Yangtze river floodplain area deep foundation pit partition grading intelligent precipitation system and construction method

Abstract

The application belongs to the technical field of dewatering well and provides a long river floodplain area deep foundation pit partition grading intelligent precipitation system, which comprises a dewatering well, a pressure relief well, an observation well and a recharge well, the outer surface of the dewatering well is provided with a filter screen, the dewatering well is provided with filter holes on the surface above the foundation pit excavation surface, the inner surface of the dewatering well is fixedly connected with two symmetrical support rods, the top of the support rod is provided with a limiting support hole, the inside of the support rod is provided with a blocking sliding groove in communication with the inside of the limiting support hole, the inside of the two limiting support holes is slidably connected with a sliding block, the long river floodplain area deep foundation pit partition grading intelligent precipitation system and the construction method can make the sliding block fall on the third guide arc plate, then be guided by the third guide arc plate and fall into the inside of the limiting support hole for positioning and supporting, and realize the position fixation of the first water pump and the filter protection cylinder, so that the first water pump can more stably extract the water flow in the dewatering well.

Description

Technical Field

[0001] This invention relates to the field of dewatering well technology, and more specifically, to a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. Background Technology

[0002] An excavation pit is a pit dug at the foundation design location according to the base elevation and foundation plan dimensions. Before excavation, an excavation plan should be determined based on geological and hydrological data, combined with the conditions of nearby buildings, and waterproofing and drainage work should be carried out.

[0003] Currently, the drainage of the foundation pit mainly relies on the dewatering well and the pressure reduction well 50. However, during the drainage process, the dewatering well uses a suspended first water pump to extract the water flow inside. Due to the suspension of the first water pump, the force generated by the water flow and the operation of the pump body during the operation of the first water pump can easily cause the pump body to shake or even collide with the inner wall of the well, thereby causing damage to the pump body and the inside of the well, and reducing the service life of the pump body. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain includes a dewatering well, a depressurization well, an observation well, and a recharge well. The outer surface of the dewatering well is equipped with a filter screen, and filter holes are formed on the surface of the dewatering well above the excavation face of the foundation pit. Two symmetrical support rods are fixedly connected to the inner surface of the dewatering well. Limiting support holes are formed at the top of the support rods, and blocking sliding grooves communicating with the interior of the limiting support holes are formed inside the support rods. Sliding sliders are slidably connected inside each of the two limiting support holes. A top cover is fixedly connected between the two sliding sliders, and a protective cylinder is fixedly connected to the bottom of the top cover. The interior of the protective cylinder is fixedly... A first water pump is fixedly connected, and a drain pipe extending to the outside of the top cover is fixedly connected to the drain end of the first water pump. A filter protection cylinder is fixedly connected to the bottom of the protective cylinder. The filter protection cylinder has mesh holes. An anti-clogging cleaning component for cleaning the filter protection cylinder is installed inside. A protective pipe is installed inside the dredging well. A stable positioning component for positioning the protective pipe is installed inside the dredging well. Two supporting arc plates are fixedly connected inside the dredging well. A closed positioning and stabilizing component for positioning and fixing the protective pipe and the drain pipe of the first water pump is installed inside the dredging well.

[0006] The present invention is further configured such that: the stable positioning component includes a first guide arc plate, a second guide arc plate, and a third guide arc plate. The surfaces of the first guide arc plate, the second guide arc plate, and the third guide arc plate are all fixedly connected to the inner surface of the drainage well. The first guide arc plate, the second guide arc plate, and the third guide arc plate are arranged sequentially from top to bottom. The downwardly inclined end of the third guide arc plate is fixedly connected to the surface of the support rod. Four support seats are fixedly connected inside the drainage well. The four support seats are arranged in groups of two. A rotating plate is rotatably connected between two support seats in a group through a torsion spring and a shaft. The rotating plate is arranged between the second guide arc plate and the third guide arc plate. A positioning groove is opened on one side of the rotating plate. A guide limiting plate is fixedly connected to the top of the rotating plate. A guide groove is opened on the guide limiting plate. A steel wire rope is fixedly connected to the bottom of the rotating plate. The end of the steel wire rope away from the rotating plate passes through the interior of the third guide arc plate and extends to the exterior of the third guide arc plate.

[0007] A construction method for a zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain includes the following specific operational steps: S1. Set up zoned dewatering units: After the foundation pit is excavated, based on the isolation status of the foundation pit retaining structure against confined water, combined with the stratum lithology, aquifer distribution and sensitivity of the surrounding environment, the foundation pit is divided into three types of areas: areas with completely isolated confined water, areas with partially isolated confined water and areas with unisolated confined water. In areas where confined water is completely isolated, a drainage well is configured; in areas where confined water is partially isolated, a combination of a drainage well and a pressure-reducing well is configured; in areas where confined water is not isolated, a three-in-one configuration of a pressure-reducing well, a drainage well, and an external backup well is used, with the external backup well also serving as a water level observation well. The dewatering well is divided into steel pipe dewatering well and sand-free concrete pipe dewatering well. Both adopt a full-hole filter pipe design and are wrapped with an 80-mesh nylon filter screen. The dewatering well uses limit support holes to position and support the slider, and fix the position of the first water pump and the filter protection cylinder. This allows the first water pump to extract water from the inside of the dewatering well more stably. The anti-clogging cleaning component cleans the outer surface of the filter protection cylinder, which reduces the long-term adhesion of impurities to the filter protection cylinder and prevents the mesh of the filter protection cylinder from clogging. A chamber is formed by the collection frame and the guide plate to store rainwater and soil falling from the external environment, preventing soil from entering the interior of the dewatering well and causing pollution and blockage. S2. Intelligent monitoring unit: Drilling and reinjection wells are equipped with a layered water level monitoring module, a deformation monitoring module, an operation status monitoring module, and a data transmission module in the observation well; The stratified water level monitoring module deploys high-precision water level sensors in the unconfined aquifer, upper confined aquifer, and lower confined aquifer to monitor water levels. The deformation monitoring module includes a ground settlement monitor, pipeline displacement monitor, and retaining structure displacement sensor to monitor ground settlement. The operational status monitoring module installs flow and pressure sensors in each dewatering well and recharge well to monitor water levels and drainage flow rates. The data transmission module uses LoRa wireless transmission technology to upload the data collected by the sensors to the control center database in real time. S3, Dynamic Control Unit: Composed of a data processing module, a numerical model module, a parameter optimization module, and an execution module, it realizes automatic adjustment of precipitation parameters; The data processing module uses the Kalman filter algorithm to reduce noise in the monitoring data and remove environmental interference signals; The numerical model module constructs a three-dimensional groundwater flow model based on MODFLOW and establishes a settlement prediction model by combining Terzaghi's one-dimensional consolidation theory. The model parameters are calibrated through field pumping tests. The model input parameters include the permeability coefficient of unconfined aquifer Kxx=Kyy=0.01m / d, confined aquifer (silty sand) Kxx=Kyy=25m / d, Kzz=12m / d, confined aquifer (pebbles and gravel) Kxx=Kyy=40m / d, Kzz=30m / d, and the initial hydraulic head elevation +7.0m. The parameter optimization module outputs the optimal precipitation flow rate, water level control threshold, and recharge volume parameters in real time based on the excavation progress, water level changes, and settlement data; the execution module automatically adjusts the precipitation parameters through the first, second, third, and fourth water pumps and electric valves. S4. Emergency Support Unit: Includes dual power supply module, reinjection compensation module, piping plugging module and intelligent early warning module; The dual power supply module adopts automatic switching between the main power supply and the backup power supply to ensure continuous operation of the dewatering system; The numerical model module of the dynamic control unit supports real-time iterative updates, calibrating the model parameters every two hours based on the latest monitoring data, and outputting the optimal dewatering plan in stages according to the excavation progress of the foundation pit. The reinjection compensation module is equipped with a water purification device, and the reinjection water source is clean water after rainwater treatment. The piping plugging module includes a graded treatment plan. For minor piping, double fast cement is used for sealing; for moderate piping, double fast cement + polyurethane grouting is used; and for severe piping, a comprehensive treatment plan of pressure reduction + combined grouting is initiated from the backup well outside the pit. The piping plugging module is equipped with dual-fast cement, polyurethane grouting components and high-pressure grouting pump, and comes with a customized plugging tool kit; the intelligent early warning module presets multiple early warning thresholds such as abnormal water level, excessive settlement, and sudden flow changes, and automatically pushes instructions to the emergency response system when an early warning is triggered; S5. Exploration and Modeling Stage: Conduct detailed geotechnical engineering investigation to determine the stratigraphic distribution, aquifer parameters, and surrounding environmental conditions. Use pumping tests to verify hydrogeological parameters and obtain the average permeability coefficient K=18.66m / d. Based on the investigation results, construct a three-dimensional hydrogeological conceptual model and a settlement prediction model. Use hexahedral meshing and vertical subdivision into seven layers to clarify the safe water level threshold and precipitation requirements for each zone. S6. Zonal and graded well completion stage: adopt positive circulation rotary drilling mud wall protection technology, strictly control drilling deviation and well depth deviation; in areas where the confined water is completely isolated, construct dewatering wells first, and after well completion, use submersible pumps to flush the well until the sand content of the water is reached, and conduct sensitivity testing; in areas where the confined water is partially isolated and not isolated, construct depressurization wells and dewatering wells simultaneously, control the well inclination of the depressurization well construction to ≤1°, and the verticality deviation of the filter pipe installation to ≤0.5°; the backup well outside the pit is constructed simultaneously with the main dewatering well to ensure emergency activation efficiency; S7. Intelligent Trial Operation Phase: Install all monitoring sensors and control equipment, conduct a 24-hour group well pumping test, verify the accuracy of the numerical model, and debug the stability of sensor data transmission and the response speed of the actuator; set the safe water level threshold, settlement warning value and flow abnormality threshold for each zone. S8. Dynamic Dewatering Stage: Following the principles of "dewatering on demand, zoned control, and synchronous monitoring," dewatering wells in corresponding areas are opened according to the progress of foundation pit excavation. Monitoring data is received in real time through the dynamic control unit, and the numerical model outputs the optimal dewatering parameters every two hours. The execution module automatically adjusts the flow rates of the first, second, third, and fourth water pumps and the opening of the electric valves. The reinjection compensation module is activated synchronously in sensitive areas to control ground subsidence. Sediment in the wells is cleaned regularly, and a comprehensive equipment overhaul is carried out monthly. S9. Emergency Response Phase: When the water level is detected to be 5% higher than the safety threshold, the number of dewatering wells opened or the water pump flow rate will be automatically increased; when the settlement reaches 80% of the warning value, the precipitation intensity in the corresponding area will be reduced and the recharge volume will be increased; when piping occurs, the backup well outside the pit will be activated immediately to reduce pressure, and the seepage outlet will be sealed with double-fast cement simultaneously. If necessary, polyurethane will be injected to seal the leakage channel; in the event of a power outage, the dual power supply module will automatically switch to the backup power supply, with a switching time of ≤10 minutes. S10, Well Sealing and Protection Phase: Well sealing will be carried out in three phases to ensure the safety of the foundation pit structure and prevent groundwater pollution; S10-1: Before the foundation slab construction, the drainage wells and some observation and backup wells are sealed by "clay backfilling + concrete pouring"; S10-2: After the base plate is completed and reaches the design strength, some pressure relief wells are left for pumping water and anti-buoyancy, while the remaining pressure relief wells adopt the process of "grouting + concrete pouring + steel plate welding". S10-3: After the foundation pit meets the anti-buoyancy requirements, the remaining depressurization wells are sealed. The specific steps are as follows: S10-3-1 Weld an 800mm diameter, 10mm thick waterstop steel plate to the middle of the concrete base slab; S10-3-2. A grouting pipe is lowered into the well to the bottom of the well. S10-3-3 Add sunflower seed chips to a depth of 2m below the bottom plate; S10-3-4 High-pressure grouting until the water level stabilizes; S10-3-5 Pour concrete to 10cm below the bottom slab; S10-3-6 Remove excess well casing, weld the casing opening and apply mortar to level it.

[0008] 1. This invention discloses a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. A slider falls onto a third guide arc plate, and after being guided by the third guide arc plate, it falls into the limiting support hole for positioning and support, thus fixing the positions of the first water pump and the filter protection cylinder. This allows the first water pump to more stably extract water from the drainage well, making the discharge of water from the drainage well smoother. It also reduces the risk of the first water pump colliding with the interior of the drainage well during its descent, thus preventing damage to the drainage well. Furthermore, it reduces the likelihood of the drainage well shaking and causing unstable pumping during operation.

[0009] 2. The present invention provides a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. By moving the clamping positioning plate, the first spring can be compressed and reset. After the protective pipe enters the positioning groove, the clamping positioning plate can tighten the protective pipe to a certain extent under the action of the first spring, and make the protective pipe more stable in the drainage well. This allows the water level detection pressure transmitter inside the protective pipe to detect data more smoothly and ensure the accuracy of the detection data to a certain extent.

[0010] 3. The present invention provides a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. By using a brush to clean the outer surface of the filter protection cylinder, impurities are reduced from adhering to the filter protection cylinder for a certain period of time, thus preventing the mesh of the filter protection cylinder from becoming clogged and reducing the speed at which water flows into the filter protection cylinder. This allows the first water pump to extract water more smoothly, while also providing better protection for the first water pump and extending its service life.

[0011] 4. The present invention provides a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. By detaching the assembly frame from the assembly slot, the device can be disassembled, allowing it to more smoothly protect the drainage well. This also reduces the direct inflow of soil and rainwater from the external environment into the drainage well, preventing blockages and ensuring the first water pump can effectively extract water. This makes it easier for workers to use the device.

[0012] 5. This invention discloses a zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. A flow sensor and pressure sensor are installed in each dewatering well and recharge well via an operational status monitoring module to monitor the water level and drainage flow. Simultaneously, a parameter optimization module outputs the optimal dewatering flow, water level control threshold, and recharge volume parameters in real time based on excavation progress, water level changes, and settlement data. The execution module automatically adjusts the dewatering parameters via a variable frequency first pump and electric valves, thereby achieving automatic drainage and dewatering of the wells and enabling smoother construction of the foundation pit. Attached Figure Description

[0013] Figure 1 This is a flowchart of the control center module of the present invention; Figure 2 This is a schematic diagram of the structure of a zoned and graded intelligent precipitation system for deep foundation pits in the Yangtze River floodplain area according to the present invention; Figure 3 This is a schematic diagram of the structure of the guide plate of the present invention; Figure 4 This is a schematic diagram of the structure of the drainage well of the present invention; Figure 5 This is a schematic diagram of the structure of the second guide arc plate of the present invention; Figure 6 This is a schematic diagram of the rotating plate of the present invention; Figure 7 This is a schematic diagram of the structure of the third blocking rod of the present invention; Figure 8 This is a schematic diagram of the structure of the supporting transmission rod of the present invention; Figure 9 This is a schematic diagram of the structure of the collection frame of the present invention; Figure 10 For the present invention Figure 9 A magnified structural diagram of A in the middle; Figure 11 For the present invention Figure 9 A magnified structural diagram of B in the diagram; Figure 12 This is a schematic diagram of the planar structure of the rotating plate of the present invention; Figure 13 This is a schematic diagram of the pressure-reducing well of the present invention.

[0014] In the diagram: 1. Filter screen; 2. Drainage well; 3. Support rod; 4. Limiting support hole; 5. Brush; 6. Protective cylinder; 7. Sliding block; 8. First water pump; 9. Filter protective cylinder; 10. Top cover; 11. First guide arc plate; 12. Second guide arc plate; 13. Third guide arc plate; 14. Support base; 15. Rotating plate; 16. Steel wire rope; 17. Limiting shaft; 18. Displacement plate; 19. Positioning groove; 20. Guide limiting plate; 21. Telescopic groove; 22. First spring; 23. Tightening positioning plate; 24. Support arc plate; 25. Mounting positioning rod; 26. Assembly groove; 27. Collection frame; 28. Guide plate; 29. ​​Closed positioning plate; 30. Second spring; 31. Transmission plate; 32. Transmission column; 33. Movable groove; 34. Rotating transmission plate; 35. Rotating shaft; 36. Power groove; 37. Gear; 38. Rack; 39. Moving frame; 40. Third spring; 41. Pulling frame; 42. Moving adjustment groove; 43. Protective tube; 44. Impeller; 45. Rotating rod; 46. Support transmission rod; 47. Cleaning rod; 48. Mounting groove; 49. Assembly frame; 50. Pressure-reducing well; 51. Observation well; 52. Second water pump; 53. First water level sensor; 54. Second water level sensor; 55. Third water level sensor; 56. Third water pump; 57. Fourth water pump; 58. Recharge well; 59. Restriction support base; 60. Fourth water level sensor; 61. Controller; 62. First blocking rod; 63. Second blocking rod; 64. Third blocking rod; 65. Blocking sliding groove; 66. Power transmission groove; 67. Blocking block; 68. Baffle. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0016] Example 1, please refer to Figure 2-4This invention provides the following technical solution: a zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain, comprising a dewatering well 2, a pressure-reducing well 50, an observation well 51, and a recharge well 58. By extracting water from the pressure-reducing well 50, the pressure head of the confined aquifer can be reduced. The water level can be monitored through the observation well 51. The recharge well 58 can balance groundwater resources and achieve recycling. A filter screen 1 is installed on the outer surface of the dewatering well 2, which filters the water entering the well. Filter holes are formed on the surface of the dewatering well 2 above the excavation face of the foundation pit, allowing for further filtration of the liquid after filtering by the filter screen 1. The inner surface of the dewatering well 2 is fixed. Two symmetrical support rods 3 are connected. A limiting support hole 4 is formed at the top of each support rod 3. A blocking sliding groove 65 communicating with the inside of the limiting support hole 4 is formed inside each support rod 3. A slider 7 is slidably connected inside each of the two limiting support holes 4. The slider 7 is supported and positioned by the longitudinal groove of the limiting support hole 4. A top cover 10 is fixedly connected between the two sliders 7. A protective cylinder 6 is fixedly connected to the bottom of the top cover 10. A first water pump 8 is fixedly connected inside the protective cylinder 6. A drain pipe extending to the outside of the top cover 10 is fixedly connected to the drain end of the first water pump 8. The drain pipe extends to the outside of the drainage well 2 to discharge the water pumped by the first water pump 8. Simultaneously, the drain pipe is... A flow sensor is installed on the outer surface of the drainage well 2. This flow sensor is existing technology, and its operating principle is known to those skilled in the art. The flow sensor monitors the discharge flow rate of the first water pump 8. A filter protection cylinder 9 is fixedly connected to the bottom of the protective cylinder 6. The filter protection cylinder 9 has mesh holes, which further filter the water drawn by the first water pump 8, thereby reducing damage to the first water pump 8 from impurities and providing better protection. This extends the service life of the first water pump 8 and reduces the likelihood of blockages in the pipes of the first water pump 8 caused by impurities, thus enabling the first water pump 8 to drain water more stably. The inside of the filter cylinder 9 is equipped with an anti-clogging cleaning component for cleaning the filter protection cylinder 9. The inside of the drain well 2 is equipped with a protective pipe 43. The inside of the protective pipe 43 is equipped with a water level detection pressure transmitter. The water level detection pressure transmitter is existing technology, and its operating principle is known to those skilled in the art. The water level detection pressure transmitter can detect changes in the water level inside the drain well 2 through pressure. The inside of the drain well 2 is equipped with a stable positioning component for positioning the protective pipe 43. Two supporting arc plates 24 are fixedly connected inside the drain well 2. The inside of the drain well 2 is equipped with a closed positioning stable component for positioning and fixing the protective pipe 43 and the drain pipe of the first water pump 8. Both the pressure-reducing well 50 and the observation well 51 have filter screens 1 installed on their outer surfaces. The pressure-reducing well 50 has a second water pump 52 installed inside, which extracts water from the well and reduces the water content of the aquifer. The pressure-reducing well 50 also has a fourth water level sensor 60 installed inside, which detects the water level inside. The observation well 51 has a third water pump 56 installed inside, which extracts water from the well. The observation well 51 also has a first water level sensor... The first water level sensor 53, the second water level sensor 54, and the third water level sensor 55 are arranged in descending order of water level, so that the first water level sensor 53, the second water level sensor 54, and the third water level sensor 55 can detect the water level at different positions inside the observation well 51 in a timely manner. The recharge well 58 is equipped with a fourth water pump 57, which can extract water flow. The first pump body 8, the second water pump 52, the third water pump 56, and the fourth water pump 57 are all electrically connected to the controller 61. The first water level sensor 53, the second water level sensor 54, the third water level sensor 55, the third water pump 56, the fourth water pump 57, and the fourth water level sensor 60 are all existing technologies, and their working principles are known to those skilled in the art. One end of the first water level sensor 53 is electrically connected to the controller 61, and one end of the second water level sensor 54, the third water level sensor 55, and the fourth water level sensor 60 are all electrically connected to the controller 61. The controller 61 can receive the detection signals from the first water level sensor 53, the second water level sensor 54, the third water level sensor 55, and the fourth water level sensor 60. Flow sensors are also installed on the drain pipes of the second water pump 52, the third water pump 56, and the fourth water pump 57.

[0017] Please refer to the following: Figure 1 The controller 61 is internally equipped with a control center module. The signal output terminal of the control center module is connected to an intelligent detection unit, a dynamic control unit, and an emergency support unit. The intelligent detection unit includes a stratified water level monitoring module, a deformation monitoring module, an operating status monitoring module, and a data transmission module. The signal input terminal of the stratified water level monitoring module is connected to the signal output terminals of the first water level sensor 53, the second water level sensor 54, the third water level sensor 55, and the fourth water level sensor 60. The signal input terminal of the operating status monitoring module is connected to the signal output terminal of the flow sensor.

[0018] The dynamic control unit includes a data processing module, a numerical model module, a parameter optimization module, and an execution module. The emergency support unit includes a dual power supply module, a reinjection compensation module, a piping and leak plugging module, and an intelligent early warning module.

[0019] When in use, based on the principles of geological matching, functional adaptation, and risk classification, and combined with the type of foundation pit retaining structure, aquifer distribution, and sensitivity of the surrounding environment, fine-grained zoning and dewatering well configuration should be carried out. In the area completely isolated from confined water, the retaining structure is a diaphragm wall with a bottom elevation of -38 to 45.9m, entering a strongly weathered mudstone layer. The completely isolated layer is hydraulically connected to the confined water. At this time, there is no external confined water supply. It is mainly necessary to drain the unconfined water and a small amount of residual confined water in the pit. In the partially isolated confined water area, the retaining structure is a diaphragm wall with a bottom elevation of -38m, entering the silty clay interbedded with silty sand layer (relative to the impermeable layer), partially isolated confined water hydraulic connection, at which point there is a small amount of bypass flow replenishment, and it is necessary to take into account both the drainage well 2 and the depressurization well 51. In areas where the confined water is not isolated, the retaining structure consists of "suspended" structures such as SMW method piles and bored piles, which do not penetrate the lower impermeable layer. The groundwater inside and outside the pit is closely connected hydraulically, and the confined water supply is strong. It is necessary to strengthen depressurization and control of the water level outside the pit. By setting different numbers of dewatering wells 2, depressurization wells 50 and observation wells 51 in different areas, it is possible to achieve zoned and graded dewatering of deep foundation pits in the Yangtze River floodplain area. Through the detection of water level by the first water level sensor 53, the second water level sensor 54, the third water level sensor 55 and the fourth water level sensor 60 and the control of the controller 61, the first water pump 8, the second water pump 52, the third water pump 56 and the fourth water pump 57 can be operated respectively, and intelligent dewatering of the foundation pit can be achieved.

[0020] Example 2, please refer to Figure 3-6 The stable positioning assembly includes a first guide arc plate 11, a second guide arc plate 12, and a third guide arc plate 13. The surfaces of all three guide arc plates are fixedly connected to the inner surface of the drainage well 2. There are two of each of the three guide arc plates, arranged sequentially from top to bottom. The first guide arc plate 11 and the second guide arc plate 12 are staggered in a certain position, as are the second guide arc plate 12 and the third guide arc plate 13. This ensures that when the protective cylinder 6 and the first water pump 8 fall inside the drainage well 2, the slider 7 can only land on the first guide arc plate 11 and the second guide arc plate 12, and is then guided downwards by the first and second guide arc plates 11 and 12 to the third guide arc plate 13. (See also...) Figure 4The downward-sloping end of the third guide arc plate 13 is fixedly connected to the surface of the support rod 3, so that the slider 7 can fall more smoothly into the interior of the limiting support hole 4 for positioning and support after being guided by the third guide arc plate 13. Four support seats 14 are fixedly connected inside the drainage well 2. The four support seats 14 are arranged in groups of two, and the two groups of support seats 14 are respectively set on both sides of the inner surface of the drainage well 2. In one group, the two support seats 14 are rotatably connected to a rotating plate 15 through a torsion spring and a shaft. Under the action of the torsion spring, when the rotating plate 15 is in the vertical state, the torsion spring is in the natural state. A positioning groove 19 is opened on one side of the rotating plate 15, which slides to the fixed position through the protective tube 43. The interior of the positioning groove 19 allows the rotating plate 15 to position the protective tube 43. A guide limiting plate 20 is fixedly connected to the top of the rotating plate 15. The guide limiting plate 20 has a guide groove for guiding the protective tube 43. At the same time, the rotating plate 15 has an arc-shaped groove for positioning the cable and the drain pipe. The positioning groove 19 is located between the two arc-shaped grooves, so that the protective tube 43 can enter the interior of the positioning groove 19 more smoothly through the groove. The rotating plate 15 is located between the second guide arc plate 12 and the third guide arc plate 13. The end of the steel wire rope 16 away from the rotating plate 15 passes through the interior of the limiting support seat 59 and extends to the exterior of the limiting support seat 59. Please see Figure 6-7 A second blocking rod 63 is fixedly connected between the first guide arc plate 11 and the second guide arc plate 12. A 62 is fixedly connected between the second guide arc plate 12 and the third guide arc plate 13. A third blocking rod 64 is fixedly connected to the top of the support rod 3 and to the bottom of the second guide arc plate 12. The second blocking rod 63 connects the first guide arc plate 11 and the second guide arc plate 12, preventing the device from sliding out between the first guide arc plate 11 and the second guide arc plate 12. The first blocking rod 62 connects the second guide arc plate 12 and the third guide arc plate 13, protecting the rotating plate 15. The third blocking rod 64 connects the second guide arc plate 12 and the support rod 3, preventing the device from passing through between the second guide arc plate 12 and the support rod 3, and allowing the first guide arc plate 11, the second guide arc plate 12, and the third guide arc plate 13 to guide the device more smoothly.

[0021] In use, the staggered arrangement of the first guide arc plate 11, the second guide arc plate 12 and the third guide arc plate 13 prevents the slider 7 from falling directly onto the third guide arc plate 13 during its descent, thus avoiding damage to the rotating plate 15 caused by the slider 7.

[0022] Please see Figure 6-7A steel wire rope 16 is fixedly connected to the bottom of the rotating plate 15. The end of the steel wire rope 16 away from the rotating plate 15 passes through the interior of the third guide arc plate 13 and extends to the exterior of the third guide arc plate 13. A displacement plate 18 is fixedly connected to the end of the steel wire rope 16 away from the rotating plate 15. A limiting shaft 17, which is slidably connected to the inside of the limiting support base 59, is fixedly connected to the top of the displacement plate 18. The limiting shaft 17 restricts the movement direction of the displacement plate 18, allowing it to move up and down more smoothly. The steel wire rope 16 drives the rotating plate 15 to rotate, enabling the two rotating plates 15 to position and fix the protective pipe 43 and the drainage pipe of the first water pump 8. Please refer to [link to relevant documentation]. Figure 10 The rotating plate 15 has an internal telescopic groove 21. A clamping positioning plate 23 is slidably connected inside the telescopic groove 21. A first spring 22 is fixedly connected to one end of the clamping positioning plate 23. The end of the first spring 22 away from the clamping positioning plate 23 is fixedly connected to the inner wall of the telescopic groove 21.

[0023] In use, workers slide the first water pump 8 and the filter protective cylinder 9 into the drainage well 2 using ropes. After the slider 7 moves to a certain position, it contacts the first guide arc plate 11. Guided by the first guide arc plate 11 and the second guide arc plate 12, the slider 7 falls onto the third guide arc plate 13. After being guided by the third guide arc plate 13, it falls into the limiting support hole 4 for positioning and support, thus fixing the positions of the first water pump 8 and the filter protective cylinder 9. This allows the first water pump 8 to more stably extract water from the drainage well 2, making the discharge of water from the drainage well 2 smoother. To a certain extent, this reduces the possibility of the first water pump 8 colliding with the interior of the drainage well 2 during its descent, thus preventing damage to the drainage well 2. It also reduces the possibility of the drainage well 2 shaking and causing unstable pumping during pumping. As the protective cylinder 6 descends under the guidance of the third guide arc plate 13, the displacement plate 18 is positioned below the top cover 10, allowing the top cover 10 to move the displacement plate 18 downwards. This causes the displacement plate 18 to move the wire rope 16 downwards, which in turn causes the wire rope 16 to rotate the rotating plate 15 to a horizontal position, thus positioning the drainage pipe of the first water pump 8.

[0024] After the protective pipe 43 falls into the positioning groove 19, the movement of the clamping positioning plate 23 can compress and reset the first spring 22. Thus, after the protective pipe 43 enters the positioning groove 19, the clamping positioning plate 23 under the action of the first spring 22 can clamp the protective pipe 43 to a certain extent, and make the protective pipe 43 more stable in the drainage well 2. This allows the water level detection pressure transmitter inside the protective pipe 43 to detect data more smoothly and to a certain extent ensure the accuracy of the detection data.

[0025] Example 3, please refer to 8. The anti-clogging cleaning component includes a rotating rod 45. The surface of the rotating rod 45 is rotatably connected to the inside of the filter protective cylinder 9. An impeller 44 is fixedly connected to the top of the rotating rod 45. The impeller 44 is located inside the filter protective cylinder 9. When the first water pump 8 draws water from the drainage well 2, the water flow can drive the impeller 44 to rotate due to the restriction of the first water pump 8 and the filter protective cylinder 9. The impeller 44 then drives the rotating rod 45 to rotate. A support transmission rod 46 is fixedly connected to the bottom of the rotating rod 45. The support transmission rod 46 is slidably connected to the blocking sliding groove 65. The support transmission rod 46 can slide out from its interior. The support transmission rod 46 is located at the bottom of the filter protective cylinder 9. Two symmetrical cleaning rods 47 are fixedly connected to the top of the support transmission rod 46. Brushes 5 are provided on both the cleaning rods 47 and the support transmission rod 46. Through the cooperation of the support transmission rod 46 and the slider 7, the protective cylinder 6 and the first water pump 8 can move more smoothly and vertically downward.

[0026] During use, due to the limitations imposed by the first water pump 8 and the filter protection cylinder 9, the water flow drives the impeller 44 to rotate, which in turn drives the rotating rod 45 to rotate. The rotating rod 45 then drives the support transmission rod 46 and the cleaning rod 47 to rotate, allowing the brush 5 to clean the outer surface of the filter protection cylinder 9. This reduces the amount of impurities that adhere to the filter protection cylinder 9 for extended periods, preventing clogging of the mesh and a decrease in the speed at which water flows into the filter protection cylinder 9. Consequently, the first water pump 8 can extract water more smoothly, while also providing better protection and extending its service life.

[0027] Example 4, please refer to Figure 3 , Figure 9-11 Please see. Figure 3 The closed positioning and stabilizing component includes two collection frames 27. The surfaces of the two collection frames 27 are slidably connected to the interior of the drainage well 2. The two collection frames 27 are rotatably connected to each other. The two collection frames 27 are provided with the same structure. A guide plate 28 is fixedly connected to the lower surface of the interior of the collection frame 27. A blocking block 67 is fixedly connected between the collection frame 27 and the guide plate 28. A mounting positioning rod 25 is fixedly connected to the top of the supporting arc plate 24. An assembly groove 26 is opened inside the mounting positioning rod 25.

[0028] In use, the collection frame 27, the blocking block 67 and the guide plate 28 form a chamber that can store rainwater and soil falling from the external environment and reduce the occurrence of rainwater and soil falling into the drainage well 2 when the device is removed. The top of the two guide plates 28 are fixedly connected to the closing positioning plate 29. The closing of the two closing positioning plates 29 can reposition and stabilize the drainage pipe and the protective pipe 43, so that the device can operate more smoothly.

[0029] Please see Figure 9-11 The bottom of the collection frame 27 has an installation groove 48. The surface of the mounting positioning rod 25 is inserted into the interior of the installation groove 48, and the mounting positioning rod 25 can slide into and out of the interior of the installation groove 48. The inside of the collection frame 27 has a power transmission groove 66. An assembly frame 49 extending to the outside of the collection frame 27 is slidably connected inside the power transmission groove 66. The side of the assembly frame 49 near the assembly groove 26 is inserted into the interior of the assembly groove 26. The assembly frame 49 can slide into and out of the interior of the assembly groove 26, and realize the fixing and unfixing of the position of the collection frame 27 and the support arc plate 24. A second spring 30 is fixedly connected to the inner wall of the power transmission groove 66. One end of the second spring 30 is fixedly connected to the surface of the assembly frame 49. The movement of the assembly frame 49 can compress and reset the second spring 30. At the same time, the force of the second spring 30 allows the assembly frame 49 to slide more stably into the assembly groove 26. The internal structure of the assembly frame 49 is designed to ensure stable mounting of the device. A transmission plate 31 is fixedly connected to one side of the assembly frame 49. A movable groove 33 is provided on the top of the transmission plate 31. A power groove 36 is provided inside the closed positioning plate 29. A rotating shaft 35 extending to the bottom outer surface of the closed positioning plate 29 is rotatably connected inside the power groove 36. A gear 37 is fixedly connected to the surface of the rotating shaft 35 inside the power groove 36. A rack 38 is slidably connected inside the power groove 36. A tooth is provided on one side of the rack 38. The rack 38 is meshed with the surface of the gear 37 through the tooth. The movement of the rack 38 can drive the gear 37 and the rotating shaft 35 to rotate. A rotating transmission plate 34 is fixedly connected to the bottom of the rotating shaft 35. A transmission column 32 is fixedly connected to the bottom of the rotating transmission plate 34. The transmission column 32 is located on the side away from the rotating shaft 35. The surface of the transmission column 32 is movably connected to the interior of the movable groove 33.

