaptive anti-buoyancy system is formed. This effectively solves the technical problems of lack of multi-field information fusion, single drainage control strategy, and inability to actively adjust the pressure limit water level in the prior art, and significantly improves the intelligence level and operational reliability of the anti-buoyancy structure of subway stations.

[0054] This invention provides a passive and active anti-buoyancy structure for subway stations. Upon receiving instructions, the electric elevator in the intelligent mechanical execution unit dynamically adjusts the elevation of the overflow outlet. In this way, the groundwater level in the underground drainage structure layer is precisely controlled below the dynamically adjusted pressure limit level, effectively balancing the buoyancy of groundwater on the station's structural base while simultaneously controlling the settlement of surrounding strata. This closed-loop control mechanism, based on real-time data and an optimization model, enables the entire anti-buoyancy system to adaptively adjust according to environmental changes and structural responses, significantly improving the precision and intelligence of the anti-buoyancy strategy and solving the problem that traditional fixed threshold control strategies cannot dynamically balance anti-buoyancy safety and settlement control.

[0055] This invention provides a passive and active anti-buoyancy structure for subway stations. Through a refined layered drainage structure and isolation design, combined with transverse partition walls, the space beneath the station's foundation slab is divided into several independent water collection compartments. This solution not only solves the problem of insufficient drainage efficiency that may exist with a single drainage layer, but also effectively protects the foundation soil through a reverse filter protective layer, avoiding the risk of foundation settlement that may occur with traditional drainage systems. Simultaneously, the waterproof isolation layer and the foundation slab protective layer ensure the long-term stability and durability of the station's foundation slab, effectively improving the reliability of the entire subway station's passive and active anti-buoyancy structure. Attached Figure Description

[0056] Figure 1 A schematic diagram of the active and passive anti-buoyancy structure of a subway station;

[0057] Figure 2 A schematic diagram of the structure in the reserved cavity;

[0058] Figure 3 A structural diagram showing the composition of the active and passive anti-buoyancy structures of a subway station;

[0059] Figure 4 A schematic diagram illustrating the construction steps of the active and passive anti-buoyancy structure for a subway station.

[0060] In the attached diagram: 1. Station structural base slab; 2. Reserved cavity; 3. Transverse partition wall; 4. Water collection compartment; 5. Foundation soil; 6. Inspection cover plate; 7. Filter protection layer; 8. Main drainage layer; 9. Secondary drainage layer; 10. Flexible permeable pipe; 11. Waterproof isolation layer; 12. Base slab protective layer; 13. Lifting water storage tank; 14. Electric elevator; 15. Flexible inlet pipe; 16. Overflow outlet; 17. Flexible drainage hose. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0062] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0063] like Figure 1-2 As shown, an embodiment of the present invention provides a subway station active and passive anti-buoyancy structure, comprising:

[0064] The underground drainage structure layer is located below the station structure slab 1 and is used to collect groundwater and form zoned water collection units. Its main function is to effectively manage the groundwater below the station structure. Through zoned design, it can carry out differentiated treatment for the hydrological conditions of different areas, thereby improving drainage efficiency and anti-buoyancy stability.

[0065] The intelligent mechanical execution unit is installed in the reserved cavity 2 of the station structure bottom plate 1 and is connected to the underground drainage structure layer. It is used to dynamically regulate the groundwater level. The core function of this unit is to dynamically adjust the groundwater level according to the control command, so as to realize the active control of buoyancy and adapt to the constantly changing hydrological environment and structural response.

[0066] The multi-field sensing network includes multiple sensors deployed in the underground drainage structure layer, station structure and surrounding strata to collect water level, settlement and rainfall parameters in real time. This network is responsible for collecting various environmental and structural parameters, including water level, settlement and rainfall, in real time, to provide comprehensive and accurate data support for subsequent intelligent decision-making.

[0067] The hierarchical decision-making center is electrically connected to the multi-field sensing network and the intelligent mechanical execution unit, respectively. It calculates the optimal pressure limit water level based on the dynamic pressure limit model and controls the intelligent mechanical execution unit to perform corresponding actions. Based on the built-in dynamic pressure limit model, the hierarchical decision-making center analyzes and processes the collected multi-field data, calculates the optimal pressure limit water level, and sends control commands to the intelligent mechanical execution unit to achieve a dynamic balance between anti-buoyancy safety and settlement control.

[0068] The dynamic pressure limiting model is a mathematical model used within the hierarchical decision-making center to calculate the optimal pressure limiting water level. This model comprehensively considers multiple factors such as water level, settlement, and rainfall, and uses an optimization algorithm to determine a dynamic upper limit of water level that ensures structural buoyancy safety while also taking settlement control into account.

[0069] This embodiment introduces a multi-field sensing network to achieve comprehensive perception and fusion of multi-source information such as water level, settlement, and rainfall, overcoming the limitations of traditional systems that rely on single information acquisition methods. For example, in the above example, the hierarchical decision-making center not only considers water level but also combines rainfall forecasts and structural settlement data for decision-making, making the anti-buoyancy strategy more comprehensive and accurate. Furthermore, this embodiment achieves dynamic regulation of the groundwater level through an intelligent mechanical execution unit, enabling proactive adjustment based on the optimal pressure-limiting water level calculated by the hierarchical decision-making center, rather than relying solely on a preset fixed water level. This dynamic adjustment capability allows the system to flexibly respond to complex and changing hydrogeological conditions, such as lowering the water level in advance before heavy rain or reducing drainage when the risk of structural settlement increases, thereby achieving a dynamic balance between anti-buoyancy safety and settlement control. Traditional systems often struggle to meet both of these needs, potentially leading to excessive drainage causing settlement or insufficient drainage causing buoyancy.

