Underground diaphragm wall construction method

Abstract

The invention relates to the technical field of underground diaphragm wall construction, in particular to an underground diaphragm wall construction method. According to the method, through the steps of surveying and setting out, construction of a guide wall and a construction platform, slurry preparation and management, grooving construction, sediment removal and slurry replacement, lowering of a connector pipe, lowering of a reinforcement cage, insertion of a guide pipe, underwater concrete pouring, pulling of the connector pipe and the like, effective management of slurry and accurate control of a groove wall in the construction process are ensured, and the construction efficiency and quality are improved; the construction cost is reduced, the construction period is shortened by optimizing connection of all procedures, and the safety and reliability of the whole project are improved.

Description

Technical Field

[0001] The present application relates to the technical field of underground construction, and in particular to a method for constructing an underground continuous wall. Background Art

[0002] In the field of construction, underground continuous walls, as an important basic engineering technology, are widely used in the construction of large-scale infrastructure such as high-rise buildings, subways, bridges, etc. Underground continuous walls can not only effectively resist groundwater infiltration, but also enhance the foundation stability of buildings, improve construction quality and safety, reduce construction costs, and shorten construction periods. With the acceleration of urbanization and technological advancement, underground continuous walls are increasingly widely used under complex geological conditions, and their construction technology has also been continuously optimized and improved.

[0003] During the construction of underground continuous walls, a series of construction techniques and measures are usually adopted to ensure the stability of the wall and the quality of the project. Common construction methods include trenching, mud wall protection, steel cage production and hoisting, underwater concrete pouring, etc. Trenching is one of the key links in the construction of underground continuous walls, mainly including the selection of trenching machines, the arrangement of trenching sequence, and the preparation and management of mud. For example, the selection of trenching machines is usually based on geological conditions and construction requirements. Commonly used trenching machines include grab trenching machines and rotary trenching machines. The trenching sequence is generally to construct the starting trench section first, then the middle trench section, and finally the closed trench section. Mud wall protection is to inject high-quality mud into the slot hole to form a wall protection mud skin to prevent the trench wall from collapsing and ensure the verticality and flatness of the trench. In addition, the production and hoisting of the steel cage are also important links to ensure the quality of the underground continuous wall. It is necessary to ensure the production accuracy and hoisting accuracy of the steel cage. Underwater concrete pouring is to inject concrete through the catheter after the steel cage is hoisted into place to ensure uniform distribution and full filling of concrete.

[0004] However, the existing underground continuous wall construction method still has some shortcomings in practical application. Especially in the trenching construction process, due to the influence of factors such as complex geological conditions and harsh construction environment, trench wall collapse and low trenching accuracy are prone to occur. These problems will not only affect the construction progress, but also lead to a decline in project quality and increase construction risks. Therefore, how to improve the stability and accuracy of trenching construction has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present application provides an underground continuous wall construction method, which can improve the stability and accuracy of trenching construction.

[0006] This application is implemented through the following technical solutions: A method for constructing an underground continuous wall comprises the following steps: Survey and set out: survey the construction site, set out along the longitudinal axis of the underground continuous wall design, and mark the contour edge of the guide wall enclosure structure design on both sides of the longitudinal axis of the continuous wall design; Guide wall and construction platform construction: dig a guide ditch along the designed longitudinal axis of the underground continuous wall, erect a guide wall enclosure structure in the guide ditch, cast reinforced concrete guide wall, and set up a steel cage processing platform and equipment operation platform at the designated location on the construction site; Mud preparation and management: a mud pool is set up at the construction site. The mud pool includes a mixing pool, a slurry storage pool, a sedimentation pool and a waste slurry pool. The mixing pool is used to make fresh mud. The slurry storage pool is used to store fresh mud. The sedimentation pool is used to collect mud discharged from the tank section. The mixing pool, slurry storage pool and sedimentation pool are connected by a mud pump and a pipeline. The mud pump includes a mud input pump and a mud output pump. The mud input pump is used to input the mud in the slurry storage pool into the tank section, and the mud output pump is used to discharge the mud in the tank section outward. During the trenching construction, a trenching machine is used to construct 2 to 3 initial trench sections arranged at intervals based on the guide wall, and then the intermediate trench sections are constructed between the initial trench sections. Finally, the closed trench section is constructed to connect the initial trench section or the intermediate trench section. During the construction of the trenching machine, the mud input pump continuously injects fresh mud into the trench hole, and the mud output pump continuously discharges the mud at the bottom of the trench section. Clean the sediment and replace the slurry. After the trench section is dug to the designed depth and accepted, use the mud output pump to clean the sediment at the bottom of the trench section, and at the same time, continuously add fresh mud to the trench; Put down the joint pipe, first clean the mud and impurities adsorbed on the surface of the joint pipe by brushing, then place the joint pipe at the end of the trough section, and vertically hang it to the bottom of the trough. After placing the joint pipe, clean the sludge from the trough section; Lower the steel cage. Use the lifting equipment to place the steel cage made on the steel cage processing platform between the two joint pipes at the end of the trough, and vertically lift it to the bottom of the trough. When the steel cage is inserted into the trough to the designed elevation, use the channel steel to penetrate the cage and place it on the guide wall. After placing the steel cage, clean the sludge from the trough section. Insert the conduit, use the lifting equipment to hoist the conduit into the set position of the steel cage, and install the funnel on the top of the conduit; Underwater concrete pouring: concrete pouring should be carried out within 4 hours after the steel cage is placed in place. When the first batch of concrete is poured, the concrete is pressurized so that the concrete has impact energy, which will impact the bottom sediment to the top of the concrete. Pull out the joint pipe: 3 to 4 hours after pouring concrete, use a pipe pulling machine to move the joint pipe upward at set intervals. The moving distance is 5 to 10 cm, and the joint pipe must be pulled out before the concrete begins to set.

[0007] By adopting the above technical scheme, through accurate measurement of the construction site and marking of the guide wall outline, the construction position of the underground continuous wall is ensured to be accurate and the construction accuracy is improved. Specifically, a steel cage processing platform and an equipment operation platform are set at the set position of the construction site, which not only facilitates the operation of the construction equipment, but also improves the safety and convenience of the construction; the mud made of bentonite or high molecular polymer materials can effectively stabilize the groove wall and prevent collapse. At the same time, fresh mud is continuously injected into the groove hole and old mud is discharged through the mud pump, which ensures the mud quality in the groove hole and improves the reliability of construction; the starting groove section is arranged at intervals and the intermediate groove section and the closed groove section are gradually constructed to ensure the continuity and stability of the groove section and reduce the risks in construction; the sediment at the bottom of the groove section is thoroughly cleaned by the groove forming machine, and fresh mud is continuously added during the cleaning process to ensure the cleanliness of the bottom of the groove section and improve the concrete The quality of pouring; the surface of the joint pipe is brushed and cleaned to ensure the cleanliness of the joint pipe, avoid mud trapped at the joint, and improve the overall quality of the underground continuous wall; after the steel cage processing platform is completed, it is safely and accurately hoisted to the bottom of the trench by lifting equipment, ensuring the verticality and flatness of the steel cage, and improving the safety and efficiency of construction; the conduit is accurately hoisted into the set position of the steel cage by lifting equipment, and a square funnel is installed to ensure the stability of the conduit and the sealing of the top of the conduit, and improve the smoothness of concrete pouring; after the steel cage is sunk into place, concrete is poured in time, and the concrete is given impact energy by pressurization, which impacts the bottom sediment to the top of the concrete, ensuring the quality and continuity of concrete pouring; 3 to 4 hours after pouring concrete, the joint pipe is regularly moved by a pipe pulling machine to ensure the smooth removal of the joint pipe, avoid jamming and damage of the joint pipe, and improve the reliability and safety of construction.

[0008] Optionally, during trench construction, during the construction phase of the initial trench section, the middle trench section and the closed trench section, slot holes arranged at intervals are first dug in the trench section, and then the remaining partition walls between adjacent slot holes are removed.

[0009] By adopting the above technical scheme, the construction efficiency and quality can be effectively improved during the trenching construction process, wherein, by first digging slot holes arranged at intervals and then removing the partition walls between adjacent slot holes, the interference between the slot holes is reduced, the working efficiency of the trenching machine is improved, and the construction progress is accelerated; the slot holes arranged at intervals can make the grab bucket bear the force more evenly when eating soil, which helps to maintain the verticality of the trench wall, reduce the risk of trench wall collapse, and ensure the quality of trenching; first digging slot holes arranged at intervals and then removing the partition walls can reduce the overall instability and collapse risk of the trench wall to a certain extent, and improve the safety of construction; in the process of digging the slot holes at intervals, the stability and cleanliness of the mud in the slot hole can be maintained by continuously adding fresh mud and discharging old mud, and the stability of the trench wall and the construction quality can be further guaranteed.

[0010] Optionally, during trenching construction, the vertical accuracy of the trench wall shall not be less than 1 / 300, and the deviation of the center lines of two adjacent trench sections at the joint shall not be greater than 30 mm at any depth.

[0011] By adopting the above technical solution, the vertical accuracy of the trench wall during trenching construction is not less than 1 / 300, and the deviation of the center line of two adjacent trench sections at the joint at any depth is no more than 30mm, which can significantly improve the construction quality and stability of the underground continuous wall. Specifically, high vertical accuracy and small deviation value can effectively prevent the trench wall from collapsing during the construction process, ensure the verticality and flatness of the trench, and thus improve the structural safety and durability of the entire underground continuous wall. In addition, this high-precision control can also reduce the accumulation of errors in subsequent construction, ensure the tight connection between each trench section, and enhance the anti-seepage and anti-bending properties of the overall structure.

