Reservoir concrete diaphragm wall construction method

Abstract

The invention discloses a reservoir concrete diaphragm wall construction method. The reservoir concrete diaphragm wall construction method comprises the following steps that S1, soil replacement and compaction are conducted in a construction area of a diaphragm wall; s2, a guide groove is excavated in the construction area of the diaphragm wall, and a guide rail and a steel plate moving guide wall are installed; s3, downward construction is carried out along the movable guide wall to form a slotted hole; s4, the groove depth, the hole position deviation and the groove bottom deposition thickness are checked, meanwhile, slurry replacement is conducted in the groove holes, and fresh slurry is supplemented for wall fixing; s5, a mold is placed in the slotted hole, concrete is poured into the mold, and a hollow double-layer concrete diaphragm wall is formed; and S6, after the double-layer concrete anti-seepage wall is solidified, asphalt mixtures are injected into the hollow part of the double-layer concrete anti-seepage wall and gaps between the double-layer concrete anti-seepage wall and the groove walls. According to the method, structural decomposition or performance degradation of asphalt is avoided, and the waterproof performance of the diaphragm wall is improved; in addition, inclination or fracture of the guide grooves can be avoided, and the combination degree of the diaphragm wall and a construction area is enhanced.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, specifically to a construction method for a concrete anti-seepage wall in a reservoir. Background Technology

[0002] Seepage prevention and reinforcement is a major engineering measure for addressing the defects and risks of reservoir dams. Commonly used seepage prevention and reinforcement technologies include grouting seepage prevention and reinforcement technology and cutoff wall reinforcement technology. Among these, high-strength concrete or plastic concrete cutoff wall technology has been widely used in the reinforcement of dam projects and has achieved good results.

[0003] Chinese invention patent CN115874576A discloses a method for constructing a concrete anti-seepage wall, comprising the following steps: determining the construction location of the anti-seepage wall, then excavating a guide trench along the construction area of ​​the anti-seepage wall and filling the guide trench with concrete; after the concrete has solidified, drilling is carried out along the guide trench using a mud-wall drilling method, forming the anti-seepage wall construction trench by first drilling the main hole and then splitting the secondary holes; the anti-seepage wall construction trench is cleaned, and fresh mud is added to solidify the wall; after the mud in the anti-seepage wall construction trench has solidified, a layer of asphalt is applied to the upstream side of the anti-seepage wall construction trench; after the asphalt has solidified, concrete is poured into the anti-seepage wall construction trench to form the anti-seepage wall. In the process of drilling and trenching, this invention sprays asphalt onto the side of the hole closest to the water source, forming an asphalt layer on one side of the hole. After the concrete is poured into the hole, the concrete solidifies and becomes integrated with the asphalt, thereby improving the anti-seepage performance of the anti-seepage wall.

[0004] However, the above-mentioned construction method for the anti-seepage wall has the following problems: 1. When constructing the anti-seepage wall, it is necessary to excavate a guide trench and pour a concrete guide wall of the same length as the anti-seepage wall in the guide trench. However, the concrete guide wall does not have the function of anti-seepage and is only used to assist in excavating the trench. Therefore, it not only wastes a lot of manpower and material resources, but also takes time to construct the concrete guide trench, thus prolonging the completion time of the anti-seepage wall; 2. The asphalt in the above technology is simply coated on one side of the trench. Under the long-term exposure to the soil environment, chemical substances and biological effects, the asphalt may experience structural decomposition or performance degradation, which greatly reduces the waterproof performance of the asphalt and thus reduces the anti-seepage capacity of the entire anti-seepage wall; 3. Due to the varying degrees of soil softness, in some construction sites with loose original soil, large pores and containing acidic or alkaline substances or pollutants, even if a concrete guide trench is constructed, it may tilt or break due to soil problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a construction method for a concrete anti-seepage wall in a reservoir, which solves the problems of the aforementioned technologies requiring the construction of concrete guide channels, resulting in a waste of manpower, material resources, and time, and the tendency for long-term burial of asphalt in the soil to cause a decline in waterproof performance and reduce the anti-seepage capacity of the anti-seepage wall.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a construction method for a concrete anti-seepage wall in a reservoir, comprising the following steps: S1. Excavate a pit in the construction area of ​​the anti-seepage wall, and fill the pit with new soil and filler. When filling the soil, compact each layer with a road roller to improve the bearing capacity of the foundation and make it meet the construction standards. S2. Excavate a guide trench in the construction area of ​​the anti-seepage wall, and embed and install guide rails inside the guide trench. Slide and install steel plates on the guide rails to move the guide wall. S3. By using a rotary drilling machine and a grabbing drilling machine to create holes, grooves are formed by drilling downwards along the moving guide wall. S4. Check the trench depth, hole position deviation and the thickness of silt accumulation at the bottom of the trench. At the same time, replace the mud in the trench hole and add fresh mud to solidify the wall. S5. Place the mold into the slot and pour concrete into the mold to form a hollow double-layer concrete anti-seepage wall. S6. After the double-layer concrete anti-seepage wall has solidified, the crane lifts out the mold and injects asphalt mixture into the hollow of the double-layer concrete anti-seepage wall and the gap between it and the trench wall.