[0070] like Figure 1 As shown, in a preferred embodiment of the present invention, a transverse partition wall 3 is set at equal intervals along the longitudinal direction of the station to divide the space below the station structure floor 1 into several independent water collection compartments 4.

[0071] The transverse partition wall 3 is made of plain concrete, and the top of the water collection compartment 4 is covered with a waterproof isolation layer 11, which extends from the surface of the foundation soil 5 to the bottom of the waterproof isolation layer 11.

[0072] In this embodiment, by setting transverse partition walls 3 at equal intervals along the longitudinal direction of the station below the station structure base slab 1, the entire underground drainage structure layer space is divided into several independent water collection compartments 4. These transverse partition walls 3 are made of plain concrete and extend from the surface of the foundation soil 5 to the bottom surface of the waterproof isolation layer 11, thus forming a continuous and dense groundwater barrier. This structural design makes each water collection compartment 4 an independent hydraulic unit, effectively preventing the free flow of groundwater in the longitudinal direction of the station and the mutual influence of water pressure. In the above-mentioned active and passive anti-buoyancy structure of the subway station, the underground drainage structure layer was originally used to collect groundwater and form zoned water collection units. However, by introducing transverse partition walls 3, the concept of "zoned water collection units" is precisely realized. Each water collection compartment 4 can independently collect groundwater within its range and connect with intelligent mechanical execution units, thereby realizing independent monitoring and dynamic control of the water level in each compartment. This refined zoning management avoids the problem of uneven water level control caused by cross-flow in traditional drainage systems, providing a reliable foundation for the precise control of subsequent intelligent mechanical execution units, thereby improving the response accuracy and control effect of the entire anti-buoyancy structure to groundwater buoyancy.

[0073] like Figure 1 As shown, in a preferred embodiment of the present invention, each of the water collection compartments 4 is provided with the following components arranged from bottom to top:

[0074] The filter protective layer 7 is laid on the surface of the foundation soil 5 and is composed of geotextile and medium-coarse sand.

[0075] The main drainage layer 8 is laid on top of the reverse filter protective layer 7 and adopts a three-dimensional composite drainage network.

[0076] Secondary drainage layer 9 is laid on top of main drainage layer 8, using graded crushed stone and with flexible permeable pipes 10 buried inside it;

[0077] The flexible permeable pipe 10 is arranged longitudinally along the station, and its lower end faces the preset water collection point at the lowest point of the bottom surface of the water collection compartment 4. The upper end of the flexible permeable pipe 10 is connected to the reserved cavity 2.

[0078] A base slab protective layer 12 is poured on top of the waterproof isolation layer 11, and the station structure base slab 1 is poured on top of the base slab protective layer 12.

[0079] In this embodiment, by optimizing the internal structure of the water collection compartment 4, the synergistic effects of efficient drainage, foundation protection, and structural isolation are achieved.

[0080] Specifically, groundwater first permeates the foundation soil 5 and encounters the filter layer 7 laid on its surface. The filter layer 7, composed of geotextile and medium-coarse sand, has a fine pore structure that effectively prevents fine particles of the foundation soil 5 from being washed away with the water, thus protecting the stability of the foundation soil 5 while allowing groundwater to infiltrate smoothly. The infiltrated groundwater then enters the main drainage layer 8 laid on top of the filter layer 7. The main drainage layer 8 employs a three-dimensional composite drainage network, forming numerous interconnected drainage channels within it. This allows for the rapid collection and lateral conduction of large amounts of groundwater, significantly improving drainage efficiency.

[0081] Subsequently, the water flows further into the secondary drainage layer 9, which is laid on top of the main drainage layer 8. The secondary drainage layer 9 is composed of graded crushed stone, and its high porosity further accelerates the water collection. More importantly, the flexible permeable pipes 10 embedded within the secondary drainage layer 9 are arranged longitudinally along the station, with their lower ends precisely facing the pre-set water collection point at the lowest point of the water collection compartment 4, ensuring efficient and directional water collection. The upper ends of the flexible permeable pipes 10 connect to the reserved cavity 2, directing the collected water into the space where the intelligent mechanical execution unit is located. This layered, graded, and directional drainage path design greatly improves the efficiency of groundwater collection and discharge, preventing localized water accumulation.

[0082] Based on this, the top of the water collection compartment 4 is covered with a waterproof isolation layer 11, which effectively prevents groundwater from seeping upwards to the main structure of the station. A base slab protective layer 12 is poured on top of the waterproof isolation layer 11, providing a solid and flat support for the station structure base slab 1 above, and also protecting the waterproof isolation layer 11. Finally, the station structure base slab 1 is poured on top of the base slab protective layer 12, forming a complete anti-buoyancy structure.

[0083] like Figure 2 As shown, in a preferred embodiment of the present invention, each water collection compartment 4 is provided with a set of intelligent mechanical execution units. The intelligent mechanical execution units are installed in the reserved cavity 2 of the station structure base plate 1, and the top of the reserved cavity 2 is provided with an openable maintenance cover 6. The intelligent mechanical execution unit includes:

[0084] The liftable water storage tank 13 is set in the reserved cavity 2 and is partially submerged in the water in the water collection compartment 4.

[0085] An electric lift 14 is installed on the top of the reserved cavity 2. Its output shaft is fixedly connected to a threaded shaft that passes through the connecting seat of the lifting water tank 13 and is threadedly connected. The connecting seat of the lifting water tank 13 is vertically slidably connected to the reserved cavity 2.