[0012] Optionally, the inlet end of the mud output pump is connected to a guide pipe, and the guide pipe is fixed on a guide mechanism, and the guide mechanism includes a gravity seat, a fixed seat and a pull rope, a through hole is provided in the middle of the fixed seat for the guide pipe to pass through, and a power seat plate is provided above; a limiting hole is provided in the middle of the power seat plate, a reel is provided at the upper end, and a first pulley group and a second pulley group are provided at the lower end; the through hole is evenly distributed with at least three guide holes in the circumference; one end of the pull rope is fixed on the reel after passing through the first pulley group, the second pulley group and the limiting hole in sequence, and the other end passes through the guide hole and is connected to the gravity seat; a diversion hole is provided in the middle of the gravity seat, and a protective rope is provided between the gravity seat and the fixed seat, and retaining rings are arranged at intervals on the protective rope, wherein the fixed seat is fixed on the mobile device.

[0013] By adopting the above technical scheme, the guide pipe can be conveniently moved, and the cleaning and discharge of the sediment at the bottom of the trough section can be convenient, wherein the gravity seat is used to connect the suction end of the guide pipe, and the guide hole can be a trumpet-shaped structure, which has a certain weight, and can reduce the impact of strong winds or human touch on the pull rope, reduce the shaking of the guide pipe in the trough section, and reduce the collision with the trough section wall. The retaining ring on the protective rope can further limit the guide pipe to a certain space to prevent it from colliding with the trough section wall. During the construction process, the mobile equipment can be a specially designed mobile cart, which needs to move slowly during the movement to avoid large shaking of the gravity seat due to inertia.

[0014] Optionally, during sediment removal and slurry replacement, if there is a height difference at the bottom of the tank section, the gravity seat is pushed from the high end to the low end.

[0015] By adopting the above technical solution, the trenching machine can more efficiently remove sediments when cleaning the sediment at the bottom of the trench section, ensuring the flatness and cleanliness of the trench bottom. Especially when there is a height difference at the bottom of the trench section, the method of pushing the gravity seat from the high end to the low end helps to reduce the accumulation of sediment and improve the cleaning effect, thereby ensuring the construction quality of the underground continuous wall and the smooth progress of the subsequent concrete pouring.

[0016] Optionally, the mud pool includes a stirring pool, a slurry storage pool, a sedimentation pool and a waste slurry pool; the stirring pool is used to make fresh mud; the slurry storage pool is used to store fresh mud; and the sedimentation pool is used to collect mud discharged from the tank section.

[0017] By adopting the above technical solution, the mud pool is divided into a mixing pool, a slurry storage pool, a sedimentation pool and a waste slurry pool, realizing classified management and efficient recycling of mud. The mixing pool is specially used to make fresh mud to ensure the quality and performance of mud; the slurry storage pool is used to store fresh mud to ensure the continuity and stability of mud supply; the sedimentation tank is used to collect mud discharged from the trough section. After sedimentation treatment, most impurities and solid particles are removed to reduce mud pollution. This classified management method not only improves the utilization rate of mud and reduces waste, but also effectively reduces environmental pollution and improves construction efficiency and quality.

[0018] Optionally, the sedimentation tank is connected to a mud purifier, and the mud purifier filters the sand in the mud and returns it to the sedimentation tank, and the performance of the mud in the sedimentation tank is tested.

[0019] By adopting the above technical scheme, effective recycling of mud can be achieved, the utilization rate of mud is improved, and environmental pollution is reduced. Among them, the sedimentation tank is connected with the mud purifier, which can filter out the sand in the mud to form regenerated mud. The regenerated mud can be returned to the slurry storage tank for use again, which greatly improves the utilization rate of mud and reduces the consumption cost of mud; by purifying the mud, the impact of mud discharge on the environment is reduced, and the environmental protection risk in the construction process is reduced; the use of mud purifier makes mud treatment more efficient, reduces the time and labor cost of mud treatment, and improves the efficiency of the entire construction process; the mud that has been purified is of higher quality, which helps to ensure the quality of trench construction, especially the stability and verticality of the trench wall, and further improves the overall construction quality of the underground continuous wall.

[0020] Optionally, during sediment cleaning, the mud output pump is connected to a mud purifier, and the mud treated by the mud purifier is returned to the trough section. When the slag outlet of the purifier no longer screens out sand particles, the mud treated by the mud purifier is returned to the sedimentation tank.

