Underground excavation obstacle removing scaffold used for being tightly attached to underground diaphragm wall of existing station and construction method

Abstract

The invention relates to the technical field of underground excavation construction, in particular to an underground excavation obstacle removing scaffold tightly attached to an underground diaphragm wall of an existing station and a construction method.The underground excavation obstacle removing scaffold comprises a frame body, two walkway plates are installed on the upper portion of the frame body, a dense mesh is arranged on the front side of the frame body, and two installation grooves are formed in the left side and the right side of each walkway plate; a mounting block is inserted into the inner wall of the mounting groove, and sliding blocks are mounted on the front side and the rear side of the mounting block; the method has the beneficial effects that the MJS horizontal reinforcing technology and the five-step three-step method are adopted for tunnel portal breaking, rapid, safe and low-cost tunnel portal breaking work is achieved, the construction progress is accelerated, the construction risk is reduced, meanwhile, in the scaffold erecting process, through cooperation of a hook, a lower hook piece and a rubber pad, the construction efficiency is improved, and the construction cost is reduced. Therefore, the possibility that the walkway plate slides on the frame body is effectively reduced, the installation stability of the walkway plate is enhanced, and the using effect of the scaffold can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground dark excavation construction, in particular to a dark excavation obstacle-clearing scaffold and a construction method for being close to an underground continuous wall of an existing station. Background Art

[0002] As a key livelihood project, urban rail transit construction plays an extremely important role in promoting high-quality development in many aspects of urban operation, management and services. In order to build a developed regional rail transit network, it is urgently necessary to carry out rail transit expansion projects under complex and restricted conditions in the urban core area. Under such conditions, the newly built tunnel section will inevitably pass through the existing line structure closely. Usually, existing stations will reserve through-passages for future lines, but in actual projects, due to planning deficiencies, some reserved passages cannot be used, which leads to obstacles such as retaining piles, pull-out piles and lattice columns in the foundations of existing stations. Obstacles hinder the normal advancement of the shield machine. In order to ensure that the shield section can safely pass under the operating subway station, it is necessary to conduct research and analysis on the removal of obstacles around the foundation of the existing station.

[0003] In view of the high risks and complexity of construction technology brought about by dismantling underground continuous walls and excavating sandwich soil close to operating stations, and taking into account the problem of walkway plates sliding when temporarily setting up scaffolding, the present invention conducts in-depth research on the dark excavation and obstacle clearance process close to the underground continuous walls of existing stations, and proposes a dark excavation and obstacle clearance scaffolding and construction method for close to the underground continuous walls of existing stations to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a scaffolding and construction method for dark excavation and obstacle removal close to the underground continuous wall of an existing station, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a scaffold for dark excavation and obstacle removal close to the underground continuous wall of an existing station, comprising a frame, two walkway plates are installed on the upper part of the frame, a dense mesh is arranged on the front side of the frame, two installation grooves are provided on the left and right sides of the walkway plates, installation blocks are inserted into the inner walls of the installation grooves, sliders are installed on the front and rear sides of the installation blocks, hooks are installed on the separated sides of the installation blocks on the left and right sides, a movable groove is provided inside the hook, a pushing block is inserted into the inner wall of the movable groove, and the pushing block A fixing plate is installed on the outer side of the block, an insert block is arranged on the top of the push block, a slide groove 1 is provided on the inner upper side of the mounting block, a limit block is installed on the inner wall of the slide groove 1, springs are installed on the adjacent sides of the limit blocks on the left and right sides, a gear is rotatably connected to the inner wall of the mounting block, a slide groove 2 is provided on the bottom of the mounting block, a lower hook is inserted on the inner wall of the slide groove 2, rubber pads are installed on the separated sides of the lower hooks on the left and right sides, a limit groove is provided on the adjacent sides of the slide grooves 2 on the left and right sides, and a connecting plate is installed on the inner wall of the limit groove;

[0006] The adjacent sides of the plug blocks on the left and right sides are penetrated by hooks and inserted into the inner wall of the mounting block, the bottom of the plug block is meshed with the gear, the separated sides of the lower hooks on the left and right sides are meshed with the gears, and the adjacent sides are installed between the connecting plates, the fixed plate is slidably connected to the inner wall of the second slide groove, the bottom of the push block is attached to the surface of the frame, the separated sides of the rubber pads on the left and right sides are attached to the surface of the frame, the slider is inserted into the inner wall of the mounting groove, and the adjacent ends of the springs on the left and right sides are installed on the inner wall of the first slide groove.

[0007] Preferably, one of the magnets 1 is installed at the bottom of the lower hook, and another magnet 1 is installed on the separated sides of the hooks on the left and right sides, a slide groove 3 is opened inside the hook, an elastic metal plate is inserted into the inner wall of the slide groove 3, a pull cloth is installed at the bottom of the elastic metal plate, and magnets 2 are installed on the adjacent sides of the pull cloths on the left and right sides;

[0008] The adjacent sides of the elastic metal plates on the left and right sides are both plugged into the bottom of the lower hook, the second magnet is fitted with the middle magnet one, and the elastic metal plates are fitted on the surface of the frame.

[0009] Preferably, the hooks on the left and right sides are provided with placement grooves on their separated sides, the placement grooves on the left and right sides are hinged with rubber cover plates on their adjacent sides, the bottom wall of the placement grooves is provided with a plurality of mounting rings, and the outer sides of the plurality of mounting rings are provided with fixing ropes;

[0010] The two fixing ropes on the front side are both installed between the dense mesh, and the two ends of the fixing ropes are respectively installed between the installation rings;

[0011] Two clamping grooves are provided on both sides of the inner wall of the installation groove, a sliding groove 4 is provided inside the slider, a moving block is installed on the inner wall of the sliding groove 4, and clamping blocks are installed on the separated sides of the moving blocks on the front and rear sides, and an elastic member is provided on the inner wall of the sliding groove 4;

[0012] The elastic member is fitted with the moving block, and the clamping blocks on the left and right sides both penetrate the slider and are respectively fitted between the clamping grooves on the two sides.

[0013] A construction method for dark excavation and obstacle removal close to an existing underground continuous wall of a station, comprising a dark excavation and obstacle removal scaffold close to an existing underground continuous wall of a station, the method comprising the following steps:

[0014] S1: Carry out MJS horizontal reinforcement under the operating station to reduce the impact of subsequent construction on the operating station;

[0015] S2: A scaffold is set up at the bottom of the obstacle clearance shaft. The scaffold consists of multