A method and device for sealing the pre-reserved pressure relief well in a caisson

Abstract

This invention relates to a method and apparatus for sealing a pre-reserved pressure relief well in a caisson. The method includes installing an installation component on a branch pipe on one side of the pressure relief well; extending a first grouting pipe to the bottom of the pressure relief well and a second grouting pipe to the upper end of the well; temporarily sealing the pipe opening at the upper end of the well; performing a first grouting through the first grouting pipe; stopping grouting the first grouting pipe and allowing it to stand after the grout injected into the first grouting pipe has initially solidified; performing a second grouting through the second grouting pipe, with the grouting pressure of the second grouting pipe being greater than that of the first grouting pipe; opening the temporary seal; and slowly pulling the second grouting pipe outwards while grouting in the later stages of the second grouting; and finally removing the installation component. This invention ensures that there is no groundwater in the pressure relief well, achieving a tight seal without precipitation in the surrounding environment. The sealing process significantly reduces grout loss, has low construction costs, and guarantees high construction quality and sealing quality.

Description

Technical Field

[0001] This invention relates to the technical field of building construction, and in particular to a method and device for sealing a pre-reserved pressure relief well in a caisson. Background Technology

[0002] As cities become increasingly modernized, most people choose private cars for transportation, which is convenient and fast, greatly improving their quality of life. However, the rapid development of private cars has led to an insufficient number of existing parking spaces and a continuously increasing parking shortage. At the same time, urban communities face a situation of scarce land resources and dense building distribution, making the planning and construction of traditional parking lots difficult due to insufficient prerequisites. Therefore, building multi-level underground parking garages is essential to alleviate parking problems. Due to the advantages of caisson structures, such as small footprint, no need for dewatering during the sinking process, and minimal environmental disturbance, they can utilize urban corner plots and underground spaces. A single caisson can be equipped with multi-level parking spaces to meet the needs of expanding urban parking capacity, showing broad application prospects.

[0003] In the construction of multi-story underground parking garages, during caisson construction in areas with high water levels, pressure relief wells must be installed inside the caisson to ensure its anti-buoyancy stability during the construction of the internal structure. Water must be continuously pumped out until the internal structure of the caisson is completed. For example... Figure 1 As shown, the large diameter of the pressure relief well 3 affects the construction of the internal structure of the caisson. Before the construction of the internal structure, the excess part of the original pressure relief well 3 needs to be cut off, and the upper part needs to be reinforced with concrete and sealed. An external branch pipe 2 is opened at the waist position of the pressure relief well 3, and a second valve is added to divert the water to the collection well 4 for further dewatering, reducing the risk of the caisson floating. After the construction is completed, the pressure relief well 3 and the branch pipe 2 need to be sealed. The fullness of the seal will directly affect the quality and safety of the caisson structure, and thus affect the structure of the multi-story parking garage.

[0004] Currently, pressure relief wells are typically sealed by grouting. However, before grouting, the groundwater level needs to be lowered to reduce head pressure. Excessive pumping can cause significant ground subsidence in the surrounding area. Furthermore, the dewatering pump must be removed after construction. In high-water areas, if the well is not sealed promptly after removal, the abundant groundwater supply can lead to severe grout leakage during the grouting process. Blindly grouting results in significant waste of grouting material, increases construction costs, and makes complete sealing difficult, requiring subsequent adjustments based on the actual situation, greatly increasing both difficulty and cost. In addition, inadequate grouting can create gaps within the pressure relief well. Prolonged exposure to high pressure, humidity, and groundwater can cause internal corrosion, forming leakage channels. This compromises the durability of the pressure relief well seal, leaving the completed underground parking garage in a damp environment, which can eventually damage the structure. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art, which require a large amount of water pumping before grouting for sealing pressure relief wells, resulting in excessive surface subsidence. In high water level areas, if the well is not sealed in time after the dewatering pump is removed, the groundwater level will be replenished quickly, causing serious grout leakage during the grouting process, increasing construction costs, making it difficult to completely seal and making gaps easy to appear. Under long-term high pressure, humidity and groundwater immersion, pressure relief wells are prone to internal corrosion, forming leakage channels, and the durability of pressure relief well sealing cannot be guaranteed.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for sealing a pre-reserved pressure relief well in a caisson, including...

[0007] S1: Install the mounting component on one side of the branch pipe of the pressure relief well, extend the first grouting pipe into the bottom of the pressure relief well, and extend the second grouting pipe horizontally along the branch pipe to the upper end of the pressure relief well. Temporarily seal the pipe opening at the upper end of the pressure relief well. Perform the first grouting through the first grouting pipe. When the liquid at the outlet of the mounting component is detected to be a thick grouting substance, stop grouting the first grouting pipe and let it stand.

[0008] S2: After the grouting material injected into the first grouting pipe has initially set, a second grouting is performed through the second grouting pipe, and the grouting pressure of the second grouting pipe is greater than that of the first grouting pipe. The temporary seal is opened, and during the later stage of the second grouting, the second grouting pipe is slowly pulled outward while grouting.

[0009] S3: Remove the installation components.

[0010] In one embodiment of the present invention, during step S1, when the first grouting pipe is inserted into the bottom of the decompression well and the second grouting pipe is extended horizontally along the branch pipe to the upper end of the decompression well, the outlet is in a fully open state.

[0011] In one embodiment of the present invention, when the first grouting begins in step S1, the opening of the outlet is appropriately reduced, and when the liquid at the outlet is a viscous grouting substance, grouting to the first grouting pipe is stopped.

[0012] In one embodiment of the present invention, after the grouting material in the pressure relief well and the branch pipe has been cured, the installation components are removed and the first grouting pipe is cut off.

[0013] In one embodiment of the present invention, the grouting material is a micro-expansion concrete slurry with a water-cement ratio greater than or equal to a set value.

[0014] A sealing device for a pre-reserved pressure relief well in a caisson is constructed using the sealing construction method for a pre-reserved pressure relief well in a caisson as described in any of the above embodiments. It includes a connector, a tee pipe, an end cap, a first grouting pipe, and a second grouting pipe. One end of the connector is connected to a branch pipe of the pressure relief well, and the other end is connected to the tee pipe. A first valve for controlling the discharge of liquid is installed at the first interface of the tee pipe, and the end cap is provided at the second interface of the tee pipe. A first grouting pipe for the first grouting and a second grouting pipe for the second grouting are threaded through the end cap. A sealing element for temporary sealing is provided near the upper end of the second grouting pipe of the pressure relief well.

[0015] In one embodiment of the present invention, a counterweight head is provided at the end of the first grouting pipe near the bottom of the decompression well, and a set distance is spaced between the end of the first grouting pipe and the counterweight head.

[0016] In one embodiment of the present invention, the seal is fixed to the port of the second grouting pipe near the upper end of the pressure relief well. When the grouting pressure of the second grouting pipe is greater than the grouting pressure of the first grouting pipe, the seal is ruptured.

[0017] In one embodiment of the present invention, the end cap is provided with a first through hole for the first grouting pipe to pass through and a second through hole for the second grouting pipe to pass through, wherein the diameter of the first through hole is larger than the diameter of the first grouting pipe and the diameter of the second through hole is larger than the diameter of the second grouting pipe.

[0018] In one embodiment of the present invention, the tee pipe includes a first fitting, a second fitting, and a fastening fitting, wherein the first fitting and the second fitting are combined by the fastening fitting to form the tee pipe.

[0019] The technical solution of the present invention has the following advantages compared with the prior art:

[0020] The present invention describes a method and apparatus for sealing a pre-reserved pressure relief well in a caisson. An installation component is installed at one end of a branch pipe of the pressure relief well. A first grouting is performed through a first grouting pipe, followed by a second grouting through a second grouting pipe. These two grouting operations ensure the fullness of the grouting material inside the pressure relief well, thus completing the sealing operation. Specifically, after installing the installation component, a temporary seal is applied to the end of the second grouting pipe, acting as a check valve. The first grouting pipe is extended to the bottom of the pressure relief well, and the temporarily sealed end of the second grouting pipe is extended horizontally to the top of the pressure relief well. Grouting begins on the first grouting pipe, which is in a temporarily sealed state. Groundwater and a small amount of diluted grouting material continuously drain from the outlet of the installation component. The first grouting is complete when the liquid at the outlet of the installation component is detected to be a viscous grouting material. After the grout injected into the first grouting pipe has initially set, grouting begins in the second grouting pipe. Because the grouting pressure in the second grouting pipe is greater than that in the first, the temporary seal is broken, filling the pressure relief well with grout. This increases the density of the pressure relief well grout seal and ensures a dense filling within the branch pipe. Finally, the installation components are removed. This construction method, through two grouting processes, ensures no groundwater in the pressure relief well, allowing for sealing even without surrounding dewatering. In water-rich geological conditions or with large water inflows, it can successfully seal the pressure relief well and branch pipe. The sealing process significantly reduces grout loss, resulting in low construction costs. It also ensures no cavities or gaps within the well, eliminating the need for subsequent treatment and guaranteeing construction quality. The branch pipe is also densely filled, resulting in a high-quality seal and further protecting the building within the underground parking garage. Attached Figure Description

[0021] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Figure 1 This is a schematic diagram of an existing pressure relief well.

[0023] Figure 2 This is a schematic diagram of the structure for installing the sealing components in the caisson pre-reserved pressure relief well sealing construction method of the present invention;

[0024] Figure 3 This is a schematic diagram of the first grouting in the caisson pre-reserved pressure relief well sealing construction method of the present invention;

[0025] Figure 4 This is a structural schematic diagram of the second grouting process in the caisson pre-reserved pressure relief well sealing construction method of the present invention;

[0026] Figure 5 This is a schematic diagram of the final sealing structure in the caisson reserved pressure relief well sealing construction method of the present invention;

[0027] Figure 6 for Figure 2 An enlarged view of part A in the caisson pre-reserved pressure relief well sealing construction method of the present invention;

[0028] Figure 7 for Figure 2 An enlarged view of part B in the construction method for sealing the pre-relief well in the caisson of this invention;

[0029] Figure 8 This is a schematic diagram of the tee pipe in the caisson pre-reserved pressure relief well sealing construction method of the present invention;

[0030] Explanation of reference numerals in the accompanying drawings: 1. Sealing assembly; 11. Connector; 12. T-joint; 121. First interface; 122. Second interface; 123. Third interface; 124. First fitting; 125. Second fitting; 126. Fastening element; 13. First grouting pipe; 131. Counterweight head; 14. Second grouting pipe; 141. Sealing element; 15. First valve; 16. End cap; 2. Branch pipe; 3. Pressure relief well; 4. Water collection well. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0032] Example 1

[0033] Please refer to Figure 2-8 As shown, the present invention provides a method for sealing a pre-reserved pressure relief well in a caisson, including...

[0034] S1: Install the mounting component on the branch pipe 2 on one side of the pressure relief well 3, extend the first grouting pipe 13 into the bottom of the pressure relief well 3, and extend the second grouting pipe 14 horizontally along the branch pipe 2 to the upper end of the pressure relief well 3. Temporarily seal the pipe opening at the upper end of the pressure relief well 3. Perform the first grouting through the first grouting pipe 13. When the liquid at the outlet of the mounting component is detected to be a thick grouting substance, stop grouting the first grouting pipe 13 and let it stand.

[0035] S2: After the grouting material injected into the first grouting pipe 13 has initially set, a second grouting is carried out through the second grouting pipe 14, and the grouting pressure of the second grouting pipe 14 is greater than that of the first grouting pipe 13. The temporary seal is opened, and during the later stage of the second grouting, the second grouting pipe 14 is slowly pulled outward while grouting.

[0036] S3: Remove the installation components.