[0007] Preferably, in step S1, the pit needs to be dug down to the stable old soil layer, and the base is trimmed into a stepped shape to enhance the bonding force between the new soil and the original foundation. The new soil needs to be spread layer by layer and mechanically compacted, with the thickness of each layer controlled at 30-50cm to ensure that the density meets the standard. Moreover, the surface of the replaced soil needs to be mechanically leveled to facilitate the construction of the guide device.

[0008] Preferably, in step S2, four light rails are set perpendicular to and parallel to the wall axis on one side of the seepage barrier wall. An excavator is placed on the light rails to excavate guide grooves. Several crossbars with a length of 0.5M are movably installed on the side of the guide rails. When installing the guide rails, the crossbars are inserted into the side of the guide grooves at equal intervals along three horizontal lines. The guide rails are then fixed to the ends of the crossbars. The steel plate moving guide wall is installed onto the guide rails through the cooperation of the strip sliders and the guide rails. The guide rails are composed of several short rails spliced ​​together. There are three guide rails, all of which are parallel to the seepage barrier center line. Three strip sliders are set on the rear side of the steel plate moving guide wall, and the strip sliders slide in cooperation with the guide rails respectively.

[0009] Preferably, before step S3, a slurry is prepared using a mud mixer. The slurry material should meet the following requirements: clay content greater than 50%, plasticity index greater than 20, sand content less than 5%, and a ratio of silica to alumina of 3 to 4.

[0010] Preferably, in step S3, the method of drilling the main hole first and then splitting the secondary hole to form a trench is adopted. The length of the main hole is the minimum designed wall thickness, and the length of the secondary hole is determined according to the geological properties. During construction, the trench wall should be kept flat and vertical, the allowable deviation of the hole center should not exceed 3cm, and the hole inclination should not exceed 0.4%. For the joint hole of the first and second stage trenches, the deviation of any depth of the two hole centers should not exceed 1 / 3 of the wall thickness specified in the construction drawings, and measures should be taken to ensure the designed thickness. During the drilling process, the mud level in the hole should always be kept 30-50cm below the top surface of the moving guide wall to prevent the hole from collapsing.

[0011] Preferably, in step S4, the hole shape should be inspected promptly after the hole is completed. Hole shape inspection generally includes hole position, hole width, hole depth, and hole inclination. At the same time, the hole shape of the main hole, auxiliary hole, and the hole between the two holes should be strictly inspected. The method is as follows: a. Check the axis position along the slot hole and determine the center of the main hole and auxiliary hole; b. Use a steel wire rope to suspend the drill bit and measure the deviation from the center of the hole under its own weight. The diameter of the drill bit is equal to the wall thickness at the depth to be measured; c. From one end of the slot hole, move a measuring point every 20-40cm to the other end. The measuring position at the hole opening should be fixed. Measure the distance and direction of the steel wire rope from the hole opening measuring point to the hole center at different depths. Then, calculate the residual inclination value of a certain bottom section or the bottom of the entire hole based on the principle of similar triangles.