[0021] By adopting the above technical scheme, during the process of clearing sediment and replacing slurry, the mud purifier can be directly used to effectively separate and purify the mud, remove sand and other impurities in the mud, ensure the cleanliness of the mud, improve the efficiency of slag removal, and timely judge the content status of impurities in the mud and accurately control the slag removal time. This not only improves the reuse rate of the mud and reduces the waste of mud, but also effectively prevents impurities in the mud from adversely affecting the quality of the underground continuous wall, ensuring the thoroughness and efficiency of the sediment removal work at the bottom of the trench.

[0022] Optionally, during underwater concrete pouring, double conduits are used for injection, and the rising speed of the concrete surface in the trench is less than 3m / h during pouring; the depth of the conduit concrete buried in the concrete should be 2m to 4m, and the height difference of the concrete in two adjacent conduits should be less than 0.5m.

[0023] By adopting the above technical scheme, the quality and efficiency of the underwater concrete pouring process are ensured. Specifically, the double-duct injection method can ensure that the concrete is evenly distributed in the trough, avoiding the problem of local over-concentration or over-thinness that may be caused by a single duct. At the same time, the rising speed of the concrete surface in the trough is controlled to be less than 3m / h, which ensures the continuity and uniformity of concrete pouring, reduces the formation of bubbles and voids, and improves the density and strength of the concrete; the duct concrete is buried in the concrete at a depth of 2m to 4m, which not only helps to reduce the segregation of concrete, but also ensures good contact between the duct and the concrete, further improving the pouring quality of the concrete. In addition, the height difference of the concrete in the two adjacent ducts is controlled to be less than 0.5m, which ensures uniform concrete pouring in the entire trough section and avoids the problem of poor concrete flow or local accumulation due to excessive height difference. These measures work together to significantly improve the overall quality and construction efficiency of the underground continuous wall.

[0024] Optionally, a positioning plate is provided in the steel cage; a bent protrusion is provided in the middle of the positioning plate and is welded to the main reinforcement of the steel cage.

[0025] By adopting the above technical solution, a positioning plate is arranged in the steel cage, and a bending protrusion is provided in the middle of the positioning plate and welded to the main reinforcement of the steel cage, which can effectively improve the overall rigidity and stability of the steel cage, prevent deformation during lifting and lowering, and ensure that the steel cage is accurately positioned; at the same time, the design of the bending protrusion can better disperse stress, enhance the bond strength between the steel cage and concrete, and improve the overall quality and durability of the underground continuous wall.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. This construction method ensures the verticality and flatness of the trench wall through the reasonable selection of trenching machines and the optimization of construction technology, especially the use of hydraulic grab trenching machines, and real-time monitoring and correction during the construction process, effectively reducing the risk of trench wall collapse and improving trenching accuracy; 2. This construction method ensures that the height of the mud level in the tank and the mud performance indicators meet the design requirements through scientific management and efficient circulation of the mud system, enhances the mud wall protection effect, reduces mud loss, and reduces construction costs; 3. This construction method ensures the manufacturing accuracy and hoisting stability of the steel cage through the precise setting of the steel cage manufacturing platform and the reasonable selection of hoisting equipment, avoids the deformation of the steel cage during the hoisting process, and improves the overall quality of the underground continuous wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of an underground continuous wall construction method in an embodiment; Figure 2 is a schematic diagram of the mud system processing in the embodiment; Figure 3 is a structural schematic diagram of a guide wall in an embodiment; Figure 4 is a structural schematic diagram of the guide mechanism in the embodiment; Figure 5 is a schematic diagram of a partial structure of a guide mechanism in an embodiment; Figure 6 is a schematic structural diagram of a power seat plate in an embodiment; Figure 7 is a schematic diagram of the structure of the joint pipe in the embodiment; Figure 8 Schematic diagram of the structure of the positioning plate in the embodiment.

[0028] In the figure: 1. guide wall; 2. guide pipe; 3. gravity seat; 31. diversion hole; 32. lifting cover; 33. positioning rod; 4. fixing seat; 41. through hole; 42. guide hole; 43. power seat plate; 44. first pulley block; 45. second pulley block; 46. limiting hole; 5. pull rope; 6. protective rope; 7. retaining ring; 8. reel; 81. motor; 9. positioning plate; 91. bending protrusion; 10. joint pipe; 11. moving equipment. DETAILED DESCRIPTION

[0029] The following will be combined with the attached Figures 1 to 8 As shown, the technical solutions of the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0030] The present application embodiment discloses a method for constructing an underground continuous wall. Figures 1 to 3 As shown, the following steps are included: Measure and lay out, measure the construction site, lay out along the longitudinal axis of the underground continuous wall design, and mark the outline of the guide wall 1 retaining structure design on both sides of the longitudinal axis of the continuous wall design; to ensure the design thickness of the side wall of the main structure, the outline of the retaining structure design is set outward according to the design requirements, with a setting amount of 5 cm; this step ensures the accuracy and reliability of the construction and lays the foundation for subsequent construction.

