Well sealing construction method for high-pressure-bearing dewatering well of theater platform bin foundation pit

Abstract

The invention discloses a well sealing construction method for a high-pressure-bearing dewatering well of a theater platform bin foundation pit. According to the well sealing construction method, a sealing tool composed of a ball valve, a disc steel plate plug, an upper metal short pipe and a lower metal short pipe is manufactured; the specification of each part of the plugging tool is selected according to the underground water pressure so as to meet the plugging requirement; the dewatering well pipe is cut to the bottom plate face of the platform bin, a groove is ground and chiseled along the periphery of the upper edge of a well mouth, and steel bar planting holes are formed; the plugging tool extends into the dewatering well pipe to plug the well pipe, and water is pumped; fine stone micro-expansion impervious concrete is poured into the dewatering well pipe and vibrated densely, a reinforcing mesh is arranged at a groove, an anti-crack glass fiber mesh and waterproof mortar are sequentially covered till the top elevation of a bottom plate of the platform bin, and well pipe plugging is completed. According to the method, the problem that the dewatering well is difficult to seal in the high confined water layer is effectively solved, the used materials are common building materials, construction operation is simple, well sealing operation efficiency is improved, and construction cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering construction, and in particular to a sealing construction method for a high-pressure dewatering well in a theater stage warehouse foundation pit. Background Art

[0002] In theater venue projects, the stage warehouse is used to provide space for the installation and operation of stage machinery, such as stage lifts and other equipment. These equipment can realize various functions such as lifting, translation, and rotation of the stage within the space of the stage warehouse, thereby enriching the stage's performance. Therefore, the location of the stage warehouse is basically designed to be deep directly below the stage. It is characterized by being deep and large, and is often the deepest point of the venue's foundation pit project. Therefore, in the stage warehouse foundation pit project in water-rich areas, the dewatering pressure there is also the greatest. It is also necessary to reserve a dewatering well pipe at the bottom plate of the stage warehouse for dewatering construction during the project construction. After the superstructure construction is completed and the top plate is covered with soil, the heavy pressure load meets the design requirements, the well sealing construction can be carried out.

[0003] Usually, in order to reduce the pressure of the confined water on the platform warehouse floor, multiple drainage wells will be cut into the platform warehouse floor surface before the platform warehouse roof is covered with soil. They will not be closed temporarily to relieve pressure and reduce water, ensuring the structural safety of the platform warehouse before the main body reaches the design load, as an anti-floating measure. When the construction is completed and the wells need to be sealed, because the sealing position of the drainage well pipe is located in the confined water layer, the groundwater in the large area of the platform warehouse can only be relieved from the drainage well pipes left, so the pressure is often huge. At this time, the problem of difficulty in sealing the wells will arise, and as the number of remaining well pipes decreases, the difficulty of sealing the wells increases exponentially. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a sealing construction method for a high-pressure dewatering well in a theater stage warehouse foundation pit. This method effectively solves the problem of difficulty in sealing dewatering wells in high-pressure water layers. The materials used are commonly used in construction, the construction operation is simple, the sealing operation efficiency is improved, and construction costs are saved.

[0005] In order to solve the above technical problems, the present invention provides a method for sealing a high-pressure dewatering well in a theater stage base pit, comprising the following steps: Step 1: Make a plugging tool, including a ball valve, a disc steel plate plug, an upper metal short pipe and a lower metal short pipe. The upper metal short pipe and the lower metal short pipe are respectively arranged at the output end and the input end of the ball valve. The surface of the disc steel plate plug is evenly distributed with several steel ridges along the radial direction, and a groove is set on the outer edge. The disc steel plate plug is centrally welded to the outer ring of the lower metal short pipe and is located below the ball valve. The diameter of the disc steel plate plug is consistent with the inner diameter of the dewatering well pipe. Step 2: Calculate the groundwater pressure in the dewatering well pipe by the groundwater rising height per unit time. Select the specifications of the circular steel plate plug, metal short pipe, and ball valve according to the groundwater pressure to ensure that they can withstand the water pressure after the ball valve is closed. Calculate the length of the lower metal short pipe to allow the water level in the well pipe to drop to a certain depth, thereby reducing the impact of water pressure on the circular steel plate plug after the ball valve is closed and before concrete pouring is completed. Step 3: Cut the drainage well pipe to 50mm below the bottom plate of the platform. Grind the slope of the platform bottom plate within 100mm around the upper edge of the well mouth and chisel it. Arrange several rebar holes evenly and obliquely in the concrete around the well mouth. Step 4: Extend the lower metal short pipe downward into the precipitation well pipe, with the circular steel plate plug 400mm away from the top surface of the platform warehouse bottom plate. The upper metal short pipe is upward and connected to the vacuum water pump to pump water, so that the water level in the precipitation well pipe is lower than the circular steel plate plug. The edge of the circular steel plate plug is fully welded to the inner wall of the precipitation well pipe. Stop pumping half an hour after welding, close the ball valve, and remove the upper metal short pipe; Step 5. Pour fine stone micro-expansive anti-seepage concrete into the dewatering well pipe, vibrate it to make it dense, insert steel bars when pouring to the bottom of the rebar hole and cross them to form a steel mesh, press the steel mesh into the lower concrete, and then continue pouring until the steel mesh is completely covered. Press a layer of circular anti-cracking fiberglass mesh on the top, cover it with a layer of waterproof mortar until the top elevation of the platform warehouse bottom plate, complete the well pipe sealing, and maintain it according to the requirements of anti-seepage concrete.

