Basement dewatering well plugging structure in coastal area and construction method
By employing a dual-sealing structure of sealing plates and micro-expansion concrete layers in the dewatering wells of basements in coastal areas, combined with water pressure monitoring, the problems of difficulty in sealing dewatering wells and leakage risks in basements in coastal areas have been solved, achieving efficient and safe sealing results.
Patent Information
- Application Number
- CN202512041892.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-03
AI Technical Summary
Sealing basement dewatering wells in coastal areas is difficult. Traditional sealing methods are prone to leakage in high humidity and high salinity environments, and there is a lack of effective monitoring methods, resulting in low construction efficiency, significant safety hazards, and inadequate waterproofing.
A dual sealing defense line of sealing plates and micro-expansion concrete layers is adopted. Combined with water pressure monitoring, sealing is achieved by welding sealing plates, steel mesh and micro-expansion concrete layers, and anti-buoyancy plates are welded to the outer wall of the well barrel. Water stop valves are installed for real-time monitoring.
It enables efficient and reliable sealing of basement dewatering wells in coastal areas, reducing the risk of leakage, improving construction safety and durability, and reducing construction cycle and cost.
Smart Images
Figure CN121781615A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dewatering well sealing technology, specifically to the sealing structure and construction method of basement dewatering wells in coastal areas. Background Technology
[0002] In basement construction, wellpoint dewatering is a common technique for lowering the groundwater level and ensuring a dry working environment for foundation pit and structural construction. However, sealing the dewatering wells in the later stages of construction remains a core challenge in the industry, especially in coastal areas. These regions are affected by high groundwater levels, high salinity, and frequent tides, resulting in significantly higher groundwater seepage pressure than inland areas. This necessitates continuous dewatering of the wells until the raft foundation and underground structure are completed before sealing, greatly increasing the difficulty and risk of sealing. Currently, the industry commonly uses single methods such as "steel plate welding sealing" or "concrete filling sealing," lacking targeted combined sealing and monitoring designs, which fails to meet the sealing, durability, and safety requirements of coastal areas.
[0003] Traditional sealing methods have significant drawbacks: poor sealing reliability: traditional steel plate welding sealing relies on gas metal arc welding, which is prone to leakage in coastal high humidity environments due to incomplete welding or material corrosion; while concrete filling sealing uses micro-expansion concrete to reduce shrinkage cracks, long-term water pressure may still cause cracking and form seepage channels.
[0004] Low construction efficiency: The sealing process requires repeated adjustments to the water level in the well and multiple repairs of defects, which significantly prolongs the cycle and increases labor and material consumption, thus driving up the cost.
[0005] Lack of safety monitoring: After sealing, there is a lack of real-time monitoring of groundwater pressure, making it impossible to warn of water pressure fluctuations. The pressure accumulation in the later stages can easily damage the sealing structure, posing a safety hazard to the construction of the basement floor.
[0006] Inadequate waterproofing: The waterproofing layer at the junction of the dewatering well shaft and the raft foundation is weak, making it easy for groundwater to seep along the well wall and causing structural durability problems. Summary of the Invention
[0007] This invention addresses the problems mentioned above by specifically designing a sealing structure and construction method for basement dewatering wells in coastal areas. It utilizes a sealing plate and a micro-expansion concrete layer as a double sealing barrier to reduce the risk of leakage.
[0008] To achieve the above objectives, the present invention provides a sealing structure for basement dewatering wells in coastal areas, comprising a well shaft and a bottom sealing plate. The well shaft is aligned with the wellhead of the dewatering well. The bottom surface of the bottom sealing plate is in contact with the dewatering well, and the bottom sealing plate is annular. Its outer diameter is welded to the inner wall of the well shaft, and a sleeve is fixedly installed on its inner diameter. The inner wall of the sleeve is threaded and connected to a valve. The valve is detachably connected to a pressure gauge. A micro-expansion concrete layer is poured inside the well shaft, and the micro-expansion concrete layer seals the bottom sealing plate, the sleeve, and the valve.
[0009] Furthermore, an intermediate sealing plate is provided inside the wellbore, and the intermediate sealing plate is fixedly connected to the bottom sealing plate by multiple reinforcing ribs.
[0010] Furthermore, an expansion sealing strip is installed on the intermediate sealing plate.
[0011] Furthermore, the inner wall of the well shaft is also welded with a steel mesh, which is cast into the micro-expansion concrete layer.
[0012] Furthermore, the pouring height of the micro-expansion concrete layer is lower than the wellhead height of the well shaft, and a top blind plate is welded at the wellhead.
[0013] Furthermore, a horizontal anti-buoyancy plate is welded to the outer wall of the well shaft, and the anti-buoyancy plate is fixedly connected to the reinforcing steel in the raft foundation.
[0014] This invention also includes a construction method for sealing basement dewatering wells in coastal areas, comprising the following steps: Step 1: Well pre-embedding. The well cylinder is fabricated according to the size of the dewatering well. The well cylinder is aligned with the well opening of the dewatering well, and the perimeter is reinforced by welding the horizontal anti-buoyancy plate to the steel bars in the raft foundation. In step one, sealant and waterproofing material are prepared. The waterproofing material is applied to the middle of the well shaft, and the joint is sealed with sealant to prevent leakage later. Step 2: Initial wellhead sealing. Use a self-priming pump to lower the water level in the well to 30cm below the designed position of the bottom sealing plate. Weld the bottom sealing plate to the inner wall of the well. A round hole is reserved in the middle of the bottom sealing plate for the water pipe of the self-priming pump to extend into for continuous water reduction. After the annular bottom sealing plate is welded, remove the self-priming pump, weld the sleeve to the reserved round hole, and install the valve to form a preliminary seal. Step 3: Water pressure monitoring. Connect a portable pressure gauge to the valve outlet and measure the groundwater pressure regularly until the water pressure stabilizes within the design requirements before proceeding with the floor construction. In step three, the water pressure monitoring frequency is once a day, and the data is recorded in real time and used as a safety basis for the construction of the basement floor. Step 4: Upper sealing. Remove rust from the inner wall of the well and the weld area of the bottom sealing plate and spray anti-rust paint. Wrap the expansion waterstop strip and weld the steel mesh. Pour the micro-expansion concrete layer and vibrate it to make it dense. Leave a 1cm space between the top surface of the concrete layer and the well opening. After the concrete has solidified, weld the top blind plate to the top of the well to achieve a complete seal.
[0015] In summary, the present invention has the following advantages and beneficial technical effects: 1. This invention employs a dual-combination sealing method: welding a steel mesh onto the upper part of the dewatering well wall after initial sealing, followed by pouring concrete for further sealing. This combination of welding and an expansive concrete layer enhances the stability of the seal. Finally, a top blind plate is welded to the dewatering well wall to achieve a complete seal. This sealing method offers significant advantages in both economy and durability. The annular sealing plate, after welding, ensures a complete seal, preventing seepage caused by incomplete sealing of the dewatering well.
[0016] 2. This invention adds a water pressure monitoring component. A water-stop valve is installed on the top of the sleeve, which can be controlled to facilitate monitoring of groundwater pressure. For a period of time after the initial sealing of the dewatering well is completed, a portable pressure gauge is installed on the valve. The pressure gauge data reflects the current water pressure in the basement. Measurements are taken at intervals to see if the groundwater pressure meets the corresponding design requirements, thus ensuring the quality of the project.
[0017] 3. In this invention, the upper sealing process needs to be completed before pouring the ground concrete. Due to the time interval, the well wall of the dewatering well also needs to be derusted and anti-rust paint is sprayed around the well wall to extend its service life.
[0018] 4. The installation of an expansion sealing strip at the weld of the intermediate sealing plate is also an important step in preventing leakage later.
[0019] 5. In this invention, the welding position of the steel mesh needs to be in the middle and lower part of the micro-expansion concrete layer. If the steel mesh is welded too high or too low, it will result in uneven sealing strength in the upper part.
[0020] 6. During the later stages of concrete pouring, thorough vibration is required to ensure a dense space. A 1cm gap should be left between the concrete and the top to allow space for welding the top blind plate. Attached Figure Description
[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of the present invention.
[0022] The reference numerals in the attached figures are: 1. Well shaft; 2. Bottom sealing plate; 3. Dewatering well; 4. Sleeve; 5. Valve; 6. Micro-expansion concrete layer; 7. Intermediate sealing plate; 8. Reinforcing rib; 9. Expansion waterstop strip; 10. Top blind plate; 11. Anti-buoyancy plate; 12. Waterproofing material. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout; the described embodiments are some embodiments of this invention, but not all embodiments; the embodiments and directional terms described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting this invention; all other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings: The following is in conjunction with the appendix Figure 1 The present invention will be further described in detail below: Example 1 like Figure 1 As shown, this embodiment discloses a sealing structure for a basement dewatering well in a coastal area, including a steel well casing 1 and a bottom sealing plate 2. The well casing 1 is aligned with the wellhead of the dewatering well 3. The bottom surface of the bottom sealing plate 2 is in contact with the dewatering well 3, and the bottom sealing plate 2 is annular. Its outer diameter is welded to the inner wall of the well casing 1, and a sleeve 4 is fixedly installed on its inner diameter. The sleeve 4 is preferably made of Q355B grade galvanized steel or 304 stainless steel. The inner wall of the sleeve 4 is threaded and connected to a valve 5. The valve 5 is preferably made of copper and cast iron with an anti-corrosion coating. A pressure gauge is detachably connected to the valve 5. A micro-expansion concrete layer 6 is poured inside the well casing 1. The strength grade of the micro-expansion concrete layer 6 is preferably C35 or C40. After the micro-expansion concrete layer 6 is poured, it seals the bottom sealing plate 2, the sleeve 4, and the valve 5. An intermediate sealing plate 7 is provided inside the well casing 1, and the intermediate sealing plate 7 is fixedly connected to the bottom sealing plate 2 by four reinforcing ribs 8. An expansion sealing strip 9 is installed on the intermediate sealing plate 7. A steel mesh is also welded to the inner wall of the well shaft 1, and the steel mesh is poured into the micro-expansion concrete layer 6. The pouring height of the micro-expansion concrete layer 6 is lower than the wellhead height of the well shaft 1, and a top blind plate 10 is welded to the wellhead. A horizontal anti-buoyancy plate 11 is welded to the outer wall of the well shaft 1, and the anti-buoyancy plate 11 is welded and fixed to the steel reinforcement in the raft foundation.
[0024] Example 2 The construction method of the sealing structure for basement dewatering wells in coastal areas according to the present invention is as follows: Step 1: Before constructing the basement raft foundation, a well cylinder 1 needs to be pre-embedded. The well cylinder 1 with a wall thickness of ≥5mm is processed according to the size of the dewatering well 3. During installation, the well cylinder 1 must be intact and undamaged.
[0025] When pre-embedding the well cylinder 1, ensure that its position is directly aligned with the wellhead of the dewatering well 3. After alignment, steel reinforcement welding must be carried out to ensure that the well cylinder 1 is integrated with the raft foundation through the surrounding horizontal anti-buoyancy plate 11, so as to prevent positional displacement during later concrete pouring.
[0026] During waterproofing construction, the base of the well casing 1 and the expansion waterstop strip 9 in the middle need to be treated in detail. The waterproofing material 12 should be applied to the bottom of the waterstop strip, and the joint should be sealed with sealant to prevent groundwater from seeping from the waterproof part of the well wall later.
[0027] Step 2: Preliminary wellhead sealing. In this embodiment, design planning and material processing preparation are carried out in the early stage. The annular sealing plate is processed according to the cross-sectional dimensions of each dewatering well 3 on site. After the materials arrive on site, the bottom sealing plate 2 and the sleeve 4 are welded into a whole in advance. Then, four reinforcing ribs 8 are welded to provide support for the subsequent welding of the middle sealing plate 7.
[0028] A 1.5kW self-priming pump is used to lower the water level in the well to 30cm below the design position of the bottom sealing plate 2. The bottom sealing plate 2 and the middle sealing plate 7 are welded to the inner wall of the well barrel 1. A 100mm diameter circular hole is reserved in the middle of the bottom sealing plate 2 for the water pipe of the self-priming pump to extend into for continuous water reduction. After the annular sealing plate is welded, the self-priming pump is removed. The upper part of the sleeve 4 is then connected to the valve 5 to form a preliminary seal.