[0030] In use, the rotating shaft 35 drives the rotating transmission plate 34 to rotate, which enables the transmission column 32 to drive the transmission plate 31 and the assembly frame 49 to move through the movable groove 33, and allows the assembly frame 49 to slide out of the interior of the assembly groove 26.

[0031] Please see Figure 9-13The top of the closed positioning plate 29 is provided with a movable adjustment groove 42 that communicates with the inside of the power groove 36. The movable adjustment groove 42 is slidably connected to a movable frame 39 that is fixedly connected to the surface of the rack 38. The surface of the movable frame 39 is slidably connected to the inside of the power groove 36. A third spring 40 is fixedly connected to one side of the movable frame 39. The end of the third spring 40 away from the movable frame 39 is fixedly connected to the inner wall of the power groove 36. The third spring 40 can be compressed and reset by moving the movable frame 39. A pulling frame 41 is fixedly connected to the top of the movable frame 39.

[0032] During use, the pull frame 41 can block the movable adjustment groove 42. A baffle 68 is provided on one side of the pull frame 41 on a closed positioning plate 29. After the two closed positioning plates 29 are closed, the pull frame 41 with the baffle is pulled under the obstruction of the baffle, so that the two pull frames 41 on the two closed positioning plates 29 can move synchronously and realize that the two assembly frames 49 of the device slide out of the interior of the assembly groove 26 at the same time, making it easier to fix and release the collection frame 27 and the support arc plate 24.

[0033] In use, the operator rotates the two collection frames 27 and positions the closed positioning plate 29 around the protective pipe 43 and the drainage pipe. Then, the two collection frames 27 slide into the drainage well 2. Under the constraint of the drainage well 2, the two collection frames 27 close. Pulling the movable adjustment groove 42 with the baffle 68 allows the two pulling frames 41 on the closed positioning plate 29 to move synchronously. The pulling frames 41 drive the movable frame 39 and the rack 38 to move, compressing the third spring 40. The second spring 30 drives the gear 37 and the rotating shaft 35 to rotate, causing the rotating shaft 35 to drive the rotating transmission plate 34 and the transmission column 32 to rotate. The transmission column 32, through the movable groove 33, drives the transmission plate 31 and the assembly frame 49 to move, allowing the two assembly frames 49 to slide out of the assembly groove 26 simultaneously, and causing the second spring 30 to... The collection frame 27 is compressed and then pressed down further, causing the installation positioning rod 25 to slide into the installation groove 48. After that, the operator releases the hand that pulls the pull frame 41, and the third spring 40 and the second spring 30 return to their original positions, allowing the assembly frame 49 to slide into the assembly groove 26. This fixes the positions of the collection frame 27 and the support arc plate 24, making the installation and fixing of the device more convenient. When the device needs to be disassembled, the operator pulls the pull frame 41 again to disassemble the assembly frame 49 from the assembly groove 26, enabling the device to be disassembled. This allows the device to protect the drainage well 2 more smoothly and reduces the direct inflow of soil and rainwater from the external environment into the drainage well 2, preventing blockages and ensuring that the first water pump 8 can effectively pump water from the drainage well 2. This makes it easier for the operator to use the device.

[0034] Working Principle: A zoned and graded intelligent dewatering system and construction method for deep foundation pits in the Yangtze River floodplain. During operation, workers use ropes to slide the first water pump 8 and the filter protection cylinder 9 into the dewatering well 2. After the slider 7 moves to a certain position, it contacts the first guide arc plate 11. Guided by the first and second guide arc plates 11 and 12, the slider 7 falls onto the third guide arc plate 13. Guided by the third guide arc plate 13, it then falls into the limiting support hole 4 for positioning and support, thus fixing the positions of the first water pump 8 and the filter protection cylinder 9. This allows the first water pump 8 to more stably extract water from the dewatering well 2, ensuring a smooth flow of water within the well. The discharge is smoother. During the process of the protective cylinder 6 descending under the guidance of the third guide arc plate 13, the top cover 10 can drive the displacement plate 18 to move downward, so that the wire rope 16 drives the rotating plate 15 to rotate to a horizontal state, so that the rotating plate 15 can position the drainage pipe of the first water pump 8. When the protective pipe 43 falls into the interior of the positioning groove 19, the movement of the pressing positioning plate 23 can compress and reset the first spring 22, so that after the protective pipe 43 enters the interior of the positioning groove 19, the pressing positioning plate 23 under the action of the first spring 22 can press the protective pipe 43 to a certain extent, and make the protective pipe 43 more stable in the interior of the drainage well 2. When using the collection frame 27, the operator rotates the two collection frames 27 and positions the closed positioning plate 29 on the protective pipe 43 and the drainage pipe. Then, the two collection frames 27 are slid into the drainage well 2. Under the restriction of the drainage well 2, the two collection frames 27 are closed. Pulling the movable adjustment groove 42 with the baffle 68 allows the two pulling frames 41 on the two closed positioning plates 29 to move synchronously. This allows the two assembly frames 49 of the device to slide out of the assembly groove 26 at the same time, and compresses the second spring 30. Then, the collection frame 27 is pressed down further, and the installation positioning rod 25 slides into the installation groove 48. The operator then releases the hand that pulls the pulling frame 41, and the third spring 40 and the second spring 30 return to their original positions, allowing the assembly frame 49 to slide into the assembly groove 26. This fixes the positions of the collection frame 27 and the supporting arc plate 24. When the device needs to be disassembled, the operator pulls the pulling frame 41 again to disassemble the assembly frame 49 from the assembly groove 26, thus enabling the device to be disassembled more smoothly and protecting the drainage well 2. When the water is being pumped, the staff starts the first water pump 8 through an external control device. The first water pump 8 pumps the water inside the drainage well 2 and causes the impeller 44 and the rotating rod 45 to rotate. The rotating rod 45 drives the support transmission rod 46 and the cleaning rod 47 to rotate, which enables the brush 5 to clean the outer surface of the filter protection cylinder 9 and reduces the amount of impurities that adhere to the filter protection cylinder 9 for a long time, thus preventing the mesh of the filter protection cylinder 9 from becoming clogged and the water flow speed inside the filter protection cylinder 9 from decreasing.