[0006] Furthermore, the diameters of the upper metal short tube and the lower metal short tube are 50 mm, the length of the upper metal short tube is 200 mm, the length of the lower metal short tube is 600 mm, and the disc steel plate plug is fully welded to the outer ring of the lower metal short tube.

[0007] Furthermore, after the circular steel plate plug is welded to the inner wall of the dewatering well pipe, an air compressor is used to pass compressed air into the well pipe, and a high thermal conductivity copper block or aluminum block is placed on the surface of the circular steel plate plug to quickly cool the heat of the weld and reduce the risk of weld brittle cracking and open welding when pressurized water rises.

[0008] Furthermore, after the circular steel plate plug is welded to the inner wall of the dewatering well pipe, an infrared thermometer is used to monitor the cooling of the weld, and it should be ensured that the weld does not come into contact with the upwelling pressurized water before the temperature drops to at least 150°C.

[0009] Furthermore, a quick connector is provided at the top end of the upper metal short tube, and the vacuum water pump is connected to the quick connector via a hose.

[0010] Furthermore, during the pouring and compacting process of the fine stone micro-expansion anti-seepage concrete in the precipitation well pipe, damage to the welds of the ball valve and the disc steel plate plug should be avoided to cause water leakage and pressure relief.

[0011] Furthermore, the order of sealing the pressure-bearing dewatering wells in the Taicang foundation pit is to gradually close them from the periphery to the middle of the Taicang foundation pit, and finally 3 to 4 dewatering wells are sealed at the same time, with the dewatering wells with high water pressure being sealed first. Since the sealing construction method of the theater stage pit high-pressure dewatering well of the present invention adopts the above-mentioned technical scheme, that is, the method makes a sealing tool composed of a ball valve, a disc steel plate plug, an upper metal short pipe and a lower metal short pipe; the specifications of the various components of the sealing tool are selected according to the groundwater pressure to meet the needs of sealing; the dewatering well pipe is cut to the stage bottom plate surface, the upper edge of the well mouth is polished and roughened, and the anchor holes are arranged; the sealing tool is extended into the dewatering well pipe to seal the well pipe and pump water; fine stone micro-expansion anti-seepage concrete is poured into the dewatering well pipe and vibrated to make it dense, a steel mesh is set at the groove, and anti-cracking fiberglass mesh and waterproof mortar are sequentially covered until the top elevation of the stage bottom plate to complete the well pipe sealing. This method effectively solves the problem of difficult sealing of dewatering wells in high-pressure water layers, and the materials used are all commonly used building materials, the construction operation is simple, the sealing operation efficiency is improved, and the construction cost is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Figure 1 Schematic diagram of the sealing construction method of the high-pressure dewatering well in the theater stage base pit of the present invention; Figure 2 Schematic diagram of the disc steel plate plug of the plugging tooling in this method; DETAILED DESCRIPTION

