Double control system based on water discharge anti-floating and underground buoyancy dynamic balance

Abstract

This invention relates to the field of building construction technology. To address the technical problem of anti-buoyancy in underground structures under complex hydrogeological conditions, this invention discloses a dual-control system based on drainage anti-buoyancy and dynamic balance of underground buoyancy. The system includes a drainage unit located below the basement floor slab, comprising a drainage ditch or drain pipe to collect and divert groundwater; a sump well connected to the drainage unit to collect the collected groundwater; a drainage pipeline connected at one end to the sump well and at the other end to a rainwater storage tank or municipal drainage network to discharge the groundwater from the sump well; a submersible pump installed in the sump well to discharge groundwater through the drainage pipeline; and an automatic control device electrically connected to the submersible pump to automatically start and stop the pump based on the water level signal in the sump well. The anti-buoyancy control water level of the system is set below the level that can be balanced by the structure's self-weight and additional loads, achieving dual anti-buoyancy control through a combination of structural self-weight, additional loads, and active drainage.

Description

Technical Field

[0001] This invention relates to building construction, and more particularly to a dual-control drainage anti-buoyancy system based on the dynamic balance of drainage anti-buoyancy and underground buoyancy, used to solve the anti-buoyancy problem of underground structures under complex hydrogeological conditions, and to realize an intelligent and dynamic control system. Background Technology

[0002] With the increasing development of urban underground space, the threat posed by groundwater buoyancy to the safety of underground structures is becoming increasingly prominent. Traditional anti-buoyancy measures mainly rely on "passive anti-buoyancy" methods such as anti-uplift piles, anti-buoyancy anchors, or counterweight ballast, which have limitations such as high cost, complex construction, and difficulty in adapting to dynamic changes in water level. In recent years, "active anti-buoyancy" technologies have gradually emerged, among which the drainage and pressure reduction method, which lowers the groundwater level or releases water pressure on the foundation slab by setting up drainage facilities, has become an effective means.

[0003] However, existing anti-buoyancy systems generally suffer from the following key problems: First, the water level determination is inaccurate. In urban renewal or complex built-up area projects, groundwater recharge sources are diverse (such as rainwater infiltration, drainage from surrounding foundation pits, leakage from municipal pipe networks, and water obstruction from railway subgrades), and hydrogeological conditions are significantly disturbed by human engineering activities, making it difficult to accurately determine the anti-buoyancy design water level. If the design water level is too high, it will lead to over-design of the structure and increased costs; if it is too low, there is a risk of structural floating, cracking, or even instability.

[0004] Second, the control response is lagging. Traditional drainage systems are mostly single-path and manually controlled, unable to intelligently adjust according to real-time water pressure and level, and difficult to coordinate with sponge city and municipal drainage systems, resulting in water waste or poor drainage.

[0005] Third, there is a lack of dynamic balancing mechanism. The existing system fails to organically combine "water discharge and pressure reduction" with "structural self-weight balancing" to form a closed-loop, dynamic anti-buoyancy control system.

[0006] Therefore, there is an urgent need to develop an anti-buoyancy technology system that integrates accurate water level determination, intelligent dynamic control, and multi-path coordinated discharge to improve the safety, economy, and sustainability of underground engineering projects. Summary of the Invention

[0007] The purpose of this invention is to provide a dual-control system based on the dynamic balance of drainage anti-buoyancy and underground buoyancy, aiming to solve the above-mentioned technical problems and realize the scientific determination of the anti-buoyancy design water level and the automated, multi-path, and collaborative management of the drainage process.

[0008] The foundation's anti-buoyancy force is provided by the structure's self-weight and additional loads, and the anti-buoyancy control water level is set below the equilibrium water level. When the groundwater level rises and exceeds the anti-buoyancy control water level, the groundwater flows into the sump through the drainage blind ditch or drainage pipe. When the water level in the sump reaches the submersible pump's start-up water level, the automatic control device starts the submersible pump to drain the water. After the discharged groundwater is confirmed to meet the water quality standards, it is discharged into the rainwater storage tank or municipal drainage network. When the water level in the sump drops to the pump stop water level, the submersible pump automatically shuts off, completing the water discharge and pressure reduction process.