[0031] Guide wall 1, construction platform construction, excavate the guide ditch along the designed longitudinal axis of the underground continuous wall, set up the guide wall 1 enclosure structure in the guide ditch, and cast the reinforced concrete guide wall 1, set up the steel cage processing platform and the equipment operation platform at the set position of the construction site, among which, Figure 3 As shown, the guide wall 1 adopts a "┓┏" type integral reinforced concrete structure. The inner net width of the guide wall 1 is 5cm larger than the designed thickness of the continuous wall. The guide wall 1 is 20cm thick and 1.5m deep, and is cast with C25 reinforced concrete. The construction form of the guide wall 1 ensures the stability of the trench wall and reduces the impact of the dynamic load on the trench wall during the construction process. The diagonal size of the steel cage processing platform needs to be checked when it is erected, and the elevation of the platform is adjusted with a level when the platform is fixed to ensure the flatness. The channel steel on the platform is marked with paint according to the designed steel bar spacing and position to ensure the accuracy of the layout and binding of the steel bars. In order to ensure the construction period, trenching operations can be carried out during the day and on rainy days when the trenching soil is difficult to transport. A soil storage area that can accommodate 400m³ of trenching soil is set up in the construction area for temporary storage of trenching wet soil.

[0032] Mud preparation and management, such as Figure 1~2 As shown, a mud pool is set up at the construction site, and the mud mixing material is bentonite or high molecular polymer material, wherein the mud pool includes a mixing pool, a slurry storage pool, a sedimentation pool and a waste slurry pool, the mixing pool is used to make fresh mud, the slurry storage pool is used to store fresh mud, and the sedimentation pool is used to collect mud discharged from the tank section, and the pools can be connected by a mud pump and a conduit to form a mud circulation pipeline; the newly mixed mud should be stored for more than 24 hours to allow the bentonite to be fully hydrated before use; and the reserve amount of mud is considered to be 1.5 to 2 times the volume of the maximum unit tank section; this step ensures that the performance indicators of the mud meet the design requirements and improves the stability of the tank wall. Specifically, the mud pump includes a mud output pump and a mud input pump, the mud input pump is used to inject fresh mud into the tank section, and the mud output pump is used to discharge the mud in the tank section.

[0033] In trenching construction, a trenching machine is used with the guide wall 1 as the reference to first construct 2 to 3 starting trench sections arranged at intervals, then construct intermediate trench sections between the starting trench sections, and finally construct a closed trench section to connect the starting trench section or the intermediate trench section. During the construction of the trenching machine, the mud input pump continuously injects fresh mud into the trench hole, and the mud output pump continuously discharges the mud at the bottom of the trench hole outward. Specifically, the trenching machine is a grab trenching machine, and the model can be an SG-35A hydraulic grab trenching machine. The modified trenching machine is equipped with a verticality display instrument and a correction device, and the deviation can be corrected in time during the trenching process. When excavating solid soil, the bucket teeth on both sides of the trenching machine grab are in the soil eating state at the same time, so that the grab digs the trench under the state of balanced soil eating resistance. In terms of quality control, the vertical accuracy of the trench wall shall not be less than 1 / 300, and the deviation of the center line of the two adjacent trench sections at the joint at any depth shall not be greater than 30mm. When detecting the deviation, the trench section plane position deviation detection: the trench section is measured with a measuring hammer The position of the two ends, the deviation between the measured position lines at the two ends and the dividing line of the slot section is the plane position deviation of the slot section; the slot section depth detection, use a hammer to measure the slot bottom depth at the left, middle and right positions of the slot section, and the average depth of the three positions is the depth of the slot section; this step ensures the accuracy and stability of the slot and reduces the risk of slot wall collapse; further, in order to enable the grab bucket to work evenly when digging a single hole, effectively correct the deviation, and ensure the verticality of the slot, in the construction stage of the starting slot section, the middle slot section and the closed slot section, first dig slot holes arranged at intervals in the slot section, and then remove the remaining partition walls between adjacent slot holes. After the single hole and the hole partition wall are dug to the designed depth, dig several buckets along the length of the slot, and repair and smooth the concave and convex surfaces formed by the different verticalities of the grab bucket when digging the single hole and the partition wall, so as to ensure that the slot section has good horizontal linearity; while the grab bucket is digging along the length of the slot, the grab bucket is lowered to the designed depth of the slot section to remove the sediment at the bottom of the slot.

[0034] Clean the sediment and change the slurry, such as Figure 1~2 As shown in the figure, after the trench section is dug to the designed depth and accepted, the sediment at the bottom of the trench section is cleaned with a mud output pump, and fresh mud is continuously added to the trench during cleaning. The amount of fresh mud added is adjusted until the performance indicators of the mud in the trench meet the design standards. The qualified standards for hole cleaning and slurry replacement are: the thickness of siltation at the bottom of the hole ≤10cm; the density of the mud in the hole ≤1.15g / cm3; the viscosity is 32~50s; the sand content is ≤6%.

