A large-scale foundation pit automatic dewatering device

Abstract

The utility model relates to the technical field of building construction, concretely relates to a large range foundation pit automatic precipitation device, including base, be provided with through -hole on the base, be provided with pivot at the position department of the top of through -hole, this pivot sets up on the fixing frame on the base, be provided with load bearing rope on the pivot, load bearing rope one end is connected with the pivot fixedly, the other end is connected with the water pump fixedly set up below the through -hole, one end of pivot is provided with motor, and the output shaft of motor is connected with pivot fixedly, one side of base is provided with controller, and the controller is connected with motor electric signal, the position department of the top of through -hole is provided with water level detector, and the water level detector is connected with controller electric signal, be provided with filter screen assembly and limit buckle snap -on connection on the limit buckle on the water pump, the utility model discloses the purpose is to solve the technical problem that the water pump position needs manual frequent adjustment to adapt water level change, filter screen disassembly maintenance inconvenience in the large range foundation pit precipitation process.

Description

Technical Field

[0001] This utility model belongs to the field of building construction technology and relates to an automatic dewatering device for large-scale foundation pits. Background Technology

[0002] In the construction industry, foundation pit dewatering is a crucial step in ensuring the safety and quality of deep foundation pit construction. Its core purpose is to lower the groundwater level below the foundation construction surface by extracting groundwater from the pit, thus preventing problems such as slope instability and reduced foundation bearing capacity caused by water accumulation. With the increasing number of large-scale construction projects in cities, the demand for dewatering in large-scale foundation pits (such as those exceeding 1000㎡ in area and 10m in depth) is becoming increasingly prominent. These pits are characterized by complex water level changes, harsh working environments, and long dewatering cycles, placing higher demands on the automation, stability, and ease of maintenance of dewatering devices. Currently, foundation pit dewatering devices mostly rely on water pumps to extract accumulated water, combined with water level detection and control components to achieve dewatering operations. Their technical performance directly affects construction efficiency and cost.

[0003] In large-scale foundation pit dewatering operations, existing equipment suffers from two major problems: First, the pump position requires frequent manual adjustment. Due to the large area of ​​the foundation pit and the significant fluctuations in water level caused by geological conditions and weather (such as rainfall and groundwater recharge), if the pump is fixed at a certain depth, situations such as "pump running dry after water level drops" or "incomplete pumping after water level rises" are likely to occur. Construction personnel need to periodically descend into the foundation pit or manually adjust the pump depth, which is not only labor-intensive but also lacks timeliness, potentially leading to excessive water accumulation in the foundation pit, affecting construction progress, and even causing safety hazards. Second, filter maintenance is inconvenient. The foundation pit water contains a large amount of silt, sand, stones, and other impurities, requiring a filter screen to be installed at the pump suction end to prevent clogging. However, existing filters are mostly fixed with bolts or welded connections. In the muddy and damp foundation pit environment, disassembly, cleaning, or replacement requires tools, making the operation cumbersome and time-consuming. Frequent disassembly and assembly can also easily lead to wear on connecting parts, reducing filtration efficiency and pump lifespan.

[0004] A search revealed existing technical solutions for the automation and filtration maintenance of foundation pit dewatering:

[0005] Patent CN207452925U, titled "Foundation Pit Dewatering Device and System," describes a method for automatically pumping out accumulated water by using a water volume detection device installed in a sump. This device monitors the water content, and a controller starts and stops the water pump based on the detection data, eliminating the need for manual observation and operation. While this solves the problems of pump burn-out and overflow, saving labor costs, it lacks a pump depth adjustment function. The pump is fixed in the sump, making it unable to adapt to dynamic changes in water levels across large foundation pits, resulting in incomplete pumping or low efficiency. Furthermore, it does not address the convenient maintenance design of the filter screen, leaving the filter assembly and disassembly reliant on traditional methods. Utility Model Content

[0006] This utility model provides an automatic dewatering device for large-scale foundation pits, which solves the technical problems of needing to frequently adjust the position of water pumps to adapt to water level changes and the inconvenience of disassembling and maintaining filter screens during the dewatering process of large-scale foundation pits.