[0086] A flexible water inlet pipe 15 connects the bottom of the liftable water storage tank 13 to the reserved cavity 2, and a stainless steel filter screen is installed at the water inlet.

[0087] Overflow outlet 16 is located on the side wall of the lifting water tank 13 and is connected to the variable frequency drainage pump group of the external station through a flexible drainage hose 17. It is used to discharge water entering through overflow outlet 16 out of the station.

[0088] The elevation of the overflow outlet 16 changes with the rise and fall of the lifting water tank 13, forming a dynamic pressure limiting water level;

[0089] A complete drainage path is formed by the water collection compartment 4, the reserved cavity 2, the lifting water storage tank 13, the overflow port 16, and the variable frequency drainage pump set.

[0090] In this embodiment, the groundwater collected in the aforementioned water collection chamber 4 is introduced into a reserved cavity 2 below the station structure floor 1 via a flexible permeable pipe 10. An intelligent mechanical execution unit is installed within the reserved cavity 2, with its core component, a lifting water storage tank 13, partially submerged in the introduced water. An electric lift 14 precisely controls the vertical position of the lifting water storage tank 13 via a threaded shaft, thereby dynamically adjusting the elevation of the overflow port 16 located on the side wall of the water storage tank. When the water level (i.e., the groundwater level) in the reserved cavity 2 exceeds the current elevation of the overflow port 16, the water is discharged through the overflow port 16 and the flexible drainage hose 17, and then pumped out by the variable frequency drainage pump set of the external station. This design allows the elevation of the overflow port 16 to be adjusted in real time according to the instructions of the hierarchical decision-making center, thus forming a dynamic pressure-limiting water level. The entire system, from the water collection chamber 4 to the variable frequency drainage pump set, constitutes a complete and dynamically adjustable drainage path. This scheme, combined with the aforementioned active and passive anti-buoyancy structures of the subway station, particularly its synergistic effect with the zoned water collection unit (water collection compartment 4) and the hierarchical decision-making center, enables the hierarchical decision-making center to calculate the optimal pressure-limiting water level based on real-time data collected by the multi-field sensing network. It then directly drives the lifting water tank 13 via the electric lift 14 to physically change the elevation of the overflow outlet 16, achieving precise and proactive control of the groundwater level. This overcomes the limitations of traditional fixed-threshold drainage systems in adapting to complex hydrogeological conditions and structural responses, achieving a dynamic balance between anti-buoyancy safety and settlement control.

[0091] Overflow port 16 is an opening on the side wall of the lift-type water tank 13, used to automatically discharge excess water when the water level reaches a specific height. Flexible drainage hose 17 is a flexible pipe connecting overflow port 16 to an external drainage pump unit. The variable frequency drainage pump unit is a pumping station capable of adjusting the drainage volume according to demand. Its function is that overflow port 16 directly reflects the dynamic pressure-limiting water level; when the water level in the lift-type water tank 13 exceeds the elevation of overflow port 16, water is discharged through overflow port 16. Flexible drainage hose 17 ensures the continuity of the drainage path when the water tank is raised and lowered. The variable frequency drainage pump unit is responsible for efficiently and energy-savingly transporting the discharged water to the outside of the station.

[0092] The variable frequency drainage pump set can consist of multiple variable frequency pumps connected in parallel to meet different drainage volume requirements and improve system redundancy. The elevation of the overflow outlet 16 changes with the rise and fall of the lifting water tank 13, forming a dynamic pressure-limiting water level. This is one of the core innovations of this scheme. By changing the physical height of the overflow outlet 16, the control target of groundwater is directly changed, thereby achieving precise, dynamic, and active regulation of the groundwater level to adapt to different hydrogeological conditions and structural response requirements. The electric lift 14 receives instructions from the hierarchical decision-making center and precisely controls the vertical position of the lifting water tank 13, so that the elevation of the overflow outlet 16 is continuously adjustable within a preset range. The water collection compartment 4, the reserved cavity 2, the lifting water tank 13, the overflow outlet 16, and the variable frequency drainage pump set form a complete drainage path, ensuring that groundwater can be discharged smoothly and efficiently from below the station structure floor slab 1, which is the basis for achieving the anti-buoyancy function. The various components in the drainage path are tightly connected by pipes, connectors and seals to form a closed or semi-closed system to prevent water leakage or debris from entering.

[0093] In a preferred embodiment of the present invention, the multi-field sensing network includes:

[0094] Water level gauges are installed in each water collection compartment 4 and in the observation well outside the foundation pit to collect real-time water level data. ;

[0095] A static level is installed on the station structure base slab 1 and the surrounding ground surface to collect settlement data S(t);

[0096] A rain gauge, installed on the ground at the entrance of the station ventilation shaft, is used to collect rainfall intensity R(t);

[0097] An electromagnetic flow meter is installed on the outlet pipe of a variable frequency drainage pump unit to collect drainage flow rate Q(t).

[0098] All sensors are electrically connected to the hierarchical decision-making center via a data acquisition module.

[0099] In this embodiment, a comprehensive multi-field sensing network is constructed, which effectively solves the problem that when intelligent mechanical actuators dynamically regulate groundwater levels, the lack of real-time comprehensive sensing of water level, settlement, rainfall and drainage flow leads to inaccurate control strategies and the inability to achieve a dynamic balance between anti-buoyancy safety and settlement control.

[0100] Specifically, the coordinated deployment of water level gauges, hydrostatic levels, rain gauges, and electromagnetic flowmeters enables the hierarchical decision-making center to acquire real-time, high-precision data on groundwater levels, structural settlement, external rainfall, and drainage flow. This data provides comprehensive and accurate input to the dynamic pressure-limiting model built into the hierarchical decision-making center, allowing the model to comprehensively consider the dual objectives of anti-buoyancy safety and settlement control, and calculate the optimal pressure-limiting water level.