[0012] Preferably, after borehole inspection, a secondary cleaning process is required, using an air-lift reverse circulation method (high-pressure air flushing of the bottom of the trench). During the cleaning process, the crane needs to continuously lift the guide pipe up and down to disturb the rock debris at the bottom of the trench, shorten the cleaning time, and thoroughly remove the silt at the bottom of the borehole. At the same time, the condition of the mud returned from the cleaning process is closely observed. When there are no sediment particles in the returned mud and the mud properties meet the specifications (specific gravity ≤ 1.30, sand content ≤ 12%, viscosity ≤ 30s), a test cake and a test needle are inserted into the borehole. The difference between the borehole depth measured by the test cake and the test needle is the thickness of the silt at the bottom of the borehole. This ensures that the silt and mud indicators meet the specifications. If the specifications are not met, the cleaning process continues until the design requirements are met. Before the completion of the second phase of cleaning and slurry replacement of the trench holes, the mud skin on the concrete hole wall of the joint should be removed. The mud should be washed in sections using a wire brush and drill bit. The qualified standard for washing is that the brush and drill bit are basically free of mud debris and the siltation at the bottom of the hole no longer increases.

[0013] Preferably, the pouring guide pipes are installed after the S4 trench cleaning inspection is passed. Before installation, a water pressure test is conducted on the guide pipes; only guide pipes that pass the test are included in the installation scope. The required guide pipe length is calculated based on the trench depth, and the guide pipes are numbered in advance and assembled to prevent miscalculations during dismantling, which could lead to excessively deep or shallow burial of the guide pipes during pouring. The spacing between adjacent guide pipes is less than 5m, the distance between the guide pipes and both ends is controlled at 1.0-1.5m, and the distance between the guide pipes and the bottom of the trench is controlled at 150-250mm. The joint pipes are arranged at both ends of the first trench. After the first trench pouring guide pipes are laid out, the joint pipes are installed immediately, with the joint pipes close to the ends of the first trench and secured. To prevent drifting during pouring, concrete pouring under slurry requires the use of a straight-lift tremie pipe method with an inner diameter of 200-250mm. When using two sets of tremie pipes for pouring in one trench, the center-to-center distance between the tremie pipes should not exceed 5.0m, and the distance from the center of the tremie pipe to the end of the trench or the wall of the joint should be 1.0-1.5m. When the height difference at the bottom of the trench exceeds 250mm, the tremie pipe should be placed at the lowest point within its control range, and pouring should begin from the lowest point. The pipe joints should use a quick-connect method and undergo a sealing test. Several short pipes with a length of 0.3-1.0m should be installed above the top and bottom sections of each tremie pipe. Before pouring, the distance from the bottom of the tremie pipe to the bottom of the trench should be controlled within the range of 150-250mm.

[0014] Preferably, in step S5, the mold consists of two hollow rectangular structures nested together, which are placed into the slot by a crane. Both the inner and outer surfaces of the mold are coated with a release agent. When pouring concrete, concrete is poured into the gap between the two molds. After the concrete has completely solidified, a hollow wall is formed. The two molds are then lifted out by a crane for demolding. Asphalt is then filled into the hollow of the concrete wall and into the gaps on the front and back sides. After the asphalt has solidified, it is bonded to the wall to form an integral structure.

[0015] Preferably, in step S6, after the asphalt has completely hardened, concrete is poured in place to seal the top of the concrete impermeable wall.

[0016] Preferably, after the concrete anti-seepage wall is constructed, the steel plate guide wall is moved to the adjacent trench section for construction through the cooperation of guide rails and strip sliders.