[0037] This construction method involves installing an installation component at one end of the branch pipe 2 of the pressure relief well 3, performing an independent first grouting through the first grouting pipe 13, and an independent second grouting through the second grouting pipe 14. These two grouting operations ensure the fullness of the grouting material inside the pressure relief well 3, thus completing the sealing operation. Specifically, after installing the installation component, a temporary seal is applied to the end of the second grouting pipe 14, which acts as a check valve. The first grouting pipe 13 is extended to the bottom of the pressure relief well 3, and the temporarily sealed end of the second grouting pipe 14 is extended horizontally to the top of the pressure relief well 3. Grouting begins on the first grouting pipe 13, while the second grouting pipe 14 remains temporarily sealed. Groundwater and a small amount of diluted grouting material continuously drain from the outlet of the installation component. The first grouting is complete when the liquid at the outlet of the installation component is detected to be a viscous grouting material. After the grouting material injected into the first grouting pipe 13 has initially set, grouting begins into the second grouting pipe 14. Since the grouting pressure of the second grouting pipe 14 is greater than that of the first grouting pipe 13, the temporary seal is opened, and grouting material is added to the pressure relief well 13, increasing the density of the grouting in the well and ensuring a dense filling within the branch pipe 2. Finally, the installation components are removed. This construction method, through two grouting processes, ensures that there is no groundwater in the pressure relief well 3, allowing for sealing of the well 3 even without precipitation in the surrounding environment. In water-rich geological conditions or with large water inflows, the pressure relief well 3 and branch pipe 2 can be successfully sealed. The sealing process significantly reduces grouting material loss, resulting in low construction costs. It also ensures no cavities or gaps within the well, eliminating the need for subsequent treatment and guaranteeing construction quality. The branch pipe 2 is also densely filled, resulting in a high-quality seal and further protecting the building within the underground parking garage.

[0038] Specifically, before installing the mounting components, the operator needs to estimate and prepare the grouting material required for sealing based on the actual conditions of the pressure relief well 33. The grouting material can be micro-expansion concrete grout with a water-cement ratio greater than or equal to a set value, which can be 0.7, to ensure reinforcement during the sealing process. During the process of extending the first grouting pipe 13 into the bottom of the pressure relief well 3 and the second grouting pipe 14 horizontally extending along the branch pipe 2 to the upper end of the pressure relief well 3, the outlet is fully open, allowing for active drainage. Simultaneously, the water pump in the sump 4 is turned on to pump out the overflowing groundwater. The fully open outlet ensures normal pressure and prevents danger within the pressure relief well 3.

[0039] When starting the first grouting, the opening of the outlet should be appropriately reduced. During the process of extending the first grouting pipe 13 into the bottom of the decompression well 3 and the second grouting pipe 14 horizontally to the top of the decompression well 3, the outlet is in a fully open state. At this time, the groundwater level is high and the water pressure is large. Under the condition of high water flow, the grouting material (micro-expansion concrete slurry) will be lost and diluted too quickly, which will cause the grouting material to fail to achieve the design purpose of dense sealing. Therefore, during the first grouting process, the opening of the outlet can be appropriately reduced to decrease the overflow, but it should not be completely closed. This will allow a small amount of groundwater to overflow from the outlet, and the overflow water will gradually mix with the micro-expansion concrete slurry. In this embodiment, the pressure inside the first grouting pipe 13 is 0.5 MPa. When the first grouting is about to end, and the liquid at the outlet is a thick grouting substance, stop grouting the first grouting pipe 13 and let it stand for about an hour. Then close the outlet opening to allow the grouting substance (micro-expansion concrete slurry) to initially set. The specific time can be adjusted appropriately according to the actual situation.

[0040] Furthermore, the first condition is that the liquid at the discharge outlet is a viscous grouting material or that the groundwater overflow at the discharge outlet is significantly reduced. That is, when the groundwater overflow at the discharge outlet is significantly reduced or the grouting material is viscous, this state indicates that the grouting material (micro-expansion concrete grout) is fully filled, and grouting of the first grouting pipe 13 is stopped. At the same time, both the first grouting pipe 13 and the second grouting pipe 14 are waterproof grouting pipes. The first grouting pipe 13 is a high-pressure grouting hose, and the second grouting pipe 14 is a rigid PE pipe. This setting ensures safety when sealing the pressure relief well 3.

