Anchord cable water leakage prevention method based on membrane bag plugging

Abstract

The present application belongs to the technical field of anchor cable water leakage prevention, and particularly relates to an anchor cable water leakage prevention method based on membrane bag plugging. The prevention method plugs the membrane bag steel pipe at the anchor cable orifice to make the first grouting be pressure grouting, and the grout enters the deep soil layer. The membrane bag steel pipe component comprises a membrane bag and a steel pipe. The membrane bag is wrapped in the middle section of the steel pipe. An inlet and outlet are arranged in the middle section of the side wall of the steel pipe. The membrane bag grouting pipe in the steel pipe is connected to the inlet and outlet to make the membrane bag grouting pipe communicate with the membrane bag. A first grouting pipe, a supplementary grouting pipe and a second grouting pipe are further arranged in the steel pipe. The anchor cable structure is sleeved into the membrane bag steel pipe to a predetermined position. The membrane bag steel pipe component and the anchor cable structure are connected as a whole through early strength agent. The membrane bag steel pipe and the anchor cable are lowered into the grouting borehole. Grouting is performed on the membrane bag steel pipe component to make the membrane bag expand and close the anchor cable hole. The anchor cable borehole anti-seepage effect is improved, and the long-term durability of the anti-seepage effect is ensured.

Description

Technical Field

[0001] This invention belongs to the field of anchor cable leakage prevention technology, specifically relating to an anchor cable leakage prevention method based on membrane bag sealing. Background Technology

[0002] In recent years, with the successive construction of subway projects in my country, water seepage and leakage in the anchor cables of various rail transit stations has become a critical problem that urgently needs to be solved. When conventional cement grouting is used, the cement grout is lost with the incoming water flow, failing to effectively form a cement grout body and thus failing to achieve the purpose of water blocking. Step-by-step grouting reinforcement of anchor cables is not very effective in preventing seepage and leakage. Water seepage and leakage in anchor cable structures is a common technical problem faced in rail transit. The main difficulties of ordinary step-by-step grouting of anchor cables in failing to achieve the purpose of preventing seepage and leakage are as follows: (1) The area of ​​the anchor cable hole on the back of the retaining pile is rich in water. Due to the water pressure difference between the inside and outside of the anchor cable hole, during the grouting construction, the grout in a certain range of the area of ​​the anchor cable hole on the back of the hole is lost with the groundwater. The grout in a certain range of the hole hole area cannot be statically solidified, thus causing water leakage at the hole hole.

[0003] (2) The grouting is pressureless during the first grouting, which has no compaction effect on the strata around the borehole. Therefore, there will be a certain loose influence zone in the borehole, which causes groundwater to seep from the anchor cable hole through the gap, resulting in poor grouting effect.

[0004] (3) The effect of grouting stop is limited in the first grouting, resulting in low pressure of secondary grouting, making it impossible to carry out high-pressure filling, making it difficult to close the water channel and failing to achieve the effect of compacting the soil layer, thus affecting subsequent pressure grouting.

[0005] (4) During the tensioning of the anchor cable, the filling may be damaged by the cement stone body that may have a free section, thus forming a new water-conducting channel.

[0006] Therefore, there is an urgent need for a method that can both ensure the grouting effect and effectively control anchor cable leakage. Summary of the Invention

[0007] The technical problem to be solved by this invention is to provide a method for preventing anchor cable leakage based on membrane bag sealing. By expanding and sealing the anchor cable orifice with a membrane bag, the first grouting is pressurized, and the grout effectively enters the deep soil layer and pores. At the same time, it reinforces the soil layer, controls the seepage of groundwater, and also ensures the effect of subsequent grouting, effectively controlling the occurrence of anchor cable leakage in rail transit construction.