[0035] Please see Figure 1 A construction method for a zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain includes the following specific operational steps: S1. Set up zoned dewatering units: After the foundation pit is excavated, based on the isolation status of the foundation pit retaining structure against confined water, combined with the stratum lithology, aquifer distribution and sensitivity of the surrounding environment, the foundation pit is divided into three types of areas: areas with completely isolated confined water, areas with partially isolated confined water and areas with unisolated confined water. Two dewatering wells are configured to completely isolate the confined water area. Each well has an effective dewatering area of ​​250m² / well. The well pipe is made of steel pipe with a diameter of 273mm and a wall thickness of 6mm. Filter pipes are installed above the excavation surface. Filter holes are opened on the filter pipes. Medium and coarse sand filter material is poured into the whole hole. The drainage well 2 positions and supports the slider 7 through the limiting support hole 4, and fixes the positions of the first water pump 8 and the filter protection cylinder 9, so that the first water pump 8 can more stably draw water from the inside of the drainage well 2. The anti-clogging cleaning component cleans the outer surface of the filter protection cylinder 9, which to a certain extent reduces the long-term adhesion of impurities to the filter protection cylinder 9 and prevents the mesh of the filter protection cylinder 9 from becoming clogged. The collection frame 27 and the guide plate 28 form a chamber that can store rainwater and soil falling from the external environment, preventing soil from entering the interior of the drainage well 2 and causing pollution and blockage. In the partially isolated pressurized water area, a combination of dewatering well 2 and depressurization well 50 is configured. Dewatering well 2 uses a sand-free concrete pipe with an inner diameter of 300mm, and the filter pipe of depressurization well 50 is 12m shallower than the bottom elevation of the retaining structure. The unisolated confined water area adopts a three-in-one configuration of pressure reduction well 50, drainage well 2 and backup well outside the pit. Pressure reduction well 50 adopts a combination structure of full-hole filter material and solid steel pipe. The spacing of the backup well outside the pit is 1520m, which also serves as water level observation well 51. S2, Intelligent Monitoring Unit: Drilling and reinjection wells, and setting up layered water level monitoring module, deformation monitoring module, operation status monitoring module and data transmission module in observation well 51; Groundwater extracted through recharge wells is injected back into the foundation soil. Water seeps into the soil around the well point, forming an inverted drop funnel opposite to that of the dewatering well point. This ensures that the influence radius of the dewatering well point does not exceed the range of the recharge well point. The recharge well point acts as a water-proof curtain, preventing groundwater loss from buildings outside the recharge well point. This keeps the groundwater level essentially unchanged and the soil pressure in its original equilibrium state, thus effectively preventing the dewatering well point from affecting surrounding buildings. The stratified water level monitoring module is equipped with high-precision water level sensors in the unconfined aquifer, the upper confined aquifer, and the lower confined aquifer, with a monitoring accuracy of ±0.01m, for monitoring water levels. The deformation monitoring module includes a ground settlement monitor (30m spacing in sensitive areas and 50m spacing in non-sensitive areas), a pipeline displacement monitor, and a retaining structure displacement sensor, used to monitor ground settlement; the operation status monitoring module installs flow sensors and pressure sensors in each dewatering well and recharge well to monitor the water level and drainage flow in the well. The data transmission module uses LoRa wireless transmission technology with a transmission delay of ≤5s, and uploads the data collected by the sensor to the control center database in real time. S3, Dynamic Control Unit: Composed of a data processing module, a numerical model module, a parameter optimization module, and an execution module, it realizes automatic adjustment of precipitation parameters; The data processing module uses the Kalman filter algorithm to reduce noise in the monitoring data and remove environmental interference signals; The numerical model module constructs a three-dimensional groundwater flow model based on MODFLOW and establishes a settlement prediction model by combining Terzaghi's one-dimensional consolidation theory. The model parameters are calibrated through field pumping tests. The model input parameters include the permeability coefficient of unconfined aquifer Kxx=Kyy=0.01m / d, confined aquifer (silty sand) Kxx=Kyy=25m / d, Kzz=12m / d, confined aquifer (pebbles and gravel) Kxx=Kyy=40m / d, Kzz=30m / d, and the initial hydraulic head elevation +7.0m. The parameter optimization module outputs the optimal precipitation flow rate, water level control threshold, and recharge volume parameters in real time based on the excavation progress, water level changes, and settlement data. The execution module automatically adjusts the precipitation parameters through the first water pump 8, the second water pump 52, the third water pump 56, and the fourth water pump 57 (adjustment range 0-1200m³ / d) and electric valves. S4 Emergency Support Unit: Includes a dual power supply module, a reinjection compensation module, a piping and leak plugging module, and an intelligent early warning module; the dual power supply module automatically switches between the main power supply and the backup power supply to ensure continuous operation during rainfall. Recharge wells are arranged in sensitive areas at intervals of 1015m. The recharge volume of a single well is 1 / 3 of the output of the corresponding dewatering well. The depth of the recharge well is 2430m. The well pipe is made of steel pipe with a diameter of 273mm. The filter pipe is located in the unconfined layer and the upper confined aquifer. The filter material is placed 2m above the top of the filter pipe. The upper part is backfilled with high-quality clay balls to stop water. The piping plugging module is equipped with dual-fast cement, polyurethane grouting components and high-pressure grouting pump, and comes with a customized plugging tool kit; the intelligent early warning module presets multiple early warning thresholds such as abnormal water level, excessive settlement, and sudden flow changes, and automatically pushes instructions to the emergency response system when an early warning is triggered; The structural parameters of the pressure reduction well 50 are as follows: well depth 2138m, mud hole diameter 600mm, filter pipe adopts round hole steel filter pipe with filter holes on the filter pipe, wrapped with 80 mesh nylon filter screen, 1m sedimentation pipe at the bottom, medium and coarse sand filter material is poured into the whole hole, and coarse filter material is poured into the 23m section above the excavation face to enhance the drainage effect. The two drainage wells are divided into steel pipe drainage wells and sand-free concrete pipe drainage wells. Both adopt a full-hole filter pipe design, wrapped with an 80-mesh nylon filter screen 1, and filter material is poured into the full hole. The sand-free concrete pipe drainage well has a single section length of 1m, which is convenient for later dismantling. The sensor arrangement of the intelligent monitoring unit meets the following requirements: one stratified water level sensor is deployed every 50m in the unconfined aquifer and one sensor is deployed every 30m in the confined aquifer. Ground settlement monitoring devices are densified to a spacing of 20m around sensitive buildings; pipeline displacement monitoring devices are deployed every 15m along the pipeline route, with additional monitoring points at corners. All sensors are waterproof and corrosion resistant, with a protection rating of ≥IP68, and are suitable for long-term operation in damp underground environments. The numerical model module of the dynamic control unit supports real-time iterative updates. Every two hours, the model parameters are calibrated based on the latest monitoring data. The optimal dewatering scheme is output in stages according to the excavation progress of the foundation pit. The pre-dewatering mode is started 20 days before excavation, and one of the 20% dewatering wells is put into operation. During the excavation process, the dynamic tracking mode is started, and the water level is controlled 1m below the excavation surface. During the bottom slab construction stage, the anti-buoyancy dewatering mode is started, and 50% of the pressure reduction wells are kept in operation as needed. The reinjection compensation module is equipped with a water purification device, and the reinjection water source is clean water after rainwater treatment. The piping plugging module includes a graded treatment plan. For minor piping, double fast cement is used for sealing; for moderate piping, double fast cement + polyurethane grouting is used; and for severe piping, a comprehensive treatment plan of pressure reduction + combined grouting is initiated from the backup well outside the pit. S5. Exploration and Modeling Stage: Conduct detailed geotechnical engineering investigation to determine the stratigraphic distribution, aquifer parameters, and surrounding environmental conditions. Use a "one pump, two observations" pumping test to verify hydrogeological parameters and obtain the average permeability coefficient K=18.66m / d. Based on the investigation results, construct a three-dimensional hydrogeological conceptual model and a settlement prediction model. Use a hexahedral mesh and vertically divide it into seven layers to clarify the safe water level threshold and precipitation requirements for each zone. S6. The well-drilling phase is divided into zones and stages: A positive circulation rotary drilling mud-wall protection process is adopted, strictly controlling the borehole deviation to ≤1.0m and the well depth deviation to ≤±50cm; in areas completely isolated from confined water, dewatering well 2 is constructed first. After completion, the well is flushed with a submersible pump until the sand content of the effluent is ≤1 / 100000 (volume ratio), and a sensitivity test is performed; in areas with partially isolated and unisolated confined water, depressurization well 50 and dewatering well 2 are constructed simultaneously. The depressurization well 50 is constructed with a well inclination controlled to ≤1°, and the filter pipe installation verticality deviation is ≤0.5°; the backup well outside the pit is constructed simultaneously with the main dewatering well to ensure emergency activation efficiency. S7. Intelligent Trial Operation Phase: Install all monitoring sensors and control equipment, conduct a 24-hour group well pumping test, verify the accuracy of the numerical model, and debug the stability of sensor data transmission and the response speed of the actuator; set the safe water level threshold (confined water level is 1m below the excavation surface), settlement warning value (sensitive area ≤16mm, general area ≤30mm) and flow anomaly threshold (single well flow fluctuation ±20%) for each zone. S8. Dynamic Dewatering Stage: Following the principles of "dewatering on demand, zoned control, and synchronous monitoring," dewatering wells in corresponding areas are opened according to the progress of foundation pit excavation. Monitoring data is received in real time through the dynamic control unit, and the numerical model outputs the optimal dewatering parameters every two hours. The execution module automatically adjusts the flow rate of the first pump 8, the second pump 52, the third pump 56, and the fourth pump 57, as well as the opening of the electric valves. The reinjection compensation module is activated synchronously in sensitive areas to control ground settlement to ≤16mm. Sediment in the wells is cleaned regularly, and a comprehensive equipment overhaul is carried out monthly. S9. Emergency Response Phase: When the water level is detected to be 5% higher than the safety threshold, the number of dewatering wells opened or the water pump flow rate will be automatically increased; when the settlement reaches 80% of the warning value, the precipitation intensity in the corresponding area will be reduced and the recharge volume will be increased; when piping occurs, the backup well outside the pit will be activated immediately to reduce pressure, and the seepage outlet will be sealed with double-fast cement simultaneously. If necessary, polyurethane will be injected to seal the leakage channel; in the event of a power outage, the dual power supply module will automatically switch to the backup power supply, with a switching time of ≤10 minutes. S10, Well Sealing and Protection Phase: Well sealing will be carried out in three phases to ensure the safety of the foundation pit structure and prevent groundwater pollution; S10-1: Before the construction of the base plate, the drainage well 2 and some observation and backup wells were sealed by "clay backfilling + concrete pouring"; S10-2: After the base plate is completed and reaches the design strength, leave part of the depressurization well 50 for pumping water and anti-buoyancy, and the remaining depressurization well 50 adopt the process of "grouting + concrete pouring + steel plate welding". S10-3: After the foundation pit meets the anti-buoyancy requirements, the remaining 50 pressure-reducing wells will be sealed. The specific steps are as follows: S10-3-1 Weld an 800mm diameter, 10mm thick waterstop steel plate to the middle of the concrete base slab; S10-3-2. A grouting pipe is lowered into the well to the bottom of the well. S10-3-3 Add sunflower seed chips to a depth of 2m below the bottom plate; S10-3-4 High-pressure grouting until the water level stabilizes; S10-3-5 Pour concrete to 10cm below the bottom slab; S10-3-6 Remove excess well casing, weld the casing opening and apply mortar to level it.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain, comprising a dewatering well (2), a depressurization well (50), an observation well (51), and a recharge well (58), wherein the outer surface of the dewatering well (2) is provided with a filter screen (1), and filter holes are formed on the surface of the dewatering well (2) above the excavation surface of the foundation pit, characterized in that: The inner surface of the drainage well (2) is fixedly connected to two symmetrical support rods (3). The top of the support rods (3) is provided with a limiting support hole (4). The inside of the support rods (3) is provided with a blocking sliding groove (65) that communicates with the inside of the limiting support hole (4). The inside of each of the two limiting support holes (4) is slidably connected to a slider (7). A top cover (10) is fixedly connected between the two sliders (7). A protective cylinder (6) is fixedly connected to the bottom of the top cover (10). A first water pump (8) is fixedly connected inside the protective cylinder (6). A drain pipe extending to the outside of the top cover (10) is fixedly connected to the drain end of the first water pump (8). The bottom of the protective cylinder (6) is fixedly connected to the filter protective cylinder (9), and the filter protective cylinder (9) has a mesh hole. The filter protective cylinder (9) is equipped with an anti-clogging cleaning component for cleaning the filter protective cylinder (9). The drain well (2) is equipped with a protective pipe (43). The drain well (2) is equipped with a stable positioning component for positioning the protective pipe (43). The drain well (2) is fixedly connected to two supporting arc plates (24). The drain well (2) is equipped with a closed positioning stable component for positioning and fixing the protective pipe (43) and the drain pipe of the first water pump (8).

2. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 1, characterized in that: Both the pressure-reducing well (50) and the observation well (51) have a filter screen (1) installed on their outer surfaces. The pressure-reducing well (50) has a second water pump (52) installed inside. The pressure-reducing well (50) has a fourth water level sensor (60) installed inside. The observation well (51) has a third water pump (56) installed inside. The observation well (51) has a first water level sensor (53), a second water level sensor (54), and a third water level sensor (55) installed inside. The first water level sensor (53), the second water level sensor (54), and the third water level sensor (55) are installed in descending order of height. The recharge well (58) has a filter screen (1) installed inside. There is a fourth water pump (57), one end of the first water level sensor (53) is electrically connected to the controller (61), one end of the second water level sensor (54), the third water level sensor (55) and the fourth water level sensor (60) are all electrically connected to the controller (61), a flow sensor is installed on the surface of the drain pipe outside the drainage well (2), and a flow sensor is also installed on the drain pipe of the second water pump (52), the third water pump (56) and the fourth water pump (57), and the first pump body (8), the second water pump (52), the third water pump (56) and the fourth water pump (57) are all electrically connected to the controller (61).

3. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 1, characterized in that: The controller (61) is equipped with a control center module. The signal output terminal of the control center module is connected to the intelligent detection unit, the dynamic control unit and the emergency support unit. The intelligent detection unit includes a stratified water level monitoring module, a deformation monitoring module, an operation status monitoring module and a data transmission module. The signal input terminal of the stratified water level monitoring module is connected to the signal output terminals of the first water level sensor (53), the second water level sensor (54), the third water level sensor (55) and the fourth water level sensor (60). The signal input terminal of the operation status monitoring module is connected to the signal output terminal of the flow sensor. The dynamic control unit includes a data processing module, a numerical model module, a parameter optimization module and an execution module. The emergency support unit includes a dual power supply module, a reinjection compensation module, a piping and leak plugging module and an intelligent early warning module.

4. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 1, characterized in that: The stabilizing and positioning assembly includes a first guide arc plate (11), a second guide arc plate (12), and a third guide arc plate (13). The surfaces of the first guide arc plate (11), the second guide arc plate (12), and the third guide arc plate (13) are all fixedly connected to the inner surface of the drainage well (2). The first guide arc plate (11), the second guide arc plate (12), and the third guide arc plate (13) are arranged sequentially from top to bottom. The downward-sloping end of the third guide arc plate (13) is fixedly connected to the surface of the support rod (3). The drainage well (2) is internally fixedly connected to four support seats (14). The four support seats (14) are arranged in groups of two. The two support seats (14) in a group are connected by torque. A rotating plate (15) is rotatably connected to a spring and a shaft. The rotating plate (15) is located between the second guide arc plate (12) and the third guide arc plate (13). A positioning groove (19) is provided on one side of the rotating plate (15). A guide limiting plate (20) is fixedly connected to the top of the rotating plate (15). A guide groove for guiding the protective pipe (43) is provided on the guide limiting plate (20). A wire rope (16) is fixedly connected to the bottom of the rotating plate (15). A limiting support seat (59) is fixedly connected to the inner wall of the drainage well (2). The end of the wire rope (16) away from the rotating plate (15) passes through the interior of the limiting support seat (59) and extends to the exterior of the limiting support seat (59).

5. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 4, characterized in that: A second blocking rod (63) is fixedly connected between the first guide arc plate (11) and the second guide arc plate (12). A (62) is fixedly connected between the second guide arc plate (12) and the third guide arc plate (13). A third blocking rod (64) is fixedly connected to the top of the support rod (3) and fixedly connected to the bottom of the second guide arc plate (12). A displacement plate (18) is fixedly connected to the end of the wire rope (16) away from the rotating plate (15). A limiting shaft (17) is fixedly connected to the top of the displacement plate (18) and slidably connected to the inside of the limiting support seat (59). A telescopic groove (21) is opened inside the rotating plate (15). A top-tightening positioning plate (23) is slidably connected inside the telescopic groove (21). A first spring (22) is fixedly connected to one end of the top-tightening positioning plate (23). The end of the first spring (22) away from the top-tightening positioning plate (23) is fixedly connected to the inner wall of the telescopic groove (21).

6. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 1, characterized in that: The anti-clogging cleaning assembly includes a rotating rod (45), the surface of which is rotatably connected to the inside of the filter protection cylinder (9). An impeller (44) is fixedly connected to the top of the rotating rod (45), and the impeller (44) is located inside the filter protection cylinder (9). A support transmission rod (46) is fixedly connected to the bottom of the rotating rod (45). The support transmission rod (46) is slidably connected to the blocking sliding groove (65). The support transmission rod (46) is located at the bottom of the filter protection cylinder (9). Two symmetrical cleaning rods (47) are fixedly connected to the top of the support transmission rod (46). Brushes (5) are provided on both the cleaning rods (47) and the support transmission rod (46).

7. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 1, characterized in that: The closed positioning and stabilizing assembly includes two collection frames (27). The surfaces of the two collection frames (27) are slidably connected to the interior of the drainage well (2). The two collection frames (27) are rotatably connected to each other. A guide plate (28) is fixedly connected to the lower surface of the interior of the collection frame (27). The collection frame (27) and the guide plate (28) form a chamber. A closed positioning plate (29) is fixedly connected to the top of each of the two guide plates (28). A mounting positioning rod (25) is fixedly connected to the top of the supporting arc plate (24). An assembly groove (26) is opened inside the mounting positioning rod (25). An installation groove (48) is opened at the bottom of the collection frame (27). The surface of the positioning rod (25) is inserted into the interior of the mounting groove (48). The inside of the collection frame (27) is provided with a power transmission groove (66). The inside of the power transmission groove (66) is slidably connected to an assembly frame (49) extending to the outside of the collection frame (27). The side of the assembly frame (49) near the assembly groove (26) is inserted into the interior of the assembly groove (26). The inner wall of the power transmission groove (66) is fixedly connected with a second spring (30). One end of the second spring (30) is fixedly connected to the surface of the assembly frame (49). A transmission plate (31) is fixedly connected to one side of the assembly frame (49). The top of the transmission plate (31) is provided with a movable groove (33).

8. The intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 7, characterized in that: The closed positioning plate (29) has a power groove (36) inside. The power groove (36) is rotatably connected to a rotating shaft (35) extending to the bottom outer surface of the closed positioning plate (29). A gear (37) is fixedly connected to the surface of the rotating shaft (35) inside the power groove (36). A rack (38) is slidably connected inside the power groove (36). One side of the rack (38) is provided with teeth. The rack (38) meshes with the surface of the gear (37) through the teeth. A rotating transmission plate (34) is fixedly connected to the bottom of the rotating shaft (35). A transmission column (32) is fixedly connected to the bottom of the rotating transmission plate (34). The transmission column (32) is located on the side away from the rotating shaft (35). The surface of the transmission column (32) is movably connected to the inside of the movable groove (33).