[0041] Specifically, after the grout injected into the first grouting pipe 13 has initially set, grouting is performed into the second grouting pipe 14. When the pressure inside the second grouting pipe 14 increases, the temporarily sealed port of the second grouting pipe 14 is opened, and the grout overflows from inside the second grouting pipe 14. In this embodiment, the grouting pressure in the second grouting pipe 14 is adjusted to 1 MPa, which is greater than the grouting pressure in the first grouting pipe 13. The purpose is to fill the area that was not compacted after the first grouting. During the initial grouting process in the second grouting pipe 14, the pipe remains stationary. Subsequently, as... Figure 4 As shown, while grouting, the second grouting pipe 14 is slowly pulled out to ensure that the branch pipe 2 is also filled tightly. After two grouting operations, the water stoppage in the pressure relief well 3 is completed, with no gaps or other phenomena, and the sealing is reliable.

[0042] In addition, after the grouting material in the pressure relief well 3 and branch pipe 2 has been cured, the installation components can be removed by tapping them with a chisel. After removing the installation components, the excess first grouting pipe 13 is cut off, and a ring of concrete is wrapped around the outside of the branch pipe 2 to prevent the exposed branch pipe 2 outside the pressure relief well 3 from rusting.

[0043] Example 2

[0044] A sealing device for a pre-reserved pressure relief well in a caisson is constructed using the sealing construction method for the pre-reserved pressure relief well 3 in any of the above embodiments, such as... Figure 2-8 As shown, it includes a connector 11, a tee pipe 12, an end cap 16, a first grouting pipe 13, and a second grouting pipe 14. One end of the connector 11 is connected to the branch pipe 2 of the pressure relief well 3, and the other end is connected to the tee pipe 12. The first port 121 of the tee pipe 12 is equipped with a first valve 15 for controlling the discharge of liquid. The second port 122 of the tee pipe 12 is provided with an end cap 16. The end cap 16 is provided with a first grouting pipe 13 for the first grouting and a second grouting pipe 14 for the second grouting. The second grouting pipe 14 is provided with a sealing element 141 for temporary sealing near the upper end of the pressure relief well 3.

[0045] The implementation process of this device is as follows: First, install the sealing component 1. Connect the branch pipe 2 located on the waist side of the pressure relief well 3 to the connector 11. Install the first valve 15 at the first port 121 of the tee pipe 12. Install the end cap 16 at the second port 122 of the tee pipe 12. Insert the first grouting pipe 13 and the second grouting pipe 14 into the end cap 16. Connect the third port 123 of the tee pipe 12 to the connector 11. Start the first grouting by opening the first valve 15, allowing the first grouting pipe 13 to extend into the bottom of the pressure relief well 3. The end of the temporarily sealed second grouting pipe 14 extends horizontally to the corner between the pressure relief well 3 and the branch pipe 2, which is the pressure relief well 3. At the upper end, grouting begins through the first grouting pipe 13, and the first valve 15 is adjusted. When the groundwater overflow at the first interface 121 of the tee pipe 12 decreases significantly or the grouting material becomes viscous, grouting of the first grouting pipe 13 is stopped and allowed to stand, and the first valve 15 is closed. After the grouting material injected into the first grouting pipe 13 has initially set, grouting begins through the second grouting pipe 14, and the grouting pressure of the second grouting pipe 14 is greater than that of the first grouting pipe 13. During the initial grouting process, the second grouting pipe 14 remains stationary. Subsequently, the second grouting pipe 14 is slowly pulled out while grouting continues. Finally, the sealing component 1 is removed.