[0101] Based on this, the hierarchical decision-making center can perform refined and predictive control of intelligent mechanical execution units and variable frequency drainage pump sets according to real-time monitoring data and model calculation results. For example, when heavy rainfall is predicted, the system can lower the pressure limit water level in advance for pre-drainage; when abnormal settlement is detected, the strategy can be adjusted to reduce the drainage volume, thereby effectively controlling the development of settlement. This dynamic regulation capability based on multi-field perception significantly improves the intelligence level and adaptability of the active and passive anti-buoyancy structures of subway stations, ensuring the long-term stability and safety of station structures under complex hydrogeological conditions, while optimizing drainage energy consumption and achieving a dynamic balance between anti-buoyancy safety and settlement control.

[0102] In a preferred embodiment of the present invention, the hierarchical decision-making center has a built-in dynamic pressure limiting model, which is used to calculate the optimal pressure limiting water level based on real-time monitoring data and generate control commands.

[0103] The objective function of the dynamic pressure limiting model is:

[0104] ;

[0105] The constraints are: , , ;

[0106] in To limit the water level, This refers to the probability of active anti-buoyancy activation, i.e., the probability that the water level exceeds the pressure limit. To predict settlement, To regulate the allowable cumulative settlement, This is the water level influence coefficient. This is the settlement influence coefficient. , For the permissible active anti-buoyancy start probability, The cumulative settlement allowed by the engineering design. For drainage capacity, This refers to groundwater seepage flow. Indicates taking the objective function The independent variable corresponding to the minimum value The value, This is the optimal pressure-limiting water level.

[0107] In this embodiment, the dynamic pressure limiting model built into the hierarchical decision-making center is the core component for achieving intelligent regulation. It can be a software module or algorithm program integrated within the hierarchical decision-making center. This model aims to continuously evaluate multi-source monitoring data and calculate an optimal groundwater pressure limiting level that balances anti-buoyancy safety and settlement control.

[0108] Calculating the optimal pressure limit water level based on real-time monitoring data refers to the process by which the hierarchical decision-making center uses real-time data collected by a multi-field sensing network (such as water level gauges, hydrostatic levels, rain gauges, electromagnetic flowmeters, etc.) as input, processes and analyzes the data through a dynamic pressure limit model, and thus obtains the optimal pressure limit water level value under the current operating conditions. This calculation process can be an iterative solution process, or it can directly output the result based on preset rules or models.

[0109] The generation of control commands refers to the process by which the hierarchical decision-making center converts the calculated optimal pressure limit water level into executable commands and sends them to the intelligent mechanical execution unit. These commands can be electrical signals, digital communication protocols, or pneumatic / hydraulic signals, used to drive the electric lift 14 to adjust the position of the lifting water storage tank 13, thereby changing the elevation of the overflow port 16.

[0110] The objective function of the dynamic pressure-limiting model is a mathematical expression used to quantify the combined risks or costs associated with the probability of initiating active anti-buoyancy measures and the predicted settlement at a specific pressure-limiting water level. By minimizing this function, the system can find the optimal balance between anti-buoyancy safety and settlement control.

[0111] Among them, the weighting coefficient and The system can be flexibly adjusted according to actual engineering needs, geological conditions, or safety priorities. The constraints are a series of inequalities that define the boundaries for the safe operation of the system. These constraints ensure that the calculated optimal pressure limit water level does not lead to unacceptable risks (such as excessively high active anti-buoyancy activation probability or excessive settlement) nor exceed the system's physical drainage capacity. and The value can be dynamically adjusted according to the importance of the project, hydrogeological conditions, or structural response sensitivity, or it can be calibrated through the analytic hierarchy process or expert experience.

[0112] The pressure-limiting water level represents the target groundwater level control value to be set by the hierarchical decision-making center. This value is iteratively optimized in the system's preset optimization model, and the optimization result... As the final instruction, it is input to the intelligent mechanical execution unit.

[0113] The predicted settlement is expressed at a given pressure limit water level. Below, the predicted cumulative settlement value of the station structure and surrounding strata is calculated. This value can be estimated using empirical formulas, numerical simulations, or regression models based on historical data, reflecting the potential impact of drainage behavior on strata settlement. The allowable cumulative settlement is usually set according to relevant standards or structural safety requirements and is used to normalize the settlement index.

[0114] The allowable active anti-buoyancy initiation probability is a fixed input parameter determined based on the structural anti-buoyancy safety level and design specifications. The cumulative settlement allowed by the engineering design is the upper limit of settlement control determined during the engineering design phase. The drainage capacity is determined by the performance curve of the variable frequency drainage pump set and the number of operating units, and can be pre-calibrated and stored in the hierarchical decision-making center. The groundwater seepage flow rate is calculated based on hydrogeological parameters (permeability coefficient, hydraulic gradient, etc.) and real-time water level difference, using Darcy's law or numerical seepage models. It can also be inverted and corrected by combining measured data from electromagnetic flowmeters.

[0115] Quantified at a specific pressure limit water level The weighted average cost of the system's "anti-buoyancy start-up risk" and "structural settlement risk" is as follows. Operators indicate the objective function. The value corresponding to the minimum value This value represents the optimal pressure limiting water level under the current operating conditions. .

[0116] The hierarchical decision-making center will As a control command, the intelligent mechanical execution unit is sent to adjust the elevation of the overflow port (16) of the lifting water tank (13) to achieve dynamic and precise control of the groundwater level. This effectively controls ground subsidence while ensuring anti-buoyancy safety, and realizes refined control of active and passive coordinated anti-buoyancy.