[0009] To achieve the above objectives, this invention provides a dual-control system based on the dynamic balance of drainage and anti-buoyancy in the underground environment, used to control the water pressure below the basement floor slab to prevent structural uplift and damage, comprising: A drainage unit, located below the basement floor slab, includes a drainage ditch or drain pipe for collecting and diverting groundwater; at least one sump, connected to the drainage unit, for collecting the collected groundwater; a drainage pipe, one end connected to the sump and the other end connected to a rainwater storage tank or municipal drainage network, for discharging groundwater from the sump; a submersible pump, installed in the sump, for discharging groundwater through the drainage pipe; and an automatic control device, electrically connected to the submersible pump, for automatically starting and stopping the submersible pump based on the water level signal in the sump. The anti-buoyancy control water level of the system is set below the critical water level that can be balanced by the self-weight of the basement structure and the additional load. It provides passive anti-buoyancy force through the self-weight of the structure and the additional load, while actively lowering the groundwater level through water discharge, thus achieving dual anti-buoyancy control that combines passive and active methods.

[0010] Furthermore, the automatic control device includes a water level sensor and a control cabinet. The water level sensor is used to monitor the water level in the collection well in real time and transmit the water level signal to the control cabinet. When the water level is higher than the preset start water level, the control cabinet automatically starts the submersible pump. When the water level drops to the preset stop water level, the control cabinet automatically shuts down the submersible pump.

[0011] Furthermore, drainage blind ditches or drainage pipes are evenly laid under the basement floor slab and connected to the surrounding water diversion system to form a continuous groundwater drainage network.

[0012] Furthermore, the drainage blind ditches or drainage pipes are evenly laid out below the basement floor slab. Their spacing and direction are optimized according to the groundwater seepage path, soil permeability coefficient, and basement plan shape to ensure that groundwater can be efficiently collected and orderly drained. At the same time, the drainage blind ditches or drainage pipes are effectively connected with the water guiding system set around the basement, such as the surrounding seepage drainage pipes, side wall drainage holes, or external water collection channels, to form a complete, continuous, and interconnected groundwater drainage network, thereby improving the reliability and stability of the overall anti-buoyancy system.

[0013] Furthermore, the drainage pipeline is equipped with a water quality testing unit to monitor the quality of the discharged groundwater and ensure that the water discharged into the rainwater storage tank or municipal drainage network meets the discharge standards.

[0014] Furthermore, additional loads include one or more combinations of soil cover loads, building service loads, or structural counterweights.

[0015] Furthermore, the water collection well is equipped with an inspection port and a protective cover for easy maintenance and repair.

[0016] Furthermore, the construction method for drainage blind drains includes the following steps: After the foundation pit support, water cutoff curtain and foundation pit excavation are completed, the blind drain positioning line is laid out and the trench is excavated. The bottom surface and side walls of the trench are manually leveled and compacted before the lower layer of geotextile is laid. A layer of crushed stone is laid on the lower layer of geotextile, and plastic blind pipes are buried in the crushed stone layer. Then, the upper layer of geotextile is covered, so that the crushed stone and plastic blind pipes are completely wrapped by the geotextile. A colored striped fabric is laid on top of the upper geotextile to form a waterproof membrane. The colored striped fabric extends outward by no less than 600mm in the direction perpendicular to the blind drain and is stitched together using the overlock method. After confirming that the top elevation of the blind drain is consistent with the bottom elevation of the subgrade, pour the basement subgrade on top of the tarpaulin. During construction, prevent the tarpaulin from being damaged and prevent cement slurry from seeping into the blind drain.