[0017] This invention provides a method for constructing a concrete anti-seepage wall for a reservoir, which has the following beneficial effects: 1. This invention replaces the traditional concrete guide wall with a movable steel plate guide wall. Only a guide groove needs to be dug out, and there is no need to build a concrete guide wall. The movable guide wall can move along the guide groove, which meets the needs of the excavation and greatly saves the construction cost and time of the guide wall. Moreover, the movable guide wall can be recycled and reused in the later stage, saving resources. 2. This invention uses a mold to cast a hollow concrete anti-seepage wall and fills the inner cavity of the anti-seepage wall with asphalt, sealing the asphalt inside the anti-seepage wall. This prevents the asphalt from undergoing structural decomposition or performance degradation due to long-term exposure to the soil environment, chemical substances, and biological processes, thereby improving the waterproof performance of the anti-seepage wall. 3. This invention strengthens the bearing capacity of the foundation of the construction area by replacing the soil first, enabling it to support large construction equipment. At the same time, it can effectively prevent the guide channel from tilting or breaking, and greatly enhance the bonding between the anti-seepage wall and the construction area, thus helping to improve the construction effect of the anti-seepage wall. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the steel plate movable guide wall of the present invention; Figure 2 This is a cross-sectional schematic diagram of the mold of the present invention.

[0019] In the picture: 1. Crossbar; 2. Guide rail; 3. Moving guide wall; 4. Strip slider; 5. Slot; 6. Mold. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1 and Figure 2 This invention provides a technical solution: a construction method for a concrete anti-seepage wall in a reservoir, comprising the following steps: S1. Excavate a pit in the construction area of ​​the anti-seepage wall, and fill the pit with new soil and filler. When filling the soil, compact each layer with a road roller to improve the bearing capacity of the foundation and make it meet the construction standards. S2. Excavate a guide trench in the construction area of ​​the anti-seepage wall, and embed and install guide rail 2 inside the guide trench. Slide and install steel plate moving guide wall 3 on guide rail 2. S3. By using a rotary drilling machine and a grabbing drilling machine to work together, a slot is formed by drilling downwards along the moving guide wall 3. S4. Check the trench depth, hole position deviation and the thickness of silt accumulation at the bottom of the trench. At the same time, replace the mud in the trench hole and add fresh mud to solidify the wall. S5. Place mold 6 into the slot and pour concrete into mold 6 to form a hollow double-layer concrete anti-seepage wall. S6. After the double-layer concrete anti-seepage wall has solidified, the crane lifts out the mold 6 and injects asphalt mixture into the hollow of the double-layer concrete anti-seepage wall and the gap between it and the trench wall.

[0022] In this embodiment, in step S1, the pit needs to be dug down to the stable old soil layer, and the base needs to be trimmed into a stepped shape to enhance the bonding force between the new soil and the original foundation. The new soil needs to be spread layer by layer and mechanically compacted, with the thickness of each layer controlled at 30-50cm to ensure that the density meets the standard. Moreover, the surface of the replaced soil needs to be mechanically leveled to facilitate the construction of the guide.

[0023] In this embodiment, in step S2, four light rails are set on one side of the seepage barrier wall, perpendicular to and parallel to the wall axis. An excavator is placed on the light rails to dig a guide groove. Several crossbars 1 are movably set on the side of the guide rail 2. The length of the crossbar 1 is 0.5M. When installing the guide rail 2, the crossbars 1 are inserted into the side of the guide groove at equal intervals along three horizontal lines. Then the guide rail 2 is fixed to the end of the crossbar 1. In a preferred embodiment, the end of the crossbar 1 is provided with a slot 5 that corresponds to the guide rail 2. The guide rail can move in the slot 5. The steel plate moving guide wall 3 is installed on the guide rail 2 through the cooperation of the strip slider 4 and the guide rail 2. The guide rail 2 is composed of several short rails spliced ​​together. There are three guide rails 2, all of which are parallel to the seepage barrier center line. Three strip sliders 4 are set on the rear side of the steel plate moving guide wall 3. The strip sliders 4 slide and cooperate with the guide rail 2 respectively.

[0024] In this embodiment, before step S3, a mud mixer is used to prepare the mud. The mud material should meet the following requirements: the clay content should be greater than 50%, the plasticity index should be greater than 20, the sand content should be less than 5%, and the ratio of silica to alumina should be 3 to 4. The mud in the storage tank should be continuously blown and turned with high-pressure air to maintain the uniformity of the mud performance indicators. The performance indicators of the circulated mud should be tested every 30 minutes. When the mud exceeds the specified indicators, it should be treated as waste mud. The waste mud will be discharged into the location designated by the supervisor.