[0007] To solve the above problems, the technical solution adopted by the utility model is as follows:

[0008] An automatic dewatering device for large-scale foundation pits includes a base with a through hole. A rotating shaft is positioned above the through hole and mounted on a fixed frame on the base. A load-bearing rope is mounted on the rotating shaft, with one end fixedly connected to the rotating shaft and the other end fixedly connected to a water pump positioned below the through hole. A motor is mounted on one end of the rotating shaft, with its output shaft fixedly connected to the rotating shaft. A controller is mounted on one side of the base and is electrically connected to the motor. A water level detector is positioned directly above the through hole and is electrically connected to the controller. A limit buckle is mounted on the water pump, and a filter assembly is attached to the limit buckle for engagement.

[0009] The principle and advantages of this scheme are as follows:

[0010] The base serves as the supporting foundation for the device, and its through-hole provides a channel for the raising and lowering of the water pump. Driven by a motor, the rotating shaft rotates forward or backward, moving the water pump up and down within the through-hole via a load-bearing rope, thus adjusting the pump's position. A water level detector monitors the water level in the pit in real time and transmits the data to the controller. The controller, acting as the control unit, receives the signal from the water level detector and, based on preset pumping thresholds, initiates pumping when the water level is above a certain height and adjusts the pump position when it is below a certain height. It sends commands to the motor to control the rotation direction of the rotating shaft, thereby precisely adjusting the pump's lowering depth and ensuring the pump is always in the optimal pumping position. Simultaneously, the water pump is connected to a filter screen via limit clips. The filter screen intercepts impurities such as mud, sand, and stones in the pit water, preventing them from entering the pump and causing blockages or damage, thus ensuring stable pump operation. The entire process requires no manual intervention, achieving automated control of the dewatering operation.

[0011] Compared with existing technologies, the existing technology controls the start and stop of the water pump through a water volume detection device, which realizes the automation of water pumping. However, the water pump is fixed in the sump and the depth cannot be adjusted. In large-scale foundation pits, when the water level changes significantly due to factors such as rainfall and groundwater recharge, the water pump will either run dry due to the drop in water level or fail to pump water sufficiently due to the rise in water level. Manual intervention is still required to adjust the position. Moreover, its filtration relies on the fixed filter layer on the side wall and bottom wall of the sump, which is not convenient to maintain and is prone to clogging, affecting the water reduction efficiency.

[0012] This system achieves dynamic adjustment of the water pump based on the water level by linking the water level detector, controller, motor, and shaft. For example, if the water level in the foundation pit drops by 40cm within 10 minutes, the controller can drive the motor to retrieve the load-bearing rope within one minute after receiving data from the water level detector, raising the water pump to the appropriate depth. Existing technologies require manual intervention after detection, which can lead to delays and potentially cause the pump to burn out. This solution ensures the pump operates efficiently at all times, significantly improving pumping efficiency compared to existing technologies.

[0013] The snap-fit ​​connection design replaces the fixed filter layer, allowing a single person to install and remove the filter screen. In actual operation, when the filter screen becomes clogged with silt, causing a decrease in pumping efficiency, there is no need to drain the accumulated water; simply disassemble, clean, and re-fasten the filter screen to restore its use. In contrast, existing technologies require interrupting rainfall and emptying the sump to clean the fixed filter layer, which affects operations.

[0014] Furthermore, one end of the controller is equipped with a storage box for the dewatering pipes. This storage box provides dedicated storage space for the dewatering pipes, preventing wear, tangling, or contamination caused by haphazard placement when not in use, thus extending their service life. It also makes the retrieval and storage of the dewatering pipes more convenient, reducing on-site pipe organization time and improving the efficiency of the device. This results in a more compact structure for the entire dewatering system, facilitating overall movement and management. Especially in the complex environment of large-scale foundation pit construction, it effectively saves space, maintains a clean and orderly work site, and reduces safety hazards caused by cluttered dewatering pipes.