[0035] like Figures 4 to 6As shown, in order to facilitate the cleaning of the bottom of the groove section, the inlet end of the mud output pump is connected with a guide pipe 2, and the guide pipe 2 is fixed on the guide mechanism, and the guide mechanism includes a gravity seat 3, a fixed seat 4 and a pull rope 5; the middle part of the fixed seat 4 is provided with a through hole 41 for the guide pipe 2 to pass through, and a power seat plate 43 is provided above; a limiting hole 46 is provided in the middle of the power seat plate 43, a reel 8 is provided at the upper end, and a first pulley group 44 and a second pulley group 45 are provided at the lower end along the circumference of the limiting hole 46; the first pulley group 44 is located on the outside of the second pulley group 45; the through hole 41 is circumferentially There are three guide holes 42; the guide holes 42 correspond to the pulley blocks; one end of the pull rope 5 passes through the first pulley block 44, the second pulley block 45 and the limiting hole 46 in sequence and is fixed on the reel 8, and the other end passes through the guide hole 42 and is connected to the gravity seat 3; the gravity seat 3 is used to connect with the guide pipe 2, and a diversion hole 31 is provided in the middle, and a protective rope 6 is provided between the gravity seat 3 and the fixed seat 4, and a retaining ring 7 is arranged at intervals on the protective rope 6. In order to limit the position of the retaining ring 7, four positioning rods 33 are evenly distributed on the upper end surface of the gravity seat 3 in the circumferential direction, wherein the reel 8 is driven by a motor 81 The guide hole 31 can be a trumpet-shaped structure to expand the suction area. The bottom of the gravity seat 3 can be provided with a lifting cover 32, which is used to lift the gravity seat 3 so that the guide hole 42 and the bottom of the groove maintain a certain space, which is convenient for the suction of sediment. The fixed seat 4 is fixed on the mobile device 11. The mobile device 11 can be a dedicated mobile trolley. It needs to move slowly during the movement to avoid the gravity seat 3 from shaking greatly due to inertia. When working, the guide hole 42 of the gravity seat 3 forms a negative pressure to suck the sediment at the bottom of the groove into the guide hole 42. The mud is discharged from pipe 2 by the mud output pump and enters the mud purifier for treatment; the mud output pump is connected to the mud purifier, and the mud treated by the mud purifier returns to the trough section. When the slag outlet of the mud purifier no longer screens out sand particles, the sludge cleaning work at the bottom of the trough is completed, and the mud treated by the mud purifier returns to the sedimentation tank. This step ensures the cleanliness of the bottom of the trough section and improves the quality of concrete pouring; the mud returned to the sedimentation tank is transported to the mixing tank after the mud performance test, and is prepared into regenerated mud after adding ingredients in the mixing tank and transported to the slurry storage tank.

[0036] Lower joint pipe 10, such as Figure 7 As shown, the joint pipe 10 adopts the form of a circular locking pipe joint. Before construction, the mud skin and impurities adsorbed on the surface of the joint pipe 10 are first cleaned by brushing the wall, and then the joint pipe 10 is placed at the end of the groove section and vertically hung to the bottom of the groove. After the joint pipe 10 is placed, the groove section is cleaned of sediment; this step ensures the construction quality of the joint and avoids the quality defect of mud stuck in the joint.

[0037] Lower the steel cage, place the steel cage made on the steel cage processing platform between the two joint pipes 10 at the slot end by using the lifting equipment, and vertically lift it to the bottom of the slot, and when the steel cage is inserted into the slot to the designed elevation, insert the channel steel into the cage and place it on the guide wall 1, calibrate the lower position and the lower elevation, and then fix its position; after placing the steel cage, clear the sediment from the slot; among them, if Figure 8 As shown, a positioning plate 9 is provided in the steel cage, and a bending protrusion 91 is provided in the middle of the positioning plate 9, which is welded to the main reinforcement of the steel cage; this step ensures the stability and accuracy of the steel cage and improves the overall performance of the underground continuous wall.

[0038] Insert the conduit, and use the lifting equipment to hoist the conduit into the set position of the steel cage. Install a square funnel on the top of the conduit. The conduit uses a Φ250mm steel pipe, and the inner wall should be smooth, round, and have the same inner diameter. The length of the conduit section is 3.0m long for the middle section and 2.5m for the bottom section. A 1m long conduit is used under the funnel, and the joint is sealed and waterproof with a rubber ring. After the conduit is assembled, the axis deviation shall not exceed 0.5% of the drilling depth and shall not exceed 10cm. When connected, the connecting bolts and nuts are on top, and the test pressure is 1.5 times the hydrostatic pressure at the bottom of the hole. The length of the conduit is determined by the hole depth and the height of the working platform. The distance between the bottom of the funnel and the upper opening of the drilling hole is greater than the length of one middle section of the conduit. The conduit joint flange is added with a conical loop, and there shall be no flange at the lower end of the bottom section conduit. If conditions permit, a spiral threaded joint can be used, but there must be a loosening prevention device. This step ensures the installation quality of the conduit and the smooth progress of concrete pouring.