[0013] Implementation example Figure 1 and Figure 2 As shown in the figure, the sealing construction method of the high-pressure dewatering well of the theater stage warehouse foundation pit of the present invention includes the following steps: Step 1: Make a plugging tool, including a ball valve 1, a disc steel plate plug 2, an upper metal short tube 3 and a lower metal short tube 4. The upper metal short tube 3 and the lower metal short tube 4 are respectively arranged at the output end and the input end of the ball valve 1. The surface of the disc steel plate plug 2 is evenly distributed with a number of steel ridges 21 along the radial direction, and a groove 22 is set on the outer edge. The disc steel plate plug 2 is centrally welded to the outer ring of the lower metal short tube 3 and is located below the ball valve 1. The diameter of the disc steel plate plug 2 is consistent with the inner diameter of the dewatering well pipe 5; The steel ridges on the surface of the disc steel plate plug can resist the pressure of pressurized water, reduce deformation and avoid cracking without increasing the overall thickness of the disc steel plate; the outer edge groove can improve the strength of the weld, shortening the welding time between the disc steel plate plug and the inner wall of the well pipe, improving the weld quality, and thus enhancing the ability to resist pressurized water pressure; Step 2: Calculate the groundwater pressure in the dewatering well pipe 5 by the groundwater rising height per unit time, select the specifications of the circular steel plate plug 2, the metal short pipes 3 and 4, and the ball valve 1 according to the groundwater pressure, so that they can meet the ability to resist the water pressure after the ball valve 1 is closed, and calculate the length of the lower metal short pipe 4 so that the water level in the well pipe can be lowered to a certain depth, thereby reducing the impact of the water pressure on the circular steel plate plug 2 after the ball valve 1 is closed and before the concrete is poured; Step 3: Cut the drainage well pipe 5 to 50mm below the surface of the platform bottom plate 6, grind the slope 7 of the platform bottom plate 6 inclined to the well mouth within 100mm around the upper edge of the well mouth and chisel it, and evenly arrange several rebar holes in the concrete around the well mouth; Step 4: Extend the lower metal short tube 4 downward into the precipitation well pipe 5, the circular steel plate plug 2 is 400mm away from the top surface of the platform warehouse bottom plate 6, the upper metal short tube 3 is upward and connected to the vacuum water pump 8 to pump water, so that the water level in the precipitation well pipe 5 is lower than the circular steel plate plug 2, the edge of the circular steel plate plug 2 is fully welded to the inner wall of the precipitation well pipe 5, stop pumping water half an hour after welding is completed, close the ball valve 1, and remove the upper metal short tube 3; Step 5: Pour fine stone micro-expansion anti-seepage concrete into the dewatering well pipe 5, vibrate and compact it, insert steel bars when pouring to the bottom of the anchor hole and cross them to form a steel mesh 9, press the steel mesh 9 into the lower concrete, and then continue pouring until it is completely covered with the steel mesh 9 and then stop. Press a layer of circular anti-cracking fiberglass mesh on the top and cover it with a layer of waterproof mortar until the top elevation of the platform warehouse bottom plate 6, complete the well pipe sealing, and maintain it according to the requirements of anti-seepage concrete.

[0014] Preferably, the diameters of the upper metal short tube 3 and the lower metal short tube 4 are 50 mm, the length of the upper metal short tube 3 is 200 mm, the length of the lower metal short tube 4 is 600 mm, and the disc steel plate plug 2 is fully welded to the outer ring of the lower metal short tube 4.

[0015] Preferably, after the circular steel plate plug 2 is welded to the inner wall of the dewatering well pipe 5, an air compressor is used to pass compressed air into the well pipe, and a high thermal conductivity copper block or aluminum block is placed on the surface of the circular steel plate plug 2 to quickly cool the heat of the weld and reduce the risk of weld brittle cracking and open welding when pressurized water rises.

[0016] Preferably, after the circular steel plate plug 2 is welded to the inner wall of the dewatering well pipe 5, an infrared thermometer is used to monitor the cooling of the weld, and it should be ensured that the weld does not contact the upwelling pressurized water before the temperature drops to at least 150°C.

[0017] Preferably, a quick connector 31 is provided at the top end of the upper metal short tube 3 , and the vacuum water pump 8 is connected to the quick connector 31 via a hose 81 .

[0018] Preferably, during the pouring and vibrating process of the fine stone micro-expansion anti-seepage concrete in the dewatering well pipe 5, damage to the welds of the ball valve 1 and the disc steel plate plug 2 is avoided to cause water leakage and pressure relief.

[0019] Preferably, the order of sealing the pressure-bearing dewatering wells of the Taicang foundation pit is to gradually seal them from the periphery to the middle of the Taicang foundation pit, and finally 3 to 4 dewatering wells are sealed at the same time, with the dewatering wells with high water pressure being sealed first.

[0020] For underground water pressure changes greatly due to tidal influence, there is still a risk of leakage due to the plugging material being pushed open after using this method to seal. When pouring concrete to the top of the pipe, a circular steel plate with the same diameter as the well pipe can be welded to enhance the sealing effect.