[0015] Furthermore, the load-bearing rope is a steel wire rope, and the outer side of the steel wire rope is wrapped with an anti-corrosion and wear-resistant layer. A rope length meter is installed on the rotating shaft, which is electrically connected to the controller. The controller can calculate the lowering depth of the water pump based on the information fed back by the rope length meter, and automatically adjust the position of the water pump in conjunction with the detection data from the water level detector. By setting the load-bearing rope to a steel wire rope with an outer anti-corrosion and wear-resistant layer, the high strength of the steel wire rope itself can ensure load-bearing safety and withstand the tensile impact in the complex environment of the foundation pit, while the anti-corrosion and wear-resistant layer can effectively isolate moisture, silt, and other corrosive substances. This extends the service life and reduces the hassle of frequent replacements. The rope length meter on the rotating shaft is linked with the controller. The controller accurately calculates the water pump's lowering depth based on the feedback information and automatically adjusts the water pump position in conjunction with the water level detector data. This achieves dynamic and intelligent control of the water pump's depth. When the water level changes, the device can respond quickly without manual intervention, keeping the water pump in the optimal pumping position. This ensures stable dewatering efficiency and avoids problems such as water pump idling or incomplete pumping caused by water level fluctuations. It significantly improves the automation and reliability of large-scale foundation pit dewatering operations.

[0016] Furthermore, the filter assembly is equipped with magnetic adsorption strips at its edges, and corresponding magnetic adsorption areas are provided on the limiting buckles. The filter assembly and the limiting buckles are detachably connected via the magnetic adsorption strips and magnetic adsorption areas. Magnetic connection requires no complicated operations; simply aligning the parts allows for quick adsorption and fixation. Installation and disassembly are more convenient than traditional buckle or bolt connections, significantly reducing the time required for filter cleaning or replacement, making it particularly suitable for the frequent maintenance needs in foundation pit operations. The tightness of the magnetic adsorption ensures a stable connection, preventing the filter from falling off due to vibration during water pump operation, and effectively preventing impurities from entering the water pump through connection gaps, thus ensuring filtration efficiency. In addition, this connection method avoids wear and tear on components due to repeated disassembly and assembly, extending the service life of the filter and limiting buckles, reducing maintenance costs, and making daily operation and maintenance of the device more efficient and worry-free.

[0017] Furthermore, the water level detector includes ultrasonic water level sensors, all of which are electrically connected to the controller. This eliminates the need for direct contact with the water in the pit, preventing the impact of turbid water or debris on the detection elements, reducing the probability of sensor failure, and extending their service life. Simultaneously, the ultrasonic detection has a fast response speed, providing real-time water level data to the controller. Combined with information from the rope length meter, the controller can quickly determine whether the pump position is appropriate and adjust it accordingly, ensuring the pump is always in a high-efficiency pumping state, thus improving the automation accuracy and efficiency of large-scale pit dewatering. In addition, the non-contact detection method allows for flexible installation, eliminating the need to penetrate the water body, reducing installation difficulty and maintenance costs in complex pit environments.

[0018] Furthermore, a support frame is provided at the lower end of the base. This support frame has a telescopic structure. When the foundation pit ground is uneven, the base can be quickly leveled by adjusting the telescopic length of each part of the support frame, ensuring the overall stability of the device and avoiding problems such as water pump shaking and uneven stress on the load-bearing ropes caused by tilting. At the same time, adjusting the overall height of the support frame according to the depth of the foundation pit or operational requirements allows the base to be positioned in a more suitable working position, which not only facilitates the laying and storage of the dewatering pipes, but also provides a more reasonable stress angle for components such as the rotating shaft and motor, reducing mechanical wear. In addition, the telescopic structure allows the support frame to be retracted and folded when not in use, saving transportation and storage space and improving the portability and practicality of the device.