[0046] The device performs sealing operations by installing a sealing component 1 at one end of the branch pipe 2 of the pressure relief well 3. The end of the second grouting pipe 14 is temporarily sealed and can be used as a check valve during the first grouting process. When the first valve 15 is opened, most of the groundwater in the pressure relief well 3 flows out through the first interface 121 of the tee pipe 12 after being diverted, and the groundwater overflow on the end cap 16 is relatively small. The first valve 15 is adjusted, and the first grouting pipe 13 is extended into the bottom of the pressure relief well 3. The second grouting pipe 14 is extended horizontally, and the temporarily sealed end is extended to the upper end of the pressure relief well 3. Grouting of the first grouting pipe 13 begins. When the groundwater overflow at the first interface 121 of the tee pipe 12 is significantly reduced or the grouting material becomes thick, the first grouting is completed. After the grouting material has initially set, grouting begins in the second grouting pipe 14. Since the grouting pressure in the second grouting pipe 14 is greater than that in the first grouting pipe 13, it increases the density of the pressure relief well and ensures a dense filling within the branch pipe 2. Finally, the sealing component 1 is removed. This construction method, through two grouting processes, ensures that there is no groundwater in the pressure relief well 3. It can achieve the sealing of the pressure relief well 3 without dewatering in the surrounding environment. In water-rich geological conditions or with large water inflow, it can successfully seal the pressure relief well 3 and the branch pipe 2, while ensuring that there are no cavities or gaps within the well and no need for subsequent treatment, thus guaranteeing construction quality.

[0047] In this embodiment, as Figure 6 As shown, a sealing element 141 is provided at the end of the second grouting pipe 14. The sealing element 141 is installed at the end of the second grouting pipe 14 by binding. When the grouting pressure of the second grouting pipe 14 is greater than the grouting pressure of the first grouting pipe 13, the sealing element 141 will rupture after grouting of the second grouting pipe 14. The sealing element 141 can be a plastic bag. The plastic bag is tied to the end that will be inserted into the pressure relief well 3, that is, the end at the corner of the pressure relief well 3 and the branch pipe 2. In the first grouting process, the plastic bag binding can be used as a check valve. In the second grouting process, the end of the second grouting pipe 14 can be opened by increasing the grouting pressure to start the second grouting. The material is readily available, the cost is low, and the practicality is high.

[0048] Furthermore, connector 11 is a thin-walled double-threaded pipe clamp with external threads. Since the branch pipe 2 of the pressure relief well 3 contains internal threads, one end of the double-threaded pipe clamp can be screwed onto the branch pipe 2 of the pressure relief well 3. Figure 7As shown, a counterweight head 131 is provided at the end of the first grouting pipe 13, and the counterweight head 131 is extended into the pressure relief well 3. The setting of the counterweight head 131 can ensure that after the first grouting pipe 13 passes through the branch pipe 2, the first grouting pipe 13 can smoothly and as far as possible extend into the interior of the pressure relief well 3 under the gravity of the counterweight head 131. There is a set distance between the end of the first grouting pipe 13 and the counterweight head 131. This set distance can be adjusted according to the actual situation inside the pressure relief well 3 and the grouting pressure. The setting of this set distance can prevent the grout from causing blockage of the first grouting pipe opening 13 during the grouting process.

[0049] In this embodiment, as Figure 8 As shown, the tee pipe 12 includes a first fitting 124, a second fitting 125, and a fastening member 126. The first fitting 124 and the second fitting 125 are combined by the fastening member 126 to form the tee pipe 12. Furthermore, the end cap 16 has a first through hole for the first grouting pipe 13 and a second through hole for the second grouting pipe 14. The diameter of the first through hole is larger than the diameter of the first grouting pipe 13, and the diameter of the second through hole is larger than the diameter of the second grouting pipe 14. That is, the outer diameter of the first grouting pipe 13 is slightly smaller than the inner diameter of the first through hole on the end cap 16, and the outer diameter of the second grouting pipe 14 is slightly smaller than the inner diameter of the second through hole on the end cap 16, facilitating installation.

[0050] Furthermore, the tee pipe 12 has a two-part structure. After being combined with the external thread thin-walled double-headed threaded pipe clamp, the outer circumference is tightened by multiple hose clamps to form a whole, which facilitates installation and disassembly. When disassembling, the hose clamps are loosened, and a rubber hammer is used to strike the joint of the tee pipe 12 with a chisel to make it fall off.