[0021] The vacuum pump power used in this method should be sufficient to ensure that the groundwater upwelling velocity is less than the pumping speed when welding the circular steel plate plug inside the wellbore. This ensures proper welding and welding quality of the circular steel plate plug and prevents unreliable welding that could be broken by water pressure, leading to plugging failure. Alternatively, skilled welders can be selected to conduct welding tests, including welding quality and welding time, to infer welding and cooling times, and the vacuum pump power can be selected accordingly.

[0022] This method effectively solves the problem of sealing precipitation wells in high-pressure water layers. The materials used are common materials on the market, easy to purchase and obtain, and simple to operate. It has a good sealing effect, saves costs, and improves construction efficiency.

Claims

1. A method for sealing a high-pressure dewatering well in a theater stage base pit, characterized in that The steps include: Step 1: Make a plugging tool, including a ball valve, a disc steel plate plug, an upper metal short pipe and a lower metal short pipe. The upper metal short pipe and the lower metal short pipe are respectively arranged at the output end and the input end of the ball valve. The surface of the disc steel plate plug is evenly distributed with several steel ridges along the radial direction, and a groove is set on the outer edge. The disc steel plate plug is centrally welded to the outer ring of the lower metal short pipe and is located below the ball valve. The diameter of the disc steel plate plug is consistent with the inner diameter of the dewatering well pipe. Step 2: Calculate the groundwater pressure in the dewatering well pipe by the groundwater rising height per unit time. Select the specifications of the circular steel plate plug, metal short pipe, and ball valve according to the groundwater pressure to ensure that they can withstand the water pressure after the ball valve is closed. Calculate the length of the lower metal short pipe to allow the water level in the well pipe to drop to a certain depth, thereby reducing the impact of water pressure on the circular steel plate plug after the ball valve is closed and before concrete pouring is completed. Step 3: Cut the drainage well pipe to 50mm below the bottom plate of the platform. Grind the slope of the platform bottom plate within 100mm around the upper edge of the well mouth and chisel it. Arrange several rebar holes evenly and obliquely in the concrete around the well mouth. Step 4: Extend the lower metal short pipe downward into the precipitation well pipe, with the circular steel plate plug 400mm away from the top surface of the platform warehouse bottom plate. The upper metal short pipe is upward and connected to the vacuum water pump to pump water, so that the water level in the precipitation well pipe is lower than the circular steel plate plug. The edge of the circular steel plate plug is fully welded to the inner wall of the precipitation well pipe. Stop pumping half an hour after welding, close the ball valve, and remove the upper metal short pipe; Step 5. Pour fine stone micro-expansive anti-seepage concrete into the dewatering well pipe, vibrate it to make it dense, insert steel bars when pouring to the bottom of the rebar hole and cross them to form a steel mesh, press the steel mesh into the lower concrete, and then continue pouring until the steel mesh is completely covered. Press a layer of circular anti-cracking fiberglass mesh on the top, cover it with a layer of waterproof mortar until the top elevation of the platform warehouse bottom plate, complete the well pipe sealing, and maintain it according to the requirements of anti-seepage concrete.

2. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized by: The diameters of the upper metal short tube and the lower metal short tube are 50 mm, the length of the upper metal short tube is 200 mm, and the length of the lower metal short tube is 600 mm. The disc steel plate plug is fully welded to the outer ring of the lower metal short tube.

3. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized by: After the circular steel plate plug is welded to the inner wall of the dewatering well pipe, an air compressor is used to introduce compressed air into the well pipe, and a high thermal conductivity copper block or aluminum block is placed on the surface of the circular steel plate plug to quickly cool the heat of the weld and reduce the risk of weld brittle cracking and open welding when pressurized water rises.

4. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized by: After the circular steel plate plug is welded to the inner wall of the dewatering well pipe, an infrared thermometer is used to monitor the cooling of the weld. It should be ensured that the weld does not come into contact with the upwelling pressurized water before the temperature drops to at least 150°C.

5. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized in that: A quick connector is provided at the top end of the upper metal short tube, and the vacuum water pump is connected to the quick connector via a hose.

6. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized by: During the pouring and compacting of fine stone micro-expansion anti-seepage concrete in the precipitation well pipe, avoid damaging the welds of the ball valve and the disc steel plate plug to cause water leakage and pressure relief.

7. The method for sealing a high-pressure dewatering well in a theater stage base pit according to claim 1 is characterized by: The order of sealing the pressure-bearing dewatering wells in the Taicang foundation pit is to gradually close them from the periphery to the middle of the Taicang foundation pit. Finally, 3 to 4 dewatering wells are sealed at the same time, and the dewatering wells with high water pressure are sealed first.

Images