[0017] Furthermore, the construction of blind drains is carried out before the basement floor slab and foundation; when the spacing between local foundations is small, the elevation of the blind drains is locally lowered, and it is ensured that the transition section of the elevation difference is continuous, without breakage or blockage; the excavation depth at the connection between the blind drain and the sump or drainage pipe is adjusted according to the connection requirements to ensure effective water flow.

[0018] Furthermore, geotextile laying must be carried out on non-rainy days. During laying, it should be smooth, moderately tight, and closely adhered to the soil of the trench wall without wrinkles. If the geotextile is damaged, it must be repaired with a patch with an area not less than 4 times the damaged area, and the overlap width should not be less than 500mm. When there is no clean and flat working surface at the bottom of the foundation pit, a sealing layer should be constructed first, and then a blind drain system should be constructed on the layer.

[0019] Specifically, the aforementioned dual-control system is a dynamic balance system integrating monitoring, control, and drainage, and its composition is as follows: Water and pressure control subsystem: consists of drainage blind ditches (pipes), sump wells and drainage pipes arranged below the basement floor slab.

[0020] Drainage blind drains (pipes): Rectangular trenches are used, filled with crushed stone with a particle size of 12~20mm and wrapped with geotextile, with two 200mm diameter plastic blind pipes installed inside. The blind drains are arranged in a crisscross pattern along the bottom of the basement floor slab, avoiding structural columns, with a slope of not less than 0.3% to ensure smooth water flow.

[0021] Sump pit: Located at the edge of the basement floor slab or a designated location, connected to the blind drain. The pit is equipped with a submersible pump and an emergency submersible pump, and a control cabinet.

[0022] Drainage pipe: connects the water collection well to the external drainage system.

[0023] Intelligent monitoring and control subsystem: Water pressure and level monitoring device: A water pressure monitoring pipe that also serves as a pressure relief pipe is buried in the middle or key location of the base plate. This pipe can be used to monitor the water pressure under the base plate and serve as an emergency pressure relief channel. When the monitored water pressure exceeds the preset safety value (e.g., 30 kPa), the system automatically opens the pressure relief valve.

[0024] Water level control in the sump: The submersible pump in the sump is equipped with a control cabinet. When the water level in the sump is not higher than the starting water level, the submersible pump will automatically shut off; when the water level is higher than the starting water level, the submersible pump will automatically turn on.

[0025] Multipath drainage control subsystem: Routine drainage: When the water level in the collection well reaches the anti-buoyancy control level, the conventional submersible pump is started to pump the groundwater to the manifold connected to the rainwater storage tank of the sponge city.

[0026] Emergency drainage: When the submersible pump or system pipeline fails and the water level in the sump reaches 0.2m above the anti-buoyancy control level, the emergency submersible pump will start and pump the excess water to the municipal stormwater network.

[0027] Emergency drainage for waterlogging: In the event of extreme waterlogging and inability to drain water into the municipal pipe network, the waterlogging prevention valve can be manually opened to drain the water into the slope drainage ditch.

[0028] Remote monitoring platform: An optional anti-floating water damage monitoring platform can be installed to realize data management, visualization and remote control.

[0029] Seepage Prevention and Backfilling Subsystem This subsystem is used to reduce the supply of external water to the basement and is a prerequisite for the effective operation of the entire system.

[0030] Backfilling of the trench: In the trench between the basement exterior wall and the support structure, fluidized solidified soil is used for backfilling. This material has good seepage prevention performance and stability, and can effectively block the infiltration of surface water and shallow groundwater.

[0031] Water-stop curtain: A water-stop curtain (such as jet grouting piles) is set around the foundation pit to further cut off the replenishment of deep groundwater.