[0019] Furthermore, a filter chamber exists between the filter assembly and the water pump. This filter chamber surrounds the pump's suction end, allowing water to be thoroughly filtered by the filter assembly before entering the pump's suction end. This increases the contact area and filtration path between the water flow and the filter, effectively intercepting more sediment and impurities, preventing them from directly entering the pump and causing blockages or wear, thus extending the pump's lifespan. Secondly, the filter chamber forms a relatively stable water flow buffer space, reducing the impact of water flow impact on the pump's suction efficiency, making the pump's suction smoother and improving the stability of the precipitation operation. In addition, this structure can temporarily store filtered impurities within the filter chamber, reducing the probability of impurities directly adhering to the pump's suction end, facilitating subsequent centralized cleaning and maintenance of the filter screen and filter chamber.

[0020] Furthermore, the filter assembly features a double-layer structure with a first filter and a second filter, separated by a partition cavity. The first filter intercepts larger particles of impurities, preventing them from directly impacting the second filter and reducing the risk of clogging. The second filter further filters finer impurities, improving filtration accuracy and providing double protection against impurities entering the water pump. Simultaneously, the partition cavity provides a buffer space for the water flow, slowing down the flow through the first filter and allowing any remaining fine impurities to settle within the partition cavity under gravity, reducing the filtration pressure on the second filter and extending the overall filtration cycle. Moreover, this structure distributes the load across the single-layer filter; even if one layer is partially damaged, the other layer can still perform its filtering function, improving the device's tolerance and reliability.

[0021] Furthermore, the mesh size of the first filter screen is smaller than that of the second filter screen. The first filter screen can preferentially intercept larger impurities such as stones and twigs, preventing them from clogging or damaging the second filter screen in subsequent stages, thus playing a protective role. After the water flows through the initial filtration chamber, it undergoes fine filtration through the second filter screen, effectively trapping fine mud and particles that were not screened out by the first filter screen, significantly improving the overall filtration effect and further reducing the risk of the water pump being worn or clogged by impurities. This coarse-to-fine filtration logic not only improves filtration efficiency but also rationally distributes the load between the two filter layers, extending the overall service life of the filter screens and reducing maintenance frequency.

[0022] Furthermore, the water pump is equipped with a connection port, which is snap-fitted to the water pump. The snap-fit ​​connection does not require tools and can be quickly installed and removed manually. In the wet and muddy environment of the foundation pit, it can significantly shorten the installation or disassembly time between the connection port and the water pump. The snap-fit ​​connection forms a mechanical self-locking through the preset slot and protrusion structure. When the water pump vibrates or the water flow impacts, it can maintain the stability of the connection and avoid water leakage or detachment caused by loosening, thus ensuring the continuity of the pumping process. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0024] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0025] Figure 3 This is a three-dimensional structural diagram of the present invention.

[0026] Figure 4 This is a schematic diagram of the connection structure between the water pump and the filter screen. Detailed Implementation

[0027] The reference numerals in the accompanying drawings include: base 1, controller 2, storage box 3, mounting bracket 4, motor 5, rotating shaft 6, load-bearing rope 7, support 8, water pump 9, limit buckle 10, filter screen assembly 11, connection port 12, well body 13, water level detector 14, rope length meter 15, magnetic adsorption strip 16, pump body 1 suction end 17, first filter screen 18, second filter screen 19, partition cavity 20, filter cavity 21.

[0028] Example 1 is basically as follows Figure 1-4 As shown, a large-scale automatic dewatering device for foundation pits includes a base 1, which is welded from Q235 steel plate. A 1-meter diameter through-hole is opened in the middle, providing a channel for the lifting and lowering of a water pump 9. Four telescopic supports 8 are welded to the lower end of the base 1. These supports employ a sleeve and pin-fitting structure, and the telescopic range of the supports 8 is 500–800 mm. By adjusting the height of the supports 8, the base 1 can be kept level on uneven ground.

[0029] A U-shaped fixing bracket 4 is bolted to the upper surface of the base 1. A rotating shaft 6, a solid steel shaft with a diameter of 50mm, is mounted inside the fixing bracket 4 via bearings. One end of the rotating shaft 6 is fixedly connected to the output shaft of the motor 5 via a coupling. The motor 5 is a servo motor with a power of 1.5kW. A load-bearing rope 7 is wound around the rotating shaft 6. The load-bearing rope 7 is a steel wire rope with a diameter of 12mm and an outer polyurethane anti-corrosion and wear-resistant layer, with a breaking tensile strength of [missing information]. One end of the load-bearing rope 7 is fixed to the rotating shaft 6, and the other end is connected to the water pump 9 via a shackle. The water pump uses a flow rate... The top lifting ring is connected with a 20m head.

[0030] A rope length meter 15, using an incremental encoder, is installed at the end of the rotating shaft 6 furthest from the motor 5. The rope length meter 15 is electrically connected to the controller 2, which is a PLC controller, model S7-200, capable of detecting the released length of the load-bearing rope 7 in real time, and thus calculating the lowering depth of the water pump 9. The controller 2 is bolted to one side of the base 1. The signal input terminal of the controller 2 is connected to the water level detector 14, which is an ultrasonic water level sensor with a detection range of 0-5m and an accuracy of ±1cm. It is fixed 1m directly above the through hole by a bracket, with its detection direction perpendicular to the water surface of the pit.

[0031] An annular retaining buckle 10 is welded to the outside of the pump body suction end 17 of the water pump 9. A magnetic adsorption area is provided on the retaining buckle 10, and a neodymium iron boron magnet is embedded in the magnetic adsorption area. The filter screen assembly 11 includes a first filter screen 18 and a second filter screen 19. The outer layer is the first filter screen 18, which is made of nylon and has a mesh size of 20. The inner layer is the second filter screen 19, which is made of stainless steel and has a mesh size of 80. A 50mm wide gap cavity 20 is formed between the two filter screens. A magnetic adsorption strip 16 is fixed to the edge of the frame of the filter screen assembly 11. The magnetic adsorption strip is a ferrite magnetic strip, which is attracted and connected to the magnetic adsorption area of ​​the retaining buckle 10 to form a filter cavity 21 that surrounds the pump body suction end 17.

[0032] The outlet of the water pump 9 is connected to the connection port 12 of the downpipe via a snap-fit. The snap-fit ​​is made of engineering plastic and has a self-locking structure. The other end of the downpipe extends to the drainage system outside the foundation pit. A storage box 3 is also bolted to the base 1. This storage box is made of PVC and measures 400×300×200mm. It is used to store unused downpipes.

[0033] The working process and control logic of this embodiment are as follows:

[0034] Device installation: Place the base 1 on a flat surface at the edge of the pit, and adjust the bracket 8 to make the base 1 horizontal; align the ultrasonic water level sensor with the water surface of the pit, and connect the controller 2 to the motor 5 and the rope length meter 15; install the filter screen assembly 11 on the limit buckle 10 of the water pump 9 by magnetic adsorption, and connect the downpipe to the connection port 12 of the water pump 9.

[0035] Automatic precipitation control:

[0036] Initial state: Controller 2 presets a pumping threshold. Pumping starts when the water level is above 1.5m, and pumping is activated when the water level is below 0.5m. Water level detector 14 monitors the water level in real time and transmits the data to controller 2. When the water level... At that time, the controller 2 starts the water pump 9 to pump water, and at the same time obtains the current depth of the water pump 9 through the rope length meter 15.

[0037] When the water level drops: If the water level drops to between 0.5 and 1.5 meters, pump 9 will continue to pump water; if the water level drops further... The controller 2 sends a reverse command to the motor 5, the shaft 6 retracts the load-bearing rope 7, and the water pump 9 is lifted to 30cm below the water level. The depth data fed back by the rope length meter 15 is used for precise control.

[0038] When water levels rise: If rainfall or groundwater replenishment causes water levels to rise... The controller 2 drives the motor 5 to rotate forward, releases the load-bearing rope 7, and lowers the water pump 9 to 50cm below the water level, ensuring that the pump body's suction end 17 is always submerged in water.