[0039] For underwater concrete pouring, after the steel cage is sunk into place, the concrete should be poured in time, within 4 hours, and when the first batch of concrete is poured, the concrete should be pressurized so that the concrete has impact energy, which will impact the bottom sediment to the top of the concrete. Double conduits are used for injection, and the rising speed of the concrete surface in the trough is less than 3m / h during pouring; the depth of the conduit concrete buried in the concrete should be 2m to 4m, and the height difference of the concrete in two adjacent conduits should be less than 0.5m. During this construction process, a dedicated person will measure the buried depth of the conduit and the height difference of the concrete surface inside and outside the pipe, and fill in the underwater concrete pouring record in time; this step ensures the quality and efficiency of concrete pouring and improves the overall performance of the underground continuous wall.

[0040] Pull out the joint pipe 10. A hydraulic pipe pulling machine is used to pull out the joint pipe 10. After pouring concrete for 3 to 4 hours, the joint pipe 10 is moved upward by the pipe pulling machine at set time intervals. The moving distance is 5 to 10 cm, and all joint components are pulled out before the concrete begins to set.

[0041] The implementation principle of this embodiment is as follows: through a series of innovations and technical optimizations, the underground continuous wall construction is realized with high efficiency, accuracy and safety, among which, the measurement and setting out of lines and the guide wall 1, the construction platform building steps ensure the accuracy and reliability of the construction, and lay a solid foundation for the subsequent construction; the mud preparation and management step ensures that the performance indicators of the mud meet the design requirements and improves the stability of the trench wall through scientific mud management and efficient mud purification equipment; the trenching construction step ensures the accuracy and stability of the trenching through advanced trenching machines and optimized construction processes, and reduces the risk of trench wall collapse; the sediment cleaning and slurry replacement step ensures the cleanliness of the bottom of the trench section through efficient sediment cleaning and mud purification equipment, and improves the quality of concrete pouring; the lower joint pipe 10 step The step of installing the steel cage ensures the construction quality of the joints and avoids the quality defect of mud stuck in the joints through a strict joint pipe 10 pulling process; the step of lowering the steel cage ensures the stability and accuracy of the steel cage and improves the overall performance of the underground continuous wall through modular prefabricated steel cages and intelligent lifting equipment; the step of inserting the conduit ensures the installation quality of the conduit and the smooth progress of concrete pouring through scientific conduit installation technology and rigorous operating procedures; the step of underwater concrete pouring ensures the quality and safety of concrete pouring through advanced concrete pumping technology and intelligent monitoring system; in summary, the embodiments of the present application have significantly improved the efficiency and quality of underground continuous wall construction through a series of innovations and technical optimizations, and provided reliable technical support for large-scale infrastructure construction.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present application.

Claims

1. A method for constructing an underground continuous wall, characterized in that: The following steps are involved: Survey and set out: survey the construction site, set out along the longitudinal axis of the underground continuous wall design, and mark the guide wall (1) enclosure structure design contour edge line on both sides of the longitudinal axis of the continuous wall design; The guide wall (1) and the construction platform are constructed, a guide trench is excavated along the designed longitudinal axis of the underground continuous wall, a guide wall (1) enclosure structure is erected in the guide trench, and a reinforced concrete guide wall (1) is poured, and a steel cage processing platform and an equipment operation platform are set at a set position on the construction site; Mud preparation and management: a mud pool is set up at the construction site. The mud pool includes a mixing pool, a slurry storage pool, a sedimentation pool and a waste slurry pool. The mixing pool is used to make fresh mud. The slurry storage pool is used to store fresh mud. The sedimentation pool is used to collect mud discharged from the tank section. The mixing pool, slurry storage pool and sedimentation pool are connected by a mud pump and a pipeline. The mud pump includes a mud input pump and a mud output pump. The mud input pump is used to input the mud in the slurry storage pool into the tank section, and the mud output pump is used to discharge the mud in the tank section outward. During the trenching construction, a trenching machine is used to construct 2 to 3 initial trench sections arranged at intervals with the guide wall (1) as a reference, then an intermediate trench section is constructed between the initial trench sections, and finally a closing trench section is constructed to connect the initial trench sections or the intermediate trench sections. During the construction of the trenching machine, a mud input pump continuously injects fresh mud into the trench hole, and a mud output pump continuously discharges mud at the bottom of the trench section. Clean the sediment and replace the slurry. After the trench section is dug to the designed depth and accepted, use the mud output pump to clean the sediment at the bottom of the trench section, and at the same time, continuously add fresh mud to the trench; Lower the joint pipe, first clean the mud and impurities adsorbed on the surface of the joint pipe (10) by brushing the wall, then place the joint pipe (10) at the end of the trough section and vertically hang it to the bottom of the trough. After the joint pipe (10) is placed, clean the sludge from the trough section; Lower the steel cage, place the steel cage manufactured on the steel cage processing platform between the two joint pipes (10) at the ends of the trough using a lifting device, and vertically lift it to the bottom of the trough. When the steel cage is inserted into the trough to the designed elevation, insert the channel steel into the cage and place it on the guide wall (1). After the steel cage is placed, clear the sediment from the trough section; Insert the conduit, use the lifting equipment to hoist the conduit into the set position of the steel cage, and install the funnel on the top of the conduit; Underwater concrete pouring: concrete pouring should be carried out within 4 hours after the steel cage is placed in place. When the first batch of concrete is poured, the concrete is pressurized so that the concrete has impact energy, which will impact the bottom sediment to the top of the concrete. The joint pipe is pulled out. After pouring concrete for 3 to 4 hours, the joint pipe (10) is moved upward by a pipe pulling machine at set intervals. The moving distance is 5 to 10 cm, and the joint pipe (10) is pulled out before the concrete begins to set.