[0117] The proposed solution utilizes a dynamic pressure-limiting model built into a hierarchical decision-making center to achieve intelligent and dynamic control of the active and passive anti-buoyancy structures of subway stations. Specifically, the hierarchical decision-making center continuously receives real-time monitoring data from a multi-field sensing network (including water level gauges, hydrostatic levels, rain gauges, electromagnetic flowmeters, etc.). This data serves as input to the dynamic pressure-limiting model, which uses its built-in optimization algorithm with the active anti-buoyancy initiation probability and predicted settlement as objective functions, combined with preset constraints (such as the allowable active anti-buoyancy initiation probability, the cumulative settlement allowed by regulations, and the relationship between drainage capacity and groundwater seepage flow), to calculate the optimal pressure-limiting water level under the current operating conditions. This calculation process aims to minimize overall risk while ensuring the system operates within a safe range. Once the optimal pressure-limiting water level is determined, the hierarchical decision-making center generates corresponding control commands and sends them to the intelligent mechanical execution unit.

[0118] Upon receiving a command, the electric lift 14 in the intelligent mechanical execution unit precisely drives the lifting water tank 13 to rise and fall, thereby dynamically adjusting the elevation of the overflow outlet 16 to match the calculated optimal pressure-limiting water level. In this way, the groundwater level in the underground drainage structure layer is precisely controlled below the dynamically adjusted pressure-limiting water level, effectively balancing the buoyancy of groundwater on the station structure floor slab 1 while simultaneously controlling the settlement of the surrounding strata. This closed-loop control mechanism based on real-time data and an optimization model enables the entire anti-buoyancy system to adaptively adjust according to environmental changes and structural responses, significantly improving the precision and intelligence of the anti-buoyancy strategy and solving the problem that traditional fixed threshold control strategies cannot dynamically balance anti-buoyancy safety and settlement control.

[0119] In a preferred embodiment of the present invention, the active anti-buoyancy activation probability is determined based on the time-varying statistical characteristics of the groundwater level, and its calculation method is as follows:

[0120] ;

[0121] in For real-time groundwater levels, To limit the water level, For integration variables, Represents possible groundwater level values. This is the average groundwater level. This represents the standard deviation of the groundwater level.

[0122] In this embodiment, the active anti-buoyancy start probability Determining groundwater levels based on time-varying statistical characteristics refers to the probability that the actual groundwater level will exceed a given pressure limit. This calculation considers the randomness and statistical regularity of groundwater level changes over time, rather than simply representing a fixed or instantaneous value. This method aims to more accurately quantify the risk of groundwater level fluctuations, providing more reliable input for optimizing dynamic pressure limit models, thus enabling anti-buoyancy control strategies to adapt to constantly changing groundwater hydrological conditions. For example, historical groundwater level data can be statistically analyzed using long-term monitoring data to establish a probability distribution model to capture its time-varying characteristics; or, by combining hydrogeological models and numerical simulations, the possible distribution of future groundwater levels can be predicted, and a probabilistic assessment can be performed based on this prediction.

[0123] The above formula is used to calculate when the groundwater level exceeds a certain pressure limit level. The probability is calculated by integrating the probability density function of a normal distribution. It represents the probability that, assuming the groundwater level follows a normal distribution, the water level is above the pressure limit level. The cumulative probability is calculated using a mathematically rigorous method to quantify the risk of proactive anti-buoyancy initiation, incorporating the randomness of groundwater levels for a more scientific and accurate risk assessment. This integral can be implemented in the calculation module of the hierarchical decision-making center using numerical integration methods, such as the trapezoidal rule, Simpson's rule, or Gaussian integral; alternatively, it can be calculated by consulting a standard normal distribution table or using the cumulative distribution function (CDF) in a statistical software library, after standardizing the original groundwater level data for querying or calculation.

[0124] in, Real-time groundwater level refers to the current groundwater level height as monitored in real time by sensors such as water level gauges; The pressure-limiting water level refers to the critical water level calculated by the graded decision-making center based on the dynamic pressure-limiting model, which is used to guide drainage operations. Let be the integral variable, representing any possible value of the groundwater level in the probability integral; The average groundwater level refers to the average groundwater level over a certain period of time, reflecting the overall trend of groundwater levels. The standard deviation of groundwater level refers to the degree of fluctuation or dispersion of groundwater level over a certain period of time, reflecting the randomness of groundwater level. These parameters are key inputs for constructing and calculating the probability of active anti-buoyancy initiation. Real-time groundwater level Real-time data is collected by water level gauges in a multi-field sensing network. and These statistical parameters can be obtained through statistical analysis of historical water level data, such as by using a sliding window average or an exponentially weighted average to dynamically update them. It is calculated by the hierarchical decision-making center based on the dynamic pressure limiting model.