[0029] In this embodiment, preliminary design planning and material processing preparations are carried out. Finished sealing plates are fabricated according to the cross-sectional dimensions of each dewatering well on site. After the materials arrive on site, the bottom sealing plate 2 and the middle sealing plate 3 can be pre-assembled. Step 3: Water pressure monitoring. Connect the portable pressure gauge to the outlet of copper valve 5 and measure the groundwater pressure regularly. The water pressure monitoring frequency is once a day, and the data is recorded in real time until the water pressure stabilizes within the design requirements before the floor construction can proceed. Step 4: Upper sealing. Remove rust from the inner wall of well barrel 1 and the weld area of the annular sealing plate. Then, wrap an expansion waterstop strip 9 around the weld of the middle sealing plate 7. Weld a steel mesh 15cm away from the top of the well opening. After welding, spray anti-rust paint, pour the micro-expansion concrete layer 6, and vibrate it to make it dense. Leave a 1cm space between the top surface of the concrete layer and the well opening. After the concrete has solidified, weld the top blind plate 10 to the top of the well barrel 1 to achieve complete final sealing.
[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A sealing structure for basement dewatering wells in coastal areas, characterized by: The device includes a well casing and a bottom sealing plate. The well casing is aligned with the wellhead of the dewatering well. The bottom surface of the bottom sealing plate is in contact with the dewatering well and is annular. The outer diameter of the bottom sealing plate is welded to the inner wall of the well casing, and a sleeve is fixedly installed on the inner diameter. The inner wall of the sleeve is threaded and connected to a valve. The valve is detachably connected to a pressure gauge. A micro-expansion concrete layer is poured inside the well casing, and the micro-expansion concrete layer seals the bottom sealing plate, the sleeve, and the valve.
2. The sealing structure for basement dewatering wells in coastal areas according to claim 1, characterized in that: An intermediate sealing plate is installed inside the wellbore, and the intermediate sealing plate is fixedly connected to the bottom sealing plate by multiple reinforcing ribs.
3. The sealing structure for basement dewatering wells in coastal areas according to claim 2, characterized in that: An expansion sealing strip is installed on the intermediate sealing plate.
4. The sealing structure for basement dewatering wells in coastal areas according to claim 1, characterized in that: The inner wall of the well shaft is also welded with a steel mesh, which is cast into the micro-expansion concrete layer.
5. The sealing structure for basement dewatering wells in coastal areas according to claim 1, characterized in that: The pouring height of the micro-expansion concrete layer is lower than the wellhead height of the well shaft, and a top blind plate is welded at the wellhead.
6. The sealing structure for basement dewatering wells in coastal areas according to claim 1, characterized in that: The outer wall of the well shaft is welded with a horizontal anti-buoyancy plate, which is fixedly connected to the steel bars in the raft foundation.
7. A construction method for sealing dewatering wells in basements in coastal areas, characterized by: The construction method of the sealing structure for basement dewatering wells in coastal areas as described in claim 1 is as follows: Step 1: Well pre-embedding. The well cylinder is fabricated according to the size of the dewatering well. The well cylinder is aligned with the well opening of the dewatering well, and the perimeter is reinforced by welding the horizontal anti-buoyancy plate to the steel bars in the raft foundation. Step 2: Initial wellhead sealing. Use a self-priming pump to lower the water level in the well to 30cm below the designed position of the bottom sealing plate. Weld the bottom sealing plate to the inner wall of the well. A round hole is reserved in the middle of the bottom sealing plate for the water pipe of the self-priming pump to extend into for continuous water reduction. After the annular bottom sealing plate is welded, remove the self-priming pump, weld the sleeve to the reserved round hole, and install the valve to form a preliminary seal. Step 3: Water pressure monitoring. Connect a portable pressure gauge to the valve outlet and measure the groundwater pressure regularly until the water pressure stabilizes within the design requirements before proceeding with the floor construction. Step 4: Upper sealing. Remove rust from the inner wall of the well and the weld area of the bottom sealing plate and spray anti-rust paint. Wrap the expansion waterstop strip and weld the steel mesh. Pour the micro-expansion concrete layer and vibrate it to make it dense. Leave a 1cm space between the top surface of the concrete layer and the well opening. After the concrete has solidified, weld the top blind plate to the top of the well to achieve a complete seal.
8. The construction method for sealing the basement dewatering well in coastal areas according to claim 7, characterized in that: In step one, sealant and waterproofing material are prepared. The waterproofing material is applied to the middle of the well shaft, and the joint is sealed with sealant to prevent leakage later.
9. The construction method for the sealing structure of basement dewatering wells in coastal areas according to claim 7, characterized in that: In step three, water pressure monitoring is conducted once a day, and the data is recorded in real time and used as a safety basis for basement floor construction.