[0008] The technical solution adopted is as follows: A method for preventing anchor cable leakage based on membrane bag sealing includes a membrane bag steel pipe component. The first grouting is pressurized by expanding and sealing the anchor cable orifice with the membrane bag steel pipe, allowing the grout to penetrate deep into the soil layer. The membrane bag steel pipe includes a membrane bag and a steel pipe. The membrane bag wraps around the middle section of the steel pipe, and an inlet / outlet is provided in the middle section of the steel pipe's side wall. The membrane bag grouting pipe inside the steel pipe is connected to the inlet / outlet, thus connecting the membrane bag grouting pipe to the membrane bag. The steel pipe also contains a primary grouting pipe, a supplementary grouting pipe, and a secondary grouting pipe. The prevention and control method includes the following specific steps: (1) Fabricate membrane bag steel pipe components and grout and drill anchor cable holes; (2) Determine the fixed position of the membrane bag steel pipe component by measurement, and insert the anchor cable structure into the membrane bag steel pipe to the predetermined position; (3) An early-strength agent is used inside the steel pipe to connect the membrane bag steel pipe component and the anchor cable structure into a whole; (4) Insert the membrane bag steel pipe and anchor cable into the grouting borehole; (5) Prepare the membrane bag grouting equipment and connect the grouting pipeline; (6) Grout the steel pipe component of the membrane bag to expand the membrane bag and seal the anchor cable hole; (7) For the anchor cable, during the first grouting process, the supplementary grouting borehole can be used as a free outflow pipe. The first grouting can be stopped after the grout flows out. (8) Grout the supplementary grouting pipe; (9) Perform secondary pressurized grouting on the anchor cable.

[0009] Preferably, the membrane bag steel pipe component is positioned at the anchor cable opening.

[0010] Preferably, the membrane bag steel pipe component is sealed at the anchor cable hole opening, so that the first grouting is pressurized and the grout can enter the anchoring section of the borehole and penetrate into the deep soil layer and the pores of the soil layer.

[0011] Preferably, the diameter and length of the steel pipe component of the membrane bag are adapted to the anchor cable hole.

[0012] Preferably, in step (3), the bottom of the membrane bag steel pipe component is sealed with sulfoaluminate cement paste. After the bottom is sealed and cured, sulfoaluminate cement slurry is poured in from the top. After the slurry is cured, the membrane bag steel pipe component and the anchor cable structure are connected as a whole.

[0013] Preferably, in step (7), when grout flows out of the supplementary grouting borehole during the grouting process, it indicates that the first grouting in the hole has been completed and subsequent operations can be carried out.

[0014] Preferably, after the first grouting, a second grouting can only be performed after the grout has cured. Generally, this requires waiting for more than 24 hours.

[0015] Preferably, the length of the supplementary grouting pipe is longer than the length of the steel pipe, or slightly longer than the length of the steel pipe.

[0016] Preferably, a ball valve or an automatic valve is installed on the grouting pipe of the membrane bag.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses a membrane bag and steel pipe component to seal and fix the deep part of the anchor cable borehole, and sets up a reserved supplementary grouting pipe to realize high-pressure supplementary grouting after the first grouting. This can effectively compact the stratum, reduce the stratum permeability coefficient, and form a good seepage prevention system with the grout, the compacted stratum, and the waterproof structure. Secondly, the sealing and filling effect of the membrane bag and supplementary grouting provides high-pressure grouting conditions for secondary grouting, ensuring that the water-conducting channels in the borehole are effectively compacted, improving the anchoring effect, and increasing the seepage prevention effect of the anchor cable borehole. Furthermore, based on the sealing effect of the membrane bag and steel pipe component, the supplementary grouting can use single-component cement grout, which can ensure the long-term durability of the seepage prevention effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the anchor cable waterstop structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the membrane bag steel pipe component in an embodiment of the present invention; Figure 3 This is a schematic diagram of the membrane bag steel pipe component after grouting expansion according to an embodiment of the present invention.

[0019] In the diagram, 1-drilled pile section, 2-TRD seepage prevention and reinforcement section, 3-soil layer inside and outside the station, 4-membrane bag, 5-steel pipe, 6-membrane bag grouting pipe, 7-supplementary grouting pipe, 8-primary grouting pipe, 9-secondary grouting pipe, 10-anchor cable, 11-binding steel wire, 12-entrance / exit, 13-ball valve, 14-grouting material, 15-sealing material. Detailed Implementation

[0020] The accompanying drawings are for illustrative purposes only; certain well-known structures and their descriptions, as well as prior art, may be omitted from the drawings and therefore should not be construed as limiting the invention; the names of orientations are not limited to those described in the embodiments. To clearly illustrate the technical effects of the present invention, the present invention will be described in detail below through embodiments.