2. The underground continuous wall construction method according to claim 1, characterized in that: During trench construction, during the construction phase of the initial trench section, the middle trench section and the closed trench section, slot holes arranged at intervals are first dug in the trench section, and then the remaining partition walls between adjacent slot holes are removed.

3. The underground continuous wall construction method according to claim 1, characterized in that: During trenching construction, the vertical accuracy of the trench wall shall not be less than 1 / 300, and the deviation of the center line of two adjacent trench sections at the joint shall not be greater than 30mm at any depth.

4. The underground continuous wall construction method according to claim 1, characterized in that: The inlet end of the mud output pump is connected to a guide pipe (2), the guide pipe (2) is fixed on a guide mechanism, the guide mechanism comprises a gravity seat (3), a fixed seat (4) and a pull rope (5), a through hole (41) for the guide pipe (2) to pass through is provided in the middle of the fixed seat (4), and a power seat plate (43) is provided above; a limiting hole (46) is provided in the middle of the power seat plate (43), a reel (8) is provided at the upper end, and a first pulley group (44) and a second pulley group (45) are provided at the lower end; the through hole (41) is circumferentially At least three guide holes (42) are evenly distributed; one end of the pull rope (5) passes through the first pulley group (44), the second pulley group (45) and the limit hole (46) in sequence and is fixed on the reel (8), and the other end passes through the guide hole (42) and is connected to the gravity seat (3); a guide hole (31) is provided in the middle of the gravity seat (3), and a protective rope (6) is provided between the gravity seat (3) and the fixed seat (4), and the protective rope (6) is arranged with retaining rings (7) at intervals, wherein the fixed seat (4) is fixed on the mobile device (11).

5. The underground continuous wall construction method according to claim 4, characterized in that: During the process of clearing sediment and replacing slurry, if there is a height difference at the bottom of the tank section, the gravity seat (3) is pushed from the high end to the low end.

6. The underground continuous wall construction method according to claim 1, characterized in that: The mud pool includes a stirring pool, a slurry storage pool, a sedimentation pool and a waste slurry pool; the stirring pool is used to make fresh mud; the slurry storage pool is used to store fresh mud; and the sedimentation pool is used to collect mud discharged from the tank section.

7. The underground continuous wall construction method according to claim 6, characterized in that: The sedimentation tank is connected with a mud purifier, and the mud purifier filters the sand in the mud and returns it to the sedimentation tank, and the performance of the mud in the sedimentation tank is tested.

8. The underground continuous wall construction method according to claim 6, characterized in that: During sediment cleaning, the mud output pump is connected to the mud purifier, and the mud treated by the mud purifier is returned to the trough section. When the slag outlet of the purifier no longer screens out sand particles, the mud treated by the mud purifier is returned to the sedimentation tank.

9. The underground continuous wall construction method according to claim 1, characterized in that: In underwater concrete pouring, double conduits are used for injection. During pouring, the rising speed of the concrete surface in the trench is less than 3m / h; the depth of conduit concrete buried in concrete should be 2m to 4m, and the height difference of concrete in two adjacent conduits should be less than 0.5m.

10. The underground continuous wall construction method according to claim 1, characterized in that: A positioning plate (9) is provided in the steel cage; a bent protrusion (91) is provided in the middle of the positioning plate (9) and is welded to the main reinforcement of the steel cage.

Images