[0125] This application's solution addresses the problem of inaccurate probability assessment in traditional methods by closely integrating the calculation of active anti-buoyancy initiation probability with the time-varying statistical characteristics of groundwater level. The dynamic pressure-limiting model built into the hierarchical decision-making center no longer relies solely on instantaneous water level or fixed thresholds when calculating the optimal pressure-limiting water level, but instead considers the long-term statistical regularity and random fluctuations of groundwater level. Specifically, by analyzing real-time groundwater level... By statistically analyzing long-term monitoring data, the average groundwater level can be obtained. and standard deviation These parameters precisely describe the time-varying statistical characteristics of groundwater levels. Based on this, the probability density function of a normal distribution is used to analyze the groundwater level from the pressure-limiting water level. By integrating to infinity, the exact calculation was obtained that the groundwater level exceeded the pressure limit level. probability This probability value serves as a key input parameter in the dynamic pressure-limiting model, enabling the model to more accurately assess the risk of initiating proactive anti-buoyancy measures. This probabilistic calculation method based on time-varying statistical characteristics, combined with real-time data collection of water level, settlement, and rainfall parameters from a multi-field sensing network and the dynamic control capabilities of intelligent mechanical actuators, forms a closed-loop intelligent anti-buoyancy system. The hierarchical decision-making center can calculate a more reasonable and optimal pressure-limiting water level based on more accurate risk assessment results and other constraints. For example, when groundwater levels fluctuate significantly, the system can identify this volatility and adjust the pressure-limiting water level accordingly, avoiding unnecessary settlement due to excessive drainage or anti-buoyancy risks due to insufficient drainage. This accurate probabilistic assessment is the foundation for achieving the optimization objective of the dynamic pressure-limiting model in the hierarchical decision-making center, ensuring a dynamic balance between anti-buoyancy safety and settlement control.

[0126] In a preferred embodiment of the present invention, the hierarchical decision-making center executes the following hierarchical control strategy based on the calculation results of the dynamic pressure limiting model and real-time monitoring data:

[0127] Normal regulation: when and At that time, the variable frequency drainage pump set is controlled to operate at the set water level; The current pressure limit water level (i.e., the level obtained in the previous optimization) );

[0128] Heavy rain warning and control: When the rain gauge detects that the rainfall intensity R(t) exceeds the heavy rain warning threshold, the electric lift 14 is controlled to drive the lifting water tank 13 to descend, lower the elevation of the overflow outlet 16, and drain water in advance to free up storage capacity;

[0129] Settlement priority control: When the hydrostatic level detects settlement At the same time, the electric lift 14 drives the lifting water tank 13 to rise, raising the elevation of the overflow port 16 and reducing the drainage volume to control the development of settlement.

[0130] During emergency control, when the water level reaches the structural anti-buoyancy limit level, the following action will be taken: control the variable frequency drainage pump set to drain water at full capacity.

[0131] In this embodiment, the hierarchical decision-making center is the core control unit of the entire active and passive anti-buoyancy system. Its function is to comprehensively analyze real-time monitoring data from multiple sensing networks (such as water level gauges, hydrostatic levels, rain gauges, etc.) and, in conjunction with the calculation results of the built-in dynamic pressure limiting model, intelligently select and execute the most suitable drainage control strategy. Its implementation can include: using a high-performance industrial controller as the hardware platform, with a built-in embedded operating system and decision algorithm module; or using a distributed control system based on cloud computing or edge computing, receiving data and issuing instructions via the network.

[0132] Normal operation control is the basic drainage strategy of the system under normal operating conditions. When environmental conditions are stable and the structure is safe, the hierarchical decision-making center will instruct the variable frequency drainage pump set to drain water according to a preset, relatively stable water level target. This set water level can be a fixed value or a dynamic target value preset based on historical data or seasonal changes. The implementation methods can include: the variable frequency drainage pump set adjusting the pump's operating frequency and power according to the real-time water level feedback from the water level gauge, using a PID controller or other closed-loop control algorithm to maintain the water level in the collection tank 4 within the set range; or, the hierarchical decision-making center directly sending start / stop and power adjustment commands to the variable frequency drainage pump set, so that it meets the set water level requirements while also optimizing energy consumption.

[0133] Rainfall pre-emptive regulation is a proactive prevention strategy designed to address the potential risk of a rapid rise in groundwater levels. When the rainfall intensity R(t) detected by the rain gauge reaches or exceeds a preset rainstorm warning threshold, the tiered decision-making center immediately activates this strategy to pre-emptively lower the water level in the collection tank 4, creating sufficient storage capacity for the upcoming large infiltration of rainwater, thereby effectively preventing excessive buoyancy caused by a rapid rise in groundwater levels. Implementation methods may include: the tiered decision-making center sending a descent command to the electric lift 14, which, through a threaded transmission mechanism, moves the lifting water tank 13 downwards, thereby lowering the elevation of the overflow outlet 16. This allows water in the collection tank 4 to be discharged into an external variable frequency drainage pump unit through the overflow outlet 16 and the flexible drainage hose 17, achieving pre-emptive drainage; or, the electric lift 14 can drive the lifting water tank 13 to different preset elevations according to the warning level, adapting to different levels of rainstorm warnings. Settlement priority control is a structural protection strategy used to slow down or inhibit further settlement when structural settlement approaches a dangerous threshold by adjusting drainage volume.

[0134] When the static level instrument monitors the structural settlement When the cumulative settlement [S] exceeds 80% of the allowable cumulative settlement in the engineering design, it indicates that the structure may face settlement risk. At this time, the hierarchical decision-making center will activate this strategy. Its function is to reduce the drainage volume, allow the groundwater level to rise appropriately, thereby increasing the buoyancy of the station structure's base slab 1 to offset part of the structure's self-weight and the superstructure load, thus achieving the purpose of controlling settlement. The implementation method may include: the hierarchical decision-making center sends an upward command to the electric elevator 14, which drives the lifting water tank 13 to move upward, raising the elevation of the overflow outlet 16, thereby reducing the drainage volume through the overflow outlet 16 and gradually raising the water level in the collection compartment 4; or, the electric elevator 14 can gradually or in stages raise the elevation of the overflow outlet 16 according to the severity and development trend of settlement, so as to finely control the drainage volume and buoyancy. Emergency control is the system's ultimate guarantee strategy when facing the most severe anti-buoyancy risk.