[0025] As a preferred embodiment, during the trenching process, the mud comes into contact with soil and groundwater, which will mix with soil residue and electrolyte ions, causing the mud to become contaminated. In order to ensure the wall protection effect of the mud and the quality of the trench, each batch of new mud and the mud that has been replaced in the trench section are tested and controlled according to the mud performance indicators. Mud that is severely contaminated by cement soaking (pH>10) is treated as waste mud. In this embodiment, in step S3, the method of drilling the main hole first and then splitting the secondary hole to form a groove is adopted. The length of the main hole is the minimum designed wall thickness, and the length of the secondary hole is determined according to the geological properties. During construction, the groove wall should be kept flat and vertical, the allowable deviation of the hole center should not exceed 3cm, and the hole inclination should not exceed 0.4%. For the joint hole of the first and second stage grooves, the deviation of any depth of the hole center should not exceed 1 / 3 of the wall thickness specified in the construction drawings, and measures should be taken to ensure the designed thickness. During the drilling process, the mud level in the hole should always be kept 30-50cm below the top surface of the moving guide wall 3 to prevent the hole from collapsing.

[0026] As a preferred embodiment, the pure grabbing method can be used for construction. The excavated soil grabbed during the trenching process is transported to the designated material yard by dump trucks. During transportation, anti-leakage measures are taken, such as installing waterproof rubber or using waterproof tarpaulins at the door seams to prevent grout leakage during transportation. Water trucks are used to wash the road surface as needed to reduce dust.

[0027] In this embodiment, in step S4, the hole shape should be inspected promptly after the hole is completed. Hole shape inspection generally includes hole position, hole width, hole depth, and hole inclination. Simultaneously, the shapes of the main and auxiliary holes, as well as the holes between them, should be rigorously inspected. The method is as follows: a. Verify the axis position along the slot and determine the center of the main and auxiliary holes; b. Suspend the drill bit with a steel wire rope from the drilling rig, and measure the deviation from the center of the borehole under its own weight. The drill bit diameter is equal to the wall thickness at the desired depth; c. From one end of the slot, move a measuring point every 20-40 cm to the other end. The measuring position at the hole opening should be fixed. Measure the distance and direction of the steel wire rope's deviation from the borehole center at different depths from shallow to deep. Then, calculate the remaining inclination value at a certain bottom section or the entire bottom of the hole using the principle of similar triangles. The following values ​​are obtained:

[0028] Table 1: Inspection Items and Quality Requirements for Trenching In this embodiment, after borehole inspection, borehole cleaning is required. A secondary cleaning is performed using the air-lift reverse circulation method (high-pressure air flushing of the bottom of the trench). During the cleaning process, the crane needs to continuously lift the guide pipe up and down to disturb the rock debris at the bottom of the trench, shorten the cleaning time, and thoroughly remove the silt at the bottom of the borehole. At the same time, the condition of the mud returned from the cleaning is closely observed. When there are no sediment particles in the returned mud and the mud properties have met the specifications (specific gravity ≤ 1.30, sand content ≤ 12%, viscosity ≤ 30s), a test cake and a test needle are inserted into the borehole. The difference between the borehole depth measured by the test cake and the test needle is the thickness of the silt at the bottom of the borehole. This ensures that the silt and mud indicators meet the specifications. If the specifications are not met, the cleaning process continues until the design requirements are met. Before the completion of the second phase of cleaning and slurry replacement of the trench holes, the mud skin on the concrete hole wall of the joint should be removed. The mud should be washed in sections using a wire brush and drill bit. The qualified standard for washing is that the brush and drill bit are basically free of mud debris and the siltation at the bottom of the hole no longer increases.