[0021] In this embodiment, the main focus is on preventing and controlling the damage to the water-stopping structure. By grouting to seal the failed parts of the water-stopping structure and performing high-pressure grouting on the stratum behind the water-stopping structure, the stratum can be effectively compacted, reducing the stratum permeability coefficient and achieving the purpose of preventing water leakage from the anchor cable borehole.

[0022] During construction, a membrane bag sealing process is adopted. The steel pipe membrane bag is fixed to the anchor cable structure. The fixing position of the membrane bag steel pipe component is measured and determined. The anchor cable structure is inserted into the membrane bag steel pipe component to the predetermined position. The anchor cable is then lowered and placed into the drilled hole. At this time, the membrane bag is grouted and sealed. Then, the first grouting begins. The grouting hole can be used as a free outflow pipe. The first grouting can be stopped after the grout flows out. Then, the supplementary grouting pipe is used for grouting. Finally, the second grouting needs to be carried out after the first grouting has cured, which usually requires waiting for more than 24 hours before the second grouting is carried out.

[0023] The expansion and sealing of the membrane bag allows the injected grout to compact the underlying layer, while also reinforcing loose and weak areas near the borehole. The membrane bag effectively seals the failure points of the water-stop structure, and high-pressure grouting behind the water-stop structure effectively compacts the stratum, reduces the formation permeability coefficient, and achieves the goal of preventing water leakage in anchor cable boreholes. See the anchor cable water-stop structure section... Figure 1 ; like Figure 2 As shown, the membrane bag steel pipe component includes a membrane bag 4 and a steel pipe 5. The membrane bag 4 wraps around the middle section of the steel pipe 5. An inlet / outlet 12 is provided in the middle section of the side wall of the steel pipe 5. The membrane bag grouting pipe 6 inside the steel pipe 5 is connected to the inlet / outlet 12, so that the membrane bag grouting pipe 6 is connected to the membrane bag 4. The membrane bag grouting pipe 6 is equipped with a ball valve 13. The steel pipe 5 is also equipped with a primary grouting pipe 8, a supplementary grouting pipe 7, and a secondary grouting pipe 9. Anchor cable 10 passes through the steel pipe 5 and is connected to the steel pipe 5.

[0024] This invention utilizes the sealing of the membrane bag steel pipe component to enable pressurized grouting during the primary grouting process. This allows the grout to penetrate deeper into the soil layers and simultaneously provides the necessary pressure environment for secondary grouting. This secondary grouting effectively seals the water-conducting channels, preventing seepage. Furthermore, it compacts any damage to the waterstop wall, further preventing seepage.

[0025] The invention will be further illustrated below with reference to engineering examples.

[0026] The grouting scheme employs secondary grouting, using a cement-water glass dual-liquid grout, and sealing is achieved using membrane bag and steel pipe components. The membrane bag 4 is secured with binding wire 11, and the steel pipe 5 is 50cm long, used only for deep sealing in the TRD section. The membrane bag 4 is made of filter cloth, and the grouting pipe 6 connects to the membrane bag 4. The specific steps are as follows: First, fabricate the membrane bag steel pipe components and drill anchor cable holes; The grouting pipe anchor cable is inserted into the steel pipe. Next, the position of the membrane bag steel pipe component fixed to the anchor cable is measured and determined. The bottom of the steel pipe is sealed with sulfoaluminate cement paste. After the seal cures, sulfoaluminate cement grout is poured in from the top. After the grout cures, the membrane bag steel pipe component and the anchor cable structure can be connected as a whole. The sulfoaluminate cement used has micro-expansion properties, ensuring the sealing of the membrane bag steel pipe component.

[0027] The prepared membrane bag steel pipe components and anchor cables are sent into the borehole so that the membrane bag steel pipe components are positioned at the location of the waterstop wall.

[0028] Connect the grouting pipe and tie the connection with wire to prevent the connection from slipping during the pressure grouting process, which would cause grout loss.