[0032] Under complex hydrogeological conditions, the scientific and precise determination of the anti-buoyancy design water level, anti-buoyancy design water level, and anti-buoyancy control water level for each area includes the following steps: A comprehensive analysis was conducted to assess the impact of the site's original topography, historical hydrological data, and surrounding engineering activities (such as railway construction and foundation pit excavation) on groundwater drainage paths. This analysis, combined with observation data from previous groundwater remediation surveys, determined the highest possible water levels for different sides of the site (e.g., northeast, southeast, northwest, and southwest). For example, in a certain urban renewal project, analysis determined that the anti-buoyancy design water level on the northeast side was 59m on the east side and 56m on the west side.

[0033] When using a seepage barrier to isolate the surrounding shallow groundwater recharge, the water level is determined based on discharge volume calculations and a comprehensive review of economic efficiency and safety. This water level is used for discharge volume calculations under daily operating conditions and is a core parameter for system operation.

[0034] The structural self-weight equilibrium water level refers to the water level at which the self-weight and additional load of the structure above the foundation slab reach equilibrium with the water pressure below the foundation slab. For example, in an industrial park project, the water level is 52.80m in the four-story basement area and 55.80m in the three-story basement area.

[0035] The anti-buoyancy control water level, the final target water level during the building's commissioning period, should meet the structural self-weight balance water level and be selected in conjunction with dual-control drainage anti-buoyancy measures. This water level is typically lower than the structural self-weight balance water level and serves as the trigger threshold for the automatic start-stop system. For example, in an industrial park project, the water level should not exceed 51.30m in the four-story basement area and 54.80m in the three-story basement area.

[0036] The dual-control system based on dynamic balance of water discharge anti-buoyancy and underground buoyancy provided by this invention has the following advantages: By comprehensively analyzing multi-source hydrological data, the system achieves scientific, zoned, and precise determination of the anti-buoyancy water level, avoiding design deviations caused by traditional experience-based estimations. It has the functions of automatic monitoring, automatic start-up and shutdown, and automatic switching of drainage paths, and can dynamically adjust according to real-time water pressure and water level without manual intervention, with a rapid response. The system organically combines the active anti-buoyancy of "water discharge and pressure reduction" with the passive anti-buoyancy of "structural self-weight", forming a closed-loop dynamic balance system to ensure that the structure is in a safe state under any working condition.

[0037] Compared to the large-scale installation of anti-uplift piles or counterweights, this system has a lower construction cost and lower operation and maintenance costs. Simultaneously, it introduces discharged groundwater into sponge city systems or municipal pipe networks, achieving water resource recycling and being environmentally friendly. It features three drainage pathways: conventional drainage, emergency drainage, and flood drainage, along with dual protection from both conventional and emergency pumps, greatly improving the system's reliability and fault tolerance. It is particularly suitable for the renovation of old urban areas with large groundwater level fluctuations, complex hydrogeological conditions, urban renewal projects, and newly constructed large-scale underground space projects. Attached Figure Description

[0038] Figure 1 A cross-sectional view of the dual-control anti-buoyancy structure provided by the present invention (AA). Figure 2 A cross-sectional view of the dual-control anti-buoyancy structure BB provided by the present invention; Figure 3 CC cross-sectional view of the dual-control anti-buoyancy structure provided by the present invention; Figure 4 This is an elevation view of the southeast side drainage system provided by the present invention; Figure 5 This is a structural diagram of the hydrophobic layer under the base plate provided by the present invention; Figure 6 This is a diagram illustrating the drainage structure of a gravel blind drain provided by the present invention. Figure 7 A cross plan view of the gravel blind drain provided by the present invention; Figure 8 This is a detailed drawing of the corner connection of the blind drain provided by the present invention; Figure 9 The present invention provides detailed drawings of the temporary drainage ditch and the temporary brick-built water collection pool at the boundary between the first and second phases. Figure 10 This is a detailed drawing of the intersection of the blind drain and the sunken beam provided by the present invention; Figure 11 A detailed drawing of the water collection well provided for this invention; Figure 12 The groundwater level observation well diagram provided for this invention; Figure 13 This is a detailed drawing of the water pressure monitoring pipe provided by the present invention; Figure 14 This is a detailed drawing of the intersection of the conduit and the base plate provided by the present invention. Detailed Implementation

[0039] 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.