9. A zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain area according to claim 8, characterized in that: The top of the closed positioning plate (29) is provided with a movable adjustment groove (42) that communicates with the inside of the power groove (36). The movable adjustment groove (42) is slidably connected to a movable frame (39) that is fixedly connected to the surface of the rack (38). The surface of the movable frame (39) is slidably connected to the inside of the power groove (36). A third spring (40) is fixedly connected to one side of the movable frame (39). The end of the third spring (40) away from the movable frame (39) is fixedly connected to the inner wall of the power groove (36). A pulling frame (41) is fixedly connected to the top of the movable frame (39).

10. A construction method for a zoned and graded intelligent dewatering system for deep foundation pits in the Yangtze River floodplain, as described in claims 1-9, includes the following specific operational steps: S1. Set up zoned dewatering units: After the foundation pit is excavated, based on the isolation status of the foundation pit retaining structure against confined water, combined with the stratum lithology, aquifer distribution and sensitivity of the surrounding environment, the foundation pit is divided into three types of areas: areas with completely isolated confined water, areas with partially isolated confined water and areas with unisolated confined water. In areas where the confined water is completely isolated, a drainage well (2) is configured. In areas where the confined water is partially isolated, a combination of a drainage well (2) and a pressure-reducing well (50) is configured. In areas where the confined water is not isolated, a three-in-one configuration of a pressure-reducing well (50), a drainage well (2), and an external backup well is adopted. The external backup well also serves as a water level observation well (51). The dewatering well (2) is divided into steel pipe dewatering well and sand-free concrete pipe dewatering well. Both adopt a full-hole filter pipe design and are wrapped with an 80-mesh nylon filter screen (1). The dewatering well (2) uses the limiting support hole (4) to position and support the slider (7) and fix the position of the first water pump (8) and the filter protection cylinder (9), so that the first water pump (8) can more stably extract water from the inside of the dewatering well (2). The anti-clogging cleaning component cleans the outer surface of the filter protection cylinder (9), which reduces the long-term adhesion of impurities on the filter protection cylinder (9) to a certain extent, and prevents the mesh of the filter protection cylinder (9) from becoming clogged. A chamber is formed by the collection frame (27) and the guide plate (28), which can store rainwater and soil falling from the external environment and prevent soil from entering the interior of the dewatering well (2) and causing pollution and blockage. S2, Intelligent monitoring unit: Drilling and recharge wells, and setting up layered water level monitoring module, deformation monitoring module, operation status monitoring module and data transmission module in observation well (51); The stratified water level monitoring module deploys high-precision water level sensors in the unconfined aquifer, upper confined aquifer, and lower confined aquifer to monitor water levels. The deformation monitoring module includes a ground settlement monitor, pipeline displacement monitor, and retaining structure displacement sensor to monitor ground settlement. The operational status monitoring module installs flow and pressure sensors in each dewatering well and recharge well to monitor water levels and drainage flow rates. The data transmission module uses LoRa wireless transmission technology to upload the data collected by the sensors to the control center database in real time. S3, Dynamic Control Unit: Composed of a data processing module, a numerical model module, a parameter optimization module, and an execution module, it realizes automatic adjustment of precipitation parameters; The data processing module uses the Kalman filter algorithm to reduce noise in the monitoring data and remove environmental interference signals; The numerical model module constructs a three-dimensional groundwater flow model based on MODFLOW and establishes a settlement prediction model by combining Terzaghi's one-dimensional consolidation theory. The model parameters are calibrated through field pumping tests. The model input parameters include the permeability coefficient of unconfined aquifer Kxx=Kyy=0.01m / d, confined aquifer (silty sand) Kxx=Kyy=25m / d, Kzz=12m / d, confined aquifer (pebbles and gravel) Kxx=Kyy=40m / d, Kzz=30m / d, and the initial hydraulic head elevation +7.0m. The parameter optimization module outputs the optimal precipitation flow rate, water level control threshold and recharge amount parameters in real time based on the excavation progress, water level changes and settlement data; the execution module realizes automatic adjustment of precipitation parameters through the first water pump (8), the second water pump (52), the third water pump (56) and the fourth water pump (57) and electric valves; S4. Emergency Support Unit: Includes dual power supply module, reinjection compensation module, piping plugging module and intelligent early warning module; The dual power supply module adopts automatic switching between the main power supply and the backup power supply to ensure continuous operation of the dewatering system; The numerical model module of the dynamic control unit supports real-time iterative updates, calibrating the model parameters every two hours based on the latest monitoring data, and outputting the optimal dewatering plan in stages according to the excavation progress of the foundation pit. The reinjection compensation module is equipped with a water purification device, and the reinjection water source is clean water after rainwater treatment. The piping plugging module includes a graded treatment plan. For minor piping, double fast cement is used for sealing; for moderate piping, double fast cement + polyurethane grouting is used; and for severe piping, a comprehensive treatment plan of pressure reduction + combined grouting is initiated from the backup well outside the pit. The piping plugging module is equipped with dual-fast cement, polyurethane grouting components and high-pressure grouting pump, and comes with a customized plugging tool kit; the intelligent early warning module presets multiple early warning thresholds such as abnormal water level, excessive settlement, and sudden flow changes, and automatically pushes instructions to the emergency response system when an early warning is triggered; S5. Exploration and Modeling Stage: Conduct detailed geotechnical engineering investigation to determine the stratigraphic distribution, aquifer parameters, and surrounding environmental conditions. Use pumping tests to verify hydrogeological parameters and obtain the average permeability coefficient K=18.66m / d. Based on the investigation results, construct a three-dimensional hydrogeological conceptual model and a settlement prediction model. Use hexahedral meshing and vertical subdivision into seven layers to clarify the safe water level threshold and precipitation requirements for each zone. S6. The well-forming stage of the zoned and graded process: adopt the positive circulation rotary drilling mud wall protection process, strictly control the drilling deviation and well depth deviation; in the area where the confined water is completely isolated, first construct the dewatering well (2), and after the well is completed, use a submersible pump to wash the well until the sand content of the water is produced, and conduct sensitivity testing; in the areas where the confined water is partially isolated and not isolated, construct the depressurization well (50) and the dewatering well (2) simultaneously. The construction of the depressurization well (50) is controlled to have a well inclination ≤1° and a filter pipe installation verticality deviation ≤0.5°; the backup well outside the pit is constructed simultaneously with the main dewatering well to ensure the efficiency of emergency activation; S7. Intelligent trial operation phase: Install all monitoring sensors and control equipment, conduct a 24-hour group well pumping test, verify the accuracy of the numerical model, and debug the stability of sensor data transmission and the response speed of the actuator. Set safe water level thresholds, settlement warning values, and abnormal flow thresholds for each zone; S8. Dynamic Dewatering Stage: Following the principles of on-demand dewatering, zoned regulation, and synchronous monitoring, dewatering wells in the corresponding areas are opened according to the excavation progress of the foundation pit; monitoring data is received in real time through the dynamic regulation unit, and the numerical model outputs the optimal dewatering parameters every two hours. The execution module automatically adjusts the flow rate and electric valve opening of the first pump (8), the second pump (52), the third pump (56), and the fourth pump (57); the reinjection compensation module is opened synchronously in sensitive areas to control the ground settlement; sediment in the wells is cleaned regularly, and a comprehensive equipment overhaul is carried out once a month. S9. Emergency Response Phase: When the water level is detected to be 5% higher than the safety threshold, the number of dewatering wells opened or the water pump flow rate will be automatically increased; when the settlement reaches 80% of the warning value, the precipitation intensity in the corresponding area will be reduced and the recharge volume will be increased; when piping occurs, the backup well outside the pit will be activated immediately to reduce pressure, and the seepage outlet will be sealed with double-fast cement simultaneously. If necessary, polyurethane will be injected to seal the leakage channel; in the event of a power outage, the dual power supply module will automatically switch to the backup power supply, with a switching time of ≤10 minutes. S10, Well Sealing and Protection Phase: Well sealing will be carried out in three phases to ensure the safety of the foundation pit structure and prevent groundwater pollution; S10-1: Before the construction of the base plate, the drainage well (2) and some observation and backup wells were sealed by "clay backfilling + concrete pouring"; S10-2: After the base plate is completed and reaches the design strength, some pressure relief wells (50) are left for pumping water to prevent buoyancy, and the remaining pressure relief wells (50) adopt the process of "grouting + concrete pouring + steel plate welding". S10-3: After the foundation pit meets the anti-buoyancy requirements, the remaining depressurization well (50) is sealed. The specific steps are as follows: S10-3-1 Weld an 800mm diameter, 10mm thick waterstop steel plate to the middle of the concrete base slab; S10-3-2. A grouting pipe is lowered into the well to the bottom of the well. S10-3-3 Add sunflower seed chips to a depth of 2m below the bottom plate; S10-3-4 High-pressure grouting until the water level stabilizes; S10-3-5 Pour concrete to 10cm below the bottom slab; S10-3-6 Remove excess well casing, weld the casing opening and apply mortar to level it.

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