[0039] Filter Maintenance: When the pumping efficiency decreases due to impurities clogging the filter assembly 11, the pumping efficiency can be judged by the change in the current of the water pump 9. When the water pump is running normally, its current is within a stable rated range. At this time, the resistance of water flow through the filter assembly is small, and the water pump output power matches the pumping efficiency. As impurities on the filter assembly increase, the resistance of water flow gradually increases. In order to maintain a certain water output, the water pump needs to overcome greater resistance, and the motor load increases accordingly. The current will gradually rise and exceed the rated value. When the clogging becomes more severe and the water flow is seriously obstructed, the actual pumping efficiency of the water pump drops significantly. If the water pump is still working at this time, the motor may experience a sharp increase in current due to overload, or even trigger the protection mechanism, causing a sudden drop in current or power failure. Therefore, by monitoring the fluctuation trend of the water pump current in real time—from a stable rated value to a gradual increase, and then to a sharp change—the degree of clogging of the filter assembly and the decrease in pumping efficiency can be accurately judged, and the controller 2 will issue an alarm signal. Maintenance personnel shut down water pump 9, lift it to the ground using load-bearing rope 7, manually separate the magnetically adsorbed filter screen assembly 11, clean the sediment and impurities in the partition cavity 20 or replace the filter screen, and then reinstall it after cleaning. The whole process requires no tools and can be completed by one person within 5 minutes.

[0040] Abnormal protection: If the rope length meter 15 detects that the length of the load-bearing rope 7 exceeds the preset maximum value, or if the water level detector 14 fails to detect the water surface for 10 consecutive seconds, it may be due to the tilt of the water pump 9. The controller 2 will automatically shut down the motor 5 and the water pump 9 and sound an alarm to prevent equipment damage.

[0041] The above are merely embodiments of this utility model. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, based on the guidance provided in this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A large-scale automatic dewatering device for foundation pits, characterized in that: The device includes a base with a through hole. A rotating shaft is positioned above the through hole and mounted on a bracket on the base. A load-bearing rope is attached to the rotating shaft, with one end fixedly connected to the shaft and the other end fixedly connected to a water pump positioned below the through hole. A motor is mounted at one end of the rotating shaft, with its output shaft fixedly connected to the shaft. A controller is located on one side of the base and is electrically connected to the motor. A water level detector is positioned directly above the through hole and is electrically connected to the controller. A filter assembly is attached to a limit buckle on the water pump and engages with the limit buckle.

2. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, One end of the controller is equipped with a storage box, which is a rainwater pipe storage box.

3. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The load-bearing rope is a steel wire rope, and the outside of the steel wire rope is wrapped with an anti-corrosion and wear-resistant layer; a rope length meter is installed on the rotating shaft, which is electrically connected to the controller. The controller can calculate the lowering depth of the water pump based on the information fed back by the rope length meter, and automatically adjust the position of the water pump in combination with the detection data of the water level detector.

4. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The filter assembly is provided with a magnetic adsorption strip at its edge, and the limiting buckle is provided with a corresponding magnetic adsorption area. The filter assembly and the limiting buckle are detachably connected through the magnetic adsorption strip and the magnetic adsorption area.

5. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The water level detector includes an ultrasonic water level sensor, and the ultrasonic water level sensor is electrically connected to the controller.

6. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The base is provided with a support at its lower end, and the support is a retractable structure.

7. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, There is a filter chamber between the filter assembly and the water pump, which surrounds the water pump's suction end.

8. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The filter assembly has a double-layer structure, including a first filter and a second filter, with a spacer cavity between the first filter and the second filter.

9. A large-scale automatic dewatering device for foundation pits according to claim 8, characterized in that, The mesh count of the first filter screen is smaller than that of the second filter screen.

10. The large-scale automatic dewatering device for foundation pits according to claim 1, characterized in that, The water pump is provided with a connection port, which is snap-fitted to the water pump.

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