[0051] Specifically, before the third port 123 of the tee pipe 12 is connected to the connector 11, the second valve on the branch pipe 2 is removed, and the first valve 15 is in the open state, allowing the first valve 15 to actively drain the water. At the same time, the water pump in the collection well 4 is simultaneously turned on to pump out the overflowing groundwater. When the end cap 16 with a through hole is connected to the second port 122 of the tee pipe 12, since the first valve 15 is in the open state, most of the groundwater flows out through the first port 121 after being drained, and the overflow of groundwater through the end cap 16 with the through hole is relatively small. In addition, when the first grouting pipe 13 extends into the pressure relief well 3 and the end of the second grouting pipe 14 is tied and extended to the corner between the pressure relief well 3 and the branch pipe 2, the first valve 15 is in the fully open state to ensure normal pressure and avoid danger in the pressure relief well 3.

[0052] When the first grouting begins, the first valve 15 should be adjusted to a smaller size. When the first grouting pipe 13 is extended into the pressure relief well 3 and the second grouting pipe 14 is extended to the corner of the pressure relief well 3 and the branch pipe 2, the first valve 15 is fully open. At this time, the groundwater level is high and the water pressure is high. Under the condition of high water flow, the grouting material (micro-expansion concrete slurry) will be lost and diluted too quickly, which will cause the grouting material to fail to achieve the design purpose. Therefore, during the first grouting process, the first valve 15 can be appropriately reduced to decrease the overflow, but it should not be completely closed. This will allow a small amount of water to overflow from the first valve 15, and the overflow water will gradually mix with the micro-expansion concrete grout. At this time, in this embodiment, the pressure in the first grouting pipe 13 is 0.5 MPa. When the first grouting is about to end, the opening of the first valve 15 should be appropriately increased and quickly adjusted back to its original state. When the groundwater overflow at the first valve 15 is significantly reduced or the grouting material becomes thick, this state indicates that the micro-expansion concrete grout is fully filled. Grouting of the first grouting pipe 13 should be stopped, and it should be left to stand for about an hour. Then, the first valve 15 should be closed to allow the micro-expansion concrete grout to initially set. The specific time can be adjusted appropriately according to the actual situation.

[0053] Specifically, after the micro-expansion concrete grout injected into the first grouting pipe 13 has initially set, grouting is performed into the second grouting pipe 14. When the pressure in the second grouting pipe 14 is increased, the plastic bag tied to its end can be ruptured by the pressure, and the grout overflows from the pipe. In this embodiment, the grouting pressure in the second grouting pipe 14 is adjusted to 1 MPa, which is greater than the grouting pressure in the first grouting pipe 13. The purpose is to fill the area that was not compacted after the first grouting. During the initial grouting process in the second grouting pipe 14, the pipeline remains stationary. Subsequently, as... Figure 4 As shown, while grouting, the second grouting pipe 14 is slowly pulled out to ensure that the branch pipe 2 is also filled tightly. After two grouting operations, the water stoppage in the pressure relief well 3 is completed, with no gaps or other phenomena, and the sealing is reliable.

[0054] In addition, such as Figure 5 As shown, during the removal of the sealing component 1, the tee pipe 12 is retained after the second grouting. After the grouting material in the pressure relief well 3 and branch pipe 2 has cured, the tee pipe 12 is removed. It can be detached by striking the tee pipe 12 with a chisel, and the excess first grouting pipe 13 is cut off. After removing the sealing component 1, a ring of concrete is wrapped around the outside of the branch pipe 2 to prevent corrosion of the exposed branch pipe 2 outside the pressure relief well 3.