[0040] See Figures 1 to 14 This invention provides a dual-control system based on the dynamic balance of drainage anti-buoyancy and underground buoyancy. The dual-control system means that when the groundwater level is higher than the anti-buoyancy control water level, the water head height and water pressure (i.e. buoyancy) under the basement floor slab are regulated by drainage measures to prevent the basement structure from floating or being damaged due to excessive groundwater pressure.

[0041] A combination of drainage and diversion methods is used to actively control the water pressure of the groundwater beneath the basement floor slab, achieving drainage, pressure reduction, and anti-buoyancy. The anti-buoyancy control water level is set below the critical water level that can be balanced by the structure's own weight and additional loads, utilizing the building's own load and additional loads to provide passive anti-buoyancy capability.

[0042] The water and pressure control system includes a drainage ditch or drainage pipe installed below the base plate, a water collection well connected to it, and a drainage pipeline connected to the water collection well, forming a complete groundwater drainage system.

[0043] The system continuously drains groundwater, effectively reducing water pressure below the foundation slab. The discharged groundwater must be tested and meet relevant discharge standards before it can be discharged into rainwater storage tanks or municipal drainage networks.

[0044] The submersible pump in the sump is equipped with a control cabinet. When the water level in the sump is not higher than the starting water level of the submersible pump, the submersible pump will automatically shut down. When the water level is higher than the starting water level, the submersible pump will automatically turn on.

[0045] The construction of blind drains (located below the basement floor slab) includes the following steps: After the construction of the foundation pit support structure and water-cutting curtain is completed, the foundation pit excavation will be carried out. After the foundation pit is excavated, the blind drain is positioned and laid out, and the foundation layout and trenching are completed simultaneously. Lay a layer of geotextile inside the excavated trench; Backfill the geotextile with a layer of crushed stone and bury plastic blind pipes in the crushed stone layer; Cover the gravel and blind drain with another layer of geotextile to form a wrapping and filter protection for the blind drain system. A tarpaulin was laid on top as a temporary isolation or seepage-proof protective layer; Subsequently, the basement floor slab and foundation structure were constructed in sequence, completing the relevant follow-up procedures.

[0046] (1) The blind drain below the basement floor slab should be constructed before the floor slab and the foundation. If the spacing between the foundations is small in some areas, the elevation of the blind drain can be lowered, but the connection at the elevation difference should be ensured, and the blind drain should not be broken or blocked. (2) Excavate the blind ditch according to the blind ditch positioning line. The excavation depth of the connection section with the drainage pipe and the water collection well should be determined according to the situation to ensure effective connection of the blind ditch; (3) Lay blind drains along the positioning line and sew geotextiles. After the blind drains are excavated, the bottom and walls of the drains should be leveled, loose mud should be removed manually, and loose soil should be compacted to ensure that the soil to be protected is dense and flat when the geotextiles are laid. During construction, it is strictly forbidden to damage or contaminate the geotextiles. Geotextile construction must not be carried out on rainy days. (4) The geotextile should be laid smoothly and with appropriate tightness, and should be closely attached to the soil to be protected on the trench wall without any wrinkles.

[0047] Damage should be repaired promptly. The repair area should be more than 4 times the damaged area and the overlap width should be no less than 500mm. The entire gravel blind drain should be wrapped with geotextile.

[0048] (5) Check whether the top elevation of the blind drain is the same as the bottom elevation of the subbase. After leveling, cover the top of the blind drain with colored tarpaulin and seal it into a waterproof membrane. The colored tarpaulin should extend outward by at least 600mm in the direction perpendicular to the blind drain. After checking, pour the subbase. During construction, care should be taken to protect the colored tarpaulin between the concrete subbase and the drainage system. Damage is strictly prohibited. The overlapping of the colored tarpaulin should be sewn using the overlock method. Cement slurry in the concrete must not contaminate the blind drain.