[0029] Prepare the grouting equipment and adjust the grouting pressure gauge; the connection method between the grouting equipment and the present invention, and the grouting method, adopt existing technologies. To perform grouting operation on the membrane bag steel pipe, the grouting equipment is first connected to the membrane bag grouting pipe 6. The membrane bag 4 (filter cloth in this embodiment) wrapped around the steel pipe 5 will expand as grouting is performed. Then, the ball valve 13 on the membrane bag grouting pipe 6 is closed to prevent grout backflow.

[0030] Subsequently, the anchor cable is grouted once. Due to the sealing of the membrane bag, the grouting is pressurized, which can better fill the duct and better bond the anchor rod with the surrounding soil. During the anchor cable grouting process, the supplementary grouting hole can be used as a free outflow pipe. The grouting can be stopped after the grout flows out.

[0031] After completing one grouting, grout the supplementary grouting pipe.

[0032] Secondary grouting. Secondary grouting needs to be carried out after the primary grouting has cured, usually requiring more than 24 hours of curing before the secondary grouting is performed.

[0033] Furthermore, in this step (7), the length of the supplementary grouting pipe is slightly longer than the length of the membrane bag steel pipe, and it only works at the non-anchored end.

[0034] During the grouting process described above, pay attention to the pressure gauge reading to prevent the grouting pipe from bursting.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly. Unless otherwise specified, conventional methods such as bolts, rivets, and welding, which are mature technologies in the prior art, are used. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preventing water leakage in anchor cables based on membrane bag sealing, characterized in that, The system includes a membrane bag and steel pipe component. The first grouting is pressurized by expanding and sealing the anchor cable borehole with the membrane bag and steel pipe, allowing the grout to penetrate deep into the soil layer. The membrane bag and steel pipe component comprises a membrane bag and a steel pipe. The membrane bag wraps around the middle section of the steel pipe, and an inlet / outlet is provided in the middle section of the steel pipe's side wall. The membrane bag grouting pipe inside the steel pipe is connected to the inlet / outlet, thus connecting the membrane bag grouting pipe to the membrane bag. The steel pipe also contains a primary grouting pipe, a supplementary grouting pipe, and a secondary grouting pipe. The prevention and control method includes the following specific steps: (1) Fabricate the membrane bag steel pipe component and grout and drill anchor cable holes; wherein the membrane bag steel pipe component is arranged at the position of the anchor cable hole opening; (2) Determine the fixed position of the membrane bag steel pipe component by measurement, and insert the anchor cable structure into the membrane bag steel pipe to the predetermined position; (3) The membrane bag steel pipe component and the anchor cable structure are connected as a whole by an early strength agent inside the steel pipe. Specifically, the bottom of the membrane bag steel pipe component is sealed with sulfoaluminate cement paste. After the bottom is sealed and cured, sulfoaluminate cement slurry is poured in from the top. After the slurry is cured, the membrane bag steel pipe component and the anchor cable structure are connected as a whole. (4) Insert the membrane bag steel pipe component and anchor cable into the grouting borehole; (5) Prepare the membrane bag grouting equipment and connect the grouting pipeline; (6) Grout the steel pipe component of the membrane bag to expand the membrane bag and seal the anchor cable hole; (7) For the first grouting of the anchor cable, during the first grouting process, the supplementary grouting borehole is used as a free outflow pipe. The first grouting is stopped after the grout flows out. During the grouting process, when grout flows out of the supplementary grouting borehole, it means that the first grouting in the hole has been completed and subsequent operations can be carried out. After the first grouting, the second grouting can only be carried out after the grout has solidified. (8) Grout the supplementary grouting pipe; (9) Perform secondary pressurized grouting on the anchor cables; The length of the supplementary grouting pipe is longer than that of the steel pipe, and a ball valve or an automatic valve is installed on the membrane bag grouting pipe.

2. The method for preventing water leakage in anchor cables based on membrane bag sealing according to claim 1, characterized in that, The membrane bag steel pipe component is sealed at the anchor cable hole, so that the first grouting is pressurized and the grout can enter the anchoring section of the borehole and enter the deep soil layer and the pores of the soil layer.

3. The anchor cable leakage prevention method based on membrane bag sealing according to claim 1, characterized in that, The diameter and length of the steel pipe component of the membrane bag are adapted to the anchor cable hole.

Images