[0055] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for sealing a pre-reserved pressure relief well in a caisson, characterized in that: A sealing device is adopted, comprising a connector, a tee pipe, an end cap, a first grouting pipe, and a second grouting pipe. The first grouting pipe is a high-pressure grouting hose, and the second grouting pipe is a rigid PE pipe. One end of the connector is connected to the branch pipe of the pressure relief well, and the other end is connected to the tee pipe. The first port of the tee pipe is equipped with a first valve for controlling the discharge of liquid, and the second port of the tee pipe is provided with the end cap. The end cap is provided with a first grouting pipe for the first grouting and a second grouting pipe for the second grouting. The second grouting pipe is close to the upper end of the pressure relief well and is provided with a sealing element for temporary sealing. The construction method includes the following steps: S1: Install a sealing device on a branch pipe on one side of the pressure relief well, extend the first grouting pipe into the bottom of the pressure relief well, and extend the second grouting pipe horizontally along the branch pipe to the upper end of the pressure relief well, and temporarily seal the pipe opening at the upper end of the pressure relief well. Perform the first grouting through the first grouting pipe. When the liquid at the outlet of the sealing device is detected to be a thick grouting substance, stop grouting the first grouting pipe and let it stand. S2: After the grouting material injected into the first grouting pipe has initially set, a second grouting is performed through the second grouting pipe, and the grouting pressure of the second grouting pipe is greater than that of the first grouting pipe. The temporary seal is opened, and during the later stage of the second grouting, the second grouting pipe is slowly pulled outward while grouting. S3: Remove the sealing device; In step S1, when the first grouting begins, the opening of the first valve is appropriately reduced. When the first grouting is about to end, the opening of the first valve is appropriately increased. When the outlet liquid is a thick grouting substance, the grouting of the first grouting pipe is stopped. S4: Cut off the excess first grouting pipe and wrap a ring of concrete around the outside of the branch pipe.

2. The method for sealing the pre-reserved pressure relief well in a caisson according to claim 1, characterized in that: In step S1, as the first grouting pipe is inserted into the bottom of the decompression well and the second grouting pipe is extended horizontally along the branch pipe to the upper end of the decompression well, the outlet is in a fully open state.

3. The method for sealing the pre-reserved pressure relief well in a caisson according to claim 1, characterized in that: After the grouting material in the pressure relief well and branch pipe has been cured, the sealing device is removed and the first grouting pipe is cut off.

4. The method for sealing the pre-reserved pressure relief well in a caisson according to claim 1, characterized in that: The grouting material is a micro-expansion concrete slurry with a water-cement ratio greater than or equal to a set value.

5. A device for sealing a pre-reserved pressure relief well in a caisson, characterized in that: The construction is carried out using the sealing method for the pre-reserved pressure relief well of the caisson as described in any one of claims 1-4, which includes a connector, a tee pipe, an end cap, a first grouting pipe and a second grouting pipe. One end of the connector is connected to the branch pipe of the pressure relief well, and the other end is connected to the tee pipe. A first valve for controlling the discharge of liquid is installed at the first interface of the tee pipe, and the end cap is provided at the second interface of the tee pipe. A first grouting pipe for the first grouting and a second grouting pipe for the second grouting are passed through the end cap. The second grouting pipe is close to the upper end of the pressure relief well and is provided with a sealing element for temporary sealing.

6. The sealing device for the pre-relief well in a caisson according to claim 5, characterized in that: A counterweight is provided at the end of the first grouting pipe near the bottom of the decompression well, and a set distance is provided between the end of the first grouting pipe and the counterweight.

7. The sealing device for the pre-relief well in a caisson according to claim 5, characterized in that: The seal is fixed to the port of the second grouting pipe near the upper end of the pressure relief well. When the grouting pressure of the second grouting pipe is greater than the grouting pressure of the first grouting pipe, the seal is ruptured.

8. The sealing device for the pre-relief well in a caisson according to claim 5, characterized in that: The end cap is provided with a first through hole for the first grouting pipe to pass through and a second through hole for the second grouting pipe to pass through. The diameter of the first through hole is larger than the diameter of the first grouting pipe, and the diameter of the second through hole is larger than the diameter of the second grouting pipe.

9. The sealing device for the pre-relief well in a caisson according to claim 5, characterized in that: The tee pipe includes a first fitting, a second fitting, and a clamping fitting, wherein the first fitting and the second fitting are combined by the clamping fitting to form the tee pipe.

Images