[0135] When the real-time groundwater level H(t) reaches or exceeds the structural anti-buoyancy limit level, it indicates that the structural anti-buoyancy safety has been seriously threatened. At this time, the hierarchical decision-making center will forcibly activate this strategy. Its function is to drain water at maximum capacity regardless of other conditions, lower the groundwater level as quickly as possible, and ensure the structural anti-buoyancy safety. Implementation methods may include: the hierarchical decision-making center directly sending a full-speed operation command to the variable frequency drainage pump set, causing it to drain water at maximum power and flow rate, while ignoring the limitations of other control strategies; or, while draining at full capacity, the electric lift 14 can also drive the lifting water tank 13 to descend to the lowest position to ensure that the overflow outlet 16 is at the lowest elevation, maximizing drainage efficiency.

[0136] like Figure 4 As shown, a construction method for an active and passive anti-buoyancy structure for a subway station, applied to the aforementioned active and passive anti-buoyancy structure for a subway station, includes the following steps:

[0137] The first step is to excavate the foundation pit to the design elevation, level the foundation soil 5, and construct the transverse partition wall 3 to divide the area below the bottom slab into several water collection compartments 4.

[0138] The second step is to lay the reverse filter protective layer 7, the main drainage layer 8, the secondary drainage layer 9 and the flexible permeable pipe 10 in sequence in the water collection compartment 4 to form an underground water collection and drainage structure layer.

[0139] The third step is to pour the waterproof isolation layer 11, the bottom plate protective layer 12 and the station structure bottom plate 1, and reserve installation space at the position of the station structure bottom plate 1;

[0140] The fourth step is to install the intelligent mechanical actuator in the reserved cavity 2 and connect it to the water collection compartment 4;

[0141] The fifth step is to deploy various sensors in the multi-field sensing network, install the hierarchical decision-making center, and complete system debugging.

[0142] In this embodiment, the construction method of this application ensures the effective construction and functional realization of the active and passive anti-buoyancy structure of the subway station through orderly and meticulous steps. First, the excavation of the foundation pit, the leveling of the foundation soil 5, and the construction of the transverse partition wall 3 lay a solid and zoned foundation for the entire anti-buoyancy structure. The excavation of the foundation pit to the design elevation and the leveling of the foundation soil 5 ensure the stability and uniformity of the subsequent structural layer laying.

[0143] Secondly, in the second step, a reverse filter protective layer 7, a main drainage layer 8, a secondary drainage layer 9, and a flexible permeable pipe 10 are sequentially laid in each water collection compartment 4, thereby constructing an efficient underground water collection and drainage structure layer. The reverse filter protective layer 7 effectively prevents fine particles from the foundation soil 5 from clogging the drainage system, ensuring unobstructed drainage channels. The main drainage layer 8 and the secondary drainage layer 9 provide strong drainage capacity, ensuring that groundwater can be quickly collected. The reasonable arrangement of the flexible permeable pipe 10 accurately guides the collected groundwater to the preset water collection point and finally connects to the reserved cavity 2, forming a complete groundwater collection and diversion path, greatly improving drainage efficiency and avoiding the problem of efficiency being affected by improper laying of the drainage layer.

[0144] Next, the third step involved pouring the waterproof isolation layer 11, the base slab protective layer 12, and the station structure base slab 1, thus completing the enclosure and protection of the main structure. The waterproof isolation layer 11 ensures that groundwater will not penetrate into the interior of the station structure, while the base slab protective layer 12 provides physical protection for the waterproof isolation layer 11.

[0145] The fourth step involves installing an intelligent mechanical actuator within the reserved cavity 2 and connecting it to the water collection compartment 4. This step is crucial for achieving coordinated active and passive anti-buoyancy control; the installation of the intelligent mechanical actuator provides the hardware foundation for dynamically adjusting the groundwater level. Through its connection to the water collection compartment 4, the intelligent mechanical actuator can directly act on the groundwater within the compartment, achieving precise control of the pressure-limiting water level.

[0146] Finally, the fifth step involves deploying various sensors within the multi-field sensing network, installing the hierarchical decision-making center, and completing system debugging. The sensors in the multi-field sensing network can collect key data such as water level, settlement, and rainfall in real time and comprehensively, providing accurate input information to the hierarchical decision-making center and avoiding monitoring failures caused by incorrect sensor deployment. The hierarchical decision-making center, acting as the "brain" of the entire system, intelligently calculates the optimal pressure-limiting water level based on this real-time data and a built-in dynamic pressure-limiting model, and issues control commands to the intelligent mechanical execution unit to achieve dynamic regulation of the groundwater level.

[0147] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A passive and active anti-buoyancy structure for subway stations, characterized in that, include: The underground drainage structure layer is located below the station structure floor slab (1); The intelligent mechanical execution unit is installed in the reserved cavity (2) of the station structure bottom plate (1) and is connected to the underground drainage structure layer; A multi-field sensing network, including multiple sensors deployed in the underground drainage structure layer, station structure and surrounding strata; The hierarchical decision-making center is electrically connected to the multi-field sensing network and the intelligent mechanical execution unit, respectively. It calculates the optimal pressure limit water level based on the dynamic pressure limit model and controls the intelligent mechanical execution unit to perform corresponding actions. The hierarchical decision-making center has a built-in dynamic pressure limiting model, which is used to calculate the optimal pressure limiting water level based on real-time monitoring data and generate control commands. The objective function of the dynamic pressure limiting model is: ； The constraints are: , , ; in To limit the water level, To actively resist buoyancy and start-up probability, To predict settlement, To regulate the allowable cumulative settlement, This is the water level influence coefficient. This is the settlement influence coefficient. , For the permissible active anti-buoyancy start probability, The cumulative settlement allowed by the engineering design. For drainage capacity, This refers to groundwater seepage flow. Indicates taking the objective function The independent variable corresponding to the minimum value The value, This is the optimal pressure-limiting water level.