[0029] In this embodiment, after the S4 trench cleaning is accepted, the pouring guide pipes are installed. Before installation, a water pressure test is conducted on the guide pipes; only guide pipes that pass the test are included in the pipe installation scope. The required guide pipe length is calculated based on the trench depth, and the guide pipes are numbered in advance and assembled to prevent miscalculations during dismantling, which could lead to excessively deep or shallow burial of the guide pipes during the pouring process. The spacing between adjacent guide pipes is less than 5m, the distance between the guide pipes and both ends is controlled at 1.0-1.5m, and the distance between the guide pipes and the bottom of the trench is controlled at 150-250mm. The joint pipes are arranged at both ends of the first trench. After the first trench pouring guide pipes are laid out, the joint pipes are installed immediately, with the joint pipes close to the ends of the first trench and fixed in place. To prevent drifting during pouring, concrete pouring under slurry requires the use of a straight-lift tremie pipe method with an inner diameter of 200-250mm. When using two sets of tremie pipes for pouring in one trench, the center-to-center distance between the tremie pipes should not exceed 5.0m, and the distance from the center of the tremie pipe to the end of the trench or the wall of the joint should be 1.0-1.5m. When the height difference at the bottom of the trench exceeds 250mm, the tremie pipe should be placed at the lowest point within its control range, and pouring should begin from the lowest point. The pipe joints should use a quick-connect method and undergo a sealing test. Several short pipes with a length of 0.3-1.0m should be installed above the top and bottom sections of each tremie pipe. Before pouring, the distance from the bottom of the tremie pipe to the bottom of the trench should be controlled within the range of 150-250mm.

[0030] In this embodiment, in step S5, the mold 6 consists of two hollow rectangular structures nested together. The mold 6 is placed into the slot by a crane, and both the inner and outer surfaces of the mold 6 are coated with a release agent. When pouring concrete, concrete is poured into the gap between the two molds 6. After the concrete has completely solidified, a hollow wall is formed. The two molds 6 are then lifted out by a crane for demolding. Asphalt is then filled into the hollow of the concrete wall and into the gaps on the front and back sides. After the asphalt has solidified, it is integrated with the wall to form an integral structure.

[0031] In this embodiment, in step S6, after the asphalt has completely solidified, concrete is poured on top of the concrete cutoff wall to seal it. As a preferred embodiment, before pouring the asphalt, concrete can be poured into the bottom of the concrete cutoff wall to completely enclose the asphalt inside the concrete cutoff wall and prevent it from directly contacting the soil.

[0032] In this embodiment, after the concrete anti-seepage wall is constructed, the steel plate moving guide wall 3 is moved to the adjacent trench section for construction through the cooperation of the guide rail and the strip slider 4.

[0033] Working principle: This invention replaces the traditional concrete guide wall with a movable steel plate guide wall 3. Only a guide trench needs to be excavated, eliminating the need to construct a concrete guide wall. The movable guide wall 3 can move along the guide trench, fulfilling the trenching requirements and significantly saving construction costs and time. Furthermore, the movable guide wall 3 is recyclable, conserving resources. A hollow concrete anti-seepage wall is cast using a mold 6, and its inner cavity is filled with asphalt, sealing the asphalt within the wall. This prevents structural decomposition or performance degradation of the asphalt due to long-term exposure to soil environment, chemicals, and biological processes, thus improving the anti-seepage wall's waterproof performance. By replacing the soil in the construction area beforehand, the bearing capacity of the foundation is strengthened, enabling it to support large construction equipment. This effectively prevents the guide trench from tilting or breaking and greatly enhances the bond between the anti-seepage wall and the construction area, contributing to a more effective construction outcome.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A construction method for a concrete anti-seepage wall in a reservoir, characterized in that, Includes the following steps: S1. Excavate a pit in the construction area of ​​the anti-seepage wall, and fill the pit with new soil and filler. When filling the soil, compact each layer with a road roller to improve the bearing capacity of the foundation and make it meet the construction standards. S2. Excavate a guide trench in the construction area of ​​the anti-seepage wall, and embed and install a guide rail (2) on the inner side of the guide trench. Slide and install a steel plate on the guide rail (2) to move the guide wall (3). S3. Through the combination of rotary drilling and grabbing drilling, the groove is formed by drilling downward along the moving guide wall (3); S4. Check the trench depth, hole position deviation and the thickness of silt accumulation at the bottom of the trench. At the same time, replace the mud in the trench hole and add fresh mud to solidify the wall. S5. Place the mold (6) into the slot and pour concrete into the mold (6) to form a hollow double-layer concrete anti-seepage wall. S6. After the double-layer concrete anti-seepage wall has solidified, the crane lifts out the mold (6) and injects asphalt mixture into the hollow of the double-layer concrete anti-seepage wall and the gap between it and the trench wall.