[0049] (5) If there is no clean and flat working surface during the excavation of the foundation pit, it is also possible to use a bedding layer to seal the bottom of the pit before constructing the blind drain system.

[0050] The technical requirements for blind drains are as follows: (1) Set up a rectangular trench under the basement floor slab, avoiding structural columns, which can be adjusted appropriately according to construction requirements; (2) Before the construction of blind drain, the soil layer at the bottom of the blind drain should be compacted or partially replaced to avoid large uneven settlement, which could lead to the breakage of the blind drain pipe and affect the drainage efficiency. (3) The filter material for trench backfilling shall be composed of crushed stone with a particle size of 12-20mm. The total content of mud, clay, clay lumps and organic matter in the filter material shall not exceed 5% (if the content exceeds the standard, it shall be rinsed clean with water); the filter material shall be wrapped with 400g / m2 geotextile, and the overlap length shall not be less than 0.5m; (4) A layer of non-woven geotextile is laid on the top surface of the filter material, with a fold length of 100mm in the middle, to prevent the geotextile from shifting due to the construction and settlement of the upper part. (5) The compaction degree of the filter material (the ratio of the compacted thickness to the loose thickness) shall not exceed 0.9. Backfilling shall be carried out in layers with a layer thickness of 0.2~0.3m. (6) The top surface of the blind drain located below the bottom slab is level with the bottom of the bottom slab cushion layer. It is covered with colored tarpaulin as a grout barrier layer. The colored tarpaulin is 60cm wider than the blind drain on both sides to prevent cement slurry from seeping into the blind drain and clogging the filter material when pouring concrete. (7) At the section where the blind drain crosses the ground beam, the elevation of the top of the blind drain should be lowered for crossing; (8) Two plastic blind pipes with a diameter of 200mm are buried in the gravel blind drain and wrapped with geotextile.

[0051] (9) A stainless steel pipe with an inner diameter of 200mm and a wall thickness of 15mm is used as a sleeve at the junction of the drainage blind ditch and the sump. A plastic blind channel is introduced into a steel collar and then into the water collection well; If there is standing water on the site during construction, the water should be drained. It is strictly forbidden to lay blind drains in muddy water. The joints and vertical intersections between blind drain sections should be tied with wire to prevent displacement during construction.

[0052] In geotextile drainage pipes, geotextile plastic blind pipes should meet the following technical requirements: The construction, connection, and corner treatment of geotextile blind pipes should be carried out according to the manufacturer's provided product specifications and operating methods. Technical specifications of the products should be provided before application in this project, and implementation is only permitted after approval by the design unit; no reverse slope should occur during the laying of drainage blind pipes.

[0053] The construction requirements for the seepage prevention wall (foundation pit and trench filling) are as follows: 1. Meets seepage prevention requirements, cutting off the supply of surface water and shallow groundwater; 2. Filling with materials possessing seepage-proof properties, such as fluidized bed soil or concrete. Considering the high cost of concrete and its susceptibility to shrinkage deformation and fine cracks caused by hydration and gelation, which could affect the waterproofing of the seepage barrier, fluidized bed soil is chosen for filling. During the hardening process, fluidized bed soil exhibits no heat of hydration or shrinkage deformation, does not produce fine cracks, and thus provides excellent seepage prevention. 3. Key points for construction of fluidized solidified soil: (1) Before filling, debris in the foundation pit should be removed and the filling should be carried out symmetrically on both sides or around the perimeter. (2) The cubic compressive strength of the fluidized solidified soil at 28 days is not less than 400 kPa, and the specific gravity of the fluidized solidified soil is not less than 1.5; (3) The organic content of the soil shall not exceed 5%, the maximum particle size of the coarse particles shall not exceed 5 cm, and contaminated soil shall not be used as raw material for solidification soil; (4) The mix proportion of the solidified soil on site should be determined according to the properties of the soil, the type of solidifying agent and the filling requirements; (5) Fluidized solidified soil can be filled by pumping or gravity flow, and its fluidity should meet the filling requirements; (6) Fluidized solidified soil should be filled in layers and sections. The height of each layer should not exceed 3m and the length of each section should not exceed 60m. (7) When the bottom elevation of the fertilizer trench is inconsistent, the filling shall be carried out according to the principle of deep first and shallow second, low first and high second; (8) The slope section near the outer wall is filled with a 1.5m thick solidified soil anti-seepage wall in layers. Plain soil is backfilled behind the anti-seepage wall and compacted to a compaction coefficient of 0.94.

[0054] Monitoring methods include 1. Define the monitoring content: Monitoring of surrounding groundwater level, monitoring of groundwater pressure under the foundation, observation of groundwater level under the foundation, and monitoring of groundwater discharge.

[0055] 2. Arrange the locations of monitoring points 1) Groundwater level monitoring points are set up in the foundation pit and surrounding ground surface. Groundwater level monitoring is carried out using water level observation wells.

[0056] 2) The water level observation point of the bottom slab is arranged at an appropriate position in the middle of the bottom slab, and the observation tube is fixed to the surface of the basement wall.

[0057] 3) The bottom water pressure monitoring point is located at the blind drain location, and is installed via buried steel pipes with the upper end positioned at the basement drainage ditch. A pressure gauge is used for bottom water pressure monitoring, with a range not exceeding 250 kPa and an accuracy sufficient to read pressure changes of 1 kPa. Under continuous heavy rainfall conditions, when the bottom water pressure exceeds the control pressure, the pressure control valve automatically opens to release water and relieve pressure.

[0058] 4) Groundwater discharge monitoring points are set up at the outlet of the submersible pump drainage pipe in the sump, and water meters (flow meters) are used for monitoring.

[0059] 3. Monitoring frequency and time: 1) Groundwater level monitoring: For the first year after the basement is completed, it will be monitored monthly during the rainy season and every two months during the dry season. After one year, it will be monitored every two months during the rainy season and every three months during the dry season. 2) The water pressure at the bottom of the slab is automatically monitored and the changes in water pressure are automatically recorded; 3) No frequency requirement for bottom water level monitoring; 4) The discharge volume should be monitored and recorded once a day from the start of discharge until discharge stops. If the discharge volume is large, the discharge volume monitoring can be adjusted, and the monitoring should be conducted no less than twice a day.

[0060] The dual-control system based on dynamic balance of water discharge anti-buoyancy and underground buoyancy provided by this invention has the following advantages: Precise determination of anti-buoyancy water level under multiple water source recharge: In construction projects, the groundwater on the site is affected by various factors, and the recharge sources are complex. By comprehensively analyzing the project's groundwater recharge survey report and other data, combined with the changes in groundwater discharge and recharge caused by the original topography, railway construction, and surrounding building construction, the anti-buoyancy design water level on each side can be accurately determined.

[0061] The intelligent dual-control drainage and anti-buoyancy system project constructs an intelligent dual-control drainage and anti-buoyancy system. When the groundwater level is higher than the anti-buoyancy control water level, the system automatically starts the drainage operation. A water pressure monitoring pipe, which also serves as a pressure relief pipe, is installed in the middle of the base slab to monitor the water pressure in real time. When the pressure is too high, the valve automatically opens to reduce the pressure. A submersible pump in the collection well, equipped with a control cabinet, automatically starts and stops according to the water level. Simultaneously, the system has multiple drainage paths, allowing water to be introduced into sponge city rainwater storage tanks, municipal pipe networks, or slope drainage ditches, depending on the actual situation.

[0062] The above description is only 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 dual-control system based on water discharge anti-buoyancy and dynamic balance of underground buoyancy, used to control the water pressure below the basement floor slab to prevent structural floating and damage, characterized in that, include: Drainage units, located below the basement floor slab, include drainage blind drains or drainage pipes, used to collect and divert groundwater; At least one collection well, connected to the drainage unit, is used to collect the collected groundwater; The drainage pipe has one end connected to the collection well and the other end connected to a rainwater storage tank or municipal drainage network, and is used to drain the groundwater in the collection well. A submersible pump, installed in the collection well, is used to discharge groundwater through the drainage pipe; An automatic control device, electrically connected to the submersible pump, is used to automatically start and stop the submersible pump according to the water level signal in the collection well. The anti-buoyancy control water level of the system is set below the critical water level that can be balanced by the self-weight of the basement structure and the additional load. It provides passive anti-buoyancy force through the self-weight of the structure and the additional load, while actively lowering the groundwater level through water discharge, thus achieving dual anti-buoyancy control that combines passive and active methods.

2. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The automatic control device includes a water level sensor and a control cabinet; The water level sensor is installed inside the water collection well to monitor the water level in the water collection well in real time and transmit the water level signal to the control cabinet. The control cabinet makes a judgment based on the received water level signal: when the water level is higher than the preset start water level, the control cabinet starts the submersible pump; when the water level drops to the preset stop water level, the control cabinet shuts down the submersible pump.

3. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The drainage blind ditches or drainage pipes are evenly laid out along the basement floor slab and connected to the surrounding water diversion system to form a continuous groundwater diversion network.

4. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The drainage pipeline is equipped with a water quality testing unit to monitor the quality of the discharged groundwater and ensure that the water discharged into the rainwater storage tank or municipal drainage network meets the discharge standards.

5. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The additional loads include one or more combinations of soil cover loads, building service loads, or structural counterweights.

6. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The water collection well is equipped with an inspection port and a protective cover for easy maintenance and repair.

7. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 1, characterized in that, The construction method of the drainage blind ditch includes the following steps: After the foundation pit support, water cutoff curtain and foundation pit excavation are completed, the blind drain positioning line is laid out and the trench is excavated. The bottom surface and side walls of the trench are manually leveled and compacted before the lower layer of geotextile is laid. A layer of crushed stone is laid on the lower geotextile, and a plastic blind pipe is buried in the crushed stone layer. Then, the upper geotextile is covered, so that the crushed stone and the plastic blind pipe are completely wrapped by the geotextile. A colored striped fabric is laid on top of the upper geotextile to form a waterproof membrane. The colored striped fabric extends outward by no less than 600mm in the direction perpendicular to the blind drain and is stitched together using the overlock method. After confirming that the top elevation of the blind drain is consistent with the bottom elevation of the subgrade, pour the basement subgrade on top of the tarpaulin. During construction, prevent the tarpaulin from being damaged and prevent cement slurry from seeping into the blind drain.

8. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy according to claim 7, characterized in that, The construction of the blind drain is carried out before the basement floor slab and foundation. When the spacing between local foundations is small, the elevation of the blind drain is locally lowered, and the transition section of the elevation difference is ensured to be continuous, without breakage or blockage. The excavation depth at the connection between the blind drain and the sump or drainage pipe is adjusted according to the connection requirements to ensure effective water flow.

9. The dual-control system based on dynamic balance of drainage anti-buoyancy and underground buoyancy as described in claim 8, characterized in that, Geotextile laying must be carried out on non-rainy days. When laying, it should be smooth, moderately tight, and closely adhered to the soil of the trench wall without wrinkles. If the geotextile is damaged, it must be repaired with a patch with an area not less than 4 times the damaged area, and the overlap width should not be less than 500mm. When there is no clean and flat working surface at the bottom of the foundation pit, a sealing layer should be constructed first, and then the blind drain system should be constructed on the layer.

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