2. The active and passive anti-buoyancy structure for subway stations according to claim 1, characterized in that, A transverse partition wall (3) is set at equal intervals along the longitudinal direction of the station to divide the space below the station structure floor slab (1) into several independent water collection compartments (4). The top of the water collection compartments (4) is covered with a waterproof isolation layer (11). The height of the transverse partition wall (3) extends from the surface of the foundation soil (5) to the bottom surface of the waterproof isolation layer (11).

3. The active and passive anti-buoyancy structure for subway stations according to claim 2, characterized in that, The interior of each of the water collection compartments (4) is provided with, from bottom to top, the following: The filter protection layer (7) is laid on the surface of the foundation soil (5) and is composed of geotextile and medium-coarse sand; The main drainage layer (8) is laid on top of the reverse filter protective layer (7) and adopts a three-dimensional composite drainage network; The secondary drainage layer (9) is laid on top of the main drainage layer (8), using graded crushed stone and with flexible permeable pipes (10) buried inside it. The flexible permeable pipe (10) is arranged longitudinally along the station, and its lower end faces the preset water collection point at the lowest point of the bottom surface of the water collection compartment (4). The upper end of the flexible permeable pipe (10) is connected to the reserved cavity (2). A base plate protective layer (12) is poured on top of the waterproof isolation layer (11), and the station structure base plate (1) is poured on top of the base plate protective layer (12).

4. The active and passive anti-buoyancy structure for subway stations according to claim 3, characterized in that, Each water collection compartment (4) is equipped with a set of intelligent mechanical actuators, the intelligent mechanical actuators including: The lifting water tank (13) is set in the reserved cavity (2) and is partially submerged in the water of the water collection compartment (4); An electric lift (14) is installed on the top of a reserved cavity (2). Its output shaft is fixedly connected to a threaded shaft that passes through the connecting seat of the lifting water tank (13) and is threadedly connected. The connecting seat of the lifting water tank (13) is vertically slidably connected to the reserved cavity (2). A flexible water inlet pipe (15) connects the bottom of the liftable water storage tank (13) to the reserved cavity (2); An overflow outlet (16) is located on the side wall of a liftable water tank (13) and is connected to a variable frequency drainage pump set of an external station via a flexible drainage hose (17).

5. The active and passive anti-buoyancy structure for subway stations according to claim 4, characterized in that, The multi-field sensing network includes: Water level gauges are installed in each water collection compartment (4) and in the observation well outside the foundation pit to collect real-time water level data. ; A static level is installed on the station structure base plate (1) and the surrounding ground surface to collect settlement data S(t); A rain gauge, installed on the ground at the entrance of the station ventilation shaft, is used to collect rainfall intensity R(t); An electromagnetic flow meter is installed on the outlet pipe of a variable frequency drainage pump unit to collect drainage flow rate Q(t). All sensors are electrically connected to the hierarchical decision-making center via a data acquisition module.

6. The active and passive anti-buoyancy structure for subway stations according to claim 5, characterized in that, The active anti-buoyancy activation probability is determined based on the time-varying statistical characteristics of the groundwater level, and its calculation method is as follows: ； in For real-time groundwater levels, To limit the water level, For integration variables, Represents possible groundwater level values. This is the average groundwater level. This represents the standard deviation of the groundwater level.

7. The active and passive anti-buoyancy structure for subway stations according to claim 6, characterized in that, The hierarchical decision-making center executes the following hierarchical control strategies based on the calculation results of the dynamic pressure limiting model and real-time monitoring data: Normal regulation: when and At that time, the variable frequency drainage pump set is controlled to operate at the set water level. The result of the previous round of optimization ; Rainstorm warning control: When the rain gauge detects that the rainfall intensity R(t) exceeds the rainstorm warning threshold, the electric lift (14) is controlled to drive the lifting water tank (13) to descend, reduce the elevation of the overflow outlet (16), and drain water in advance to free up storage capacity; Settlement priority control: When the hydrostatic level detects settlement At the same time, the electric lift (14) drives the lifting water tank (13) to rise, raising the elevation of the overflow port (16) and reducing the drainage volume to control the development of settlement; During emergency control, when the water level reaches the structural anti-buoyancy limit level, the following action will be taken: control the variable frequency drainage pump set to drain water at full capacity.

8. A construction method for an active and passive anti-buoyancy structure for a subway station, applied to the active and passive anti-buoyancy structure for a subway station as described in any one of claims 1-7, characterized in that, Includes the following steps: The first step is to excavate the foundation pit to the design elevation, level the foundation soil (5), and construct the transverse partition wall (3) to divide the area below the bottom slab into several water collection compartments (4). The second step involves laying a reverse filter protective layer (7), a main drainage layer (8), a secondary drainage layer (9), and a flexible permeable pipe (10) in sequence within the water collection compartment (4) to form an underground water collection and drainage structure layer. The third step is to pour the waterproof isolation layer (11), the bottom plate protective layer (12) and the station structure bottom plate (1), and reserve installation space at the position of the station structure bottom plate (1); The fourth step is to install the intelligent mechanical actuator in the reserved cavity (2) and connect it with the water collection compartment (4); The fifth step is to deploy various sensors in the multi-field sensing network, install the hierarchical decision-making center, and complete system debugging.

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