2. The construction method for a reservoir concrete anti-seepage wall according to claim 1, characterized in that: In step S2, four light rails are set on one side of the anti-seepage wall, perpendicular to and parallel to the wall axis. An excavator is placed on the light rails to dig a guide groove. Several crossbars (1) are movably set on the side of the guide rail (2). The length of the crossbar (1) is 0.5M. When installing the guide rail (2), the crossbars (1) are inserted into the side of the guide groove at equal intervals along three horizontal lines. Then the guide rail (2) is fixed to the end of the crossbar (1). The steel plate moving guide wall (3) is installed on the guide rail (2) through the cooperation of the strip slider (4) and the guide rail (2). The guide rail (2) is made up of several short rails spliced ​​together. There are three guide rails (2) and they are all parallel to the anti-seepage center line. Three strip sliders (4) are set on the rear side of the steel plate moving guide wall (3). The strip sliders (4) and the guide rail (2) slide and cooperate respectively.

3. The construction method for a reservoir concrete anti-seepage wall according to claim 1, characterized in that: Before step S3, a slurry is prepared using a mud mixer. The slurry material should meet the following requirements: clay content greater than 50%, plasticity index greater than 20, sand content less than 5%, and a silicon dioxide to aluminum oxide ratio of 3 to 4.

4. The construction method for a concrete anti-seepage wall in a reservoir according to claim 1, characterized in that: In step S3, the method of drilling the main hole first and then splitting the secondary hole to form a groove is adopted.

5. The construction method for a concrete anti-seepage wall in a reservoir according to claim 1, characterized in that: In step S4, the hole shape should be inspected promptly after the hole is completed. Hole shape inspection generally includes hole position, hole width, hole depth, and hole inclination; at the same time, the hole shape of the main hole, auxiliary hole, and the hole between the two holes should be strictly inspected.

6. The construction method for a concrete anti-seepage wall in a reservoir according to claim 5, characterized in that: After the borehole inspection, the borehole needs to be cleaned. The air-lift reverse circulation method (high-pressure air flushing the bottom of the trench) is used for secondary cleaning. During the cleaning process, the crane needs to continuously lift the guide pipe up and down to disturb the rock debris at the bottom of the trench and shorten the cleaning time. Before the completion of the second-stage trench cleaning and slurry replacement, the mud skin on the concrete borehole wall of the joint should be removed and the section should be brushed with a wire brush and drill bit.

7. The construction method for a concrete anti-seepage wall in a reservoir according to claim 1, characterized in that: After the S4 trench cleaning is accepted, the pouring guide pipes are installed. Before the guide pipes are installed, a water pressure test is conducted to seal the guide pipes. The joint pipes are arranged at both ends of the first trench. After the first trench pouring guide pipes are laid out, the joint pipes are installed immediately.

8. The construction method for a concrete anti-seepage wall in a reservoir according to claim 7, characterized in that: In step S5, the mold (6) consists of two hollow rectangular structures nested together. The mold (6) is placed into the slot by a crane. The inner and outer surfaces of the mold (6) are coated with a release agent. When pouring concrete, concrete is poured into the gap between the two molds (6). After the concrete has completely solidified, a hollow wall is formed. The two molds (6) are lifted out by a crane to demold. Asphalt is filled into the hollow of the concrete wall and the gaps on the front and back sides. After the asphalt solidifies, it is combined with the wall to form an integral structure.

9. A construction method for a concrete anti-seepage wall in a reservoir according to claim 1, characterized in that: In step S6, after the asphalt has completely hardened, concrete is poured in place to seal the top of the concrete cutoff wall.

10. A method for constructing a concrete anti-seepage wall for a reservoir according to claim 1, characterized in that: After the concrete anti-seepage wall is completed, the steel plate moving guide wall (3) is moved to the adjacent trench section for construction through the cooperation of guide rail (2) and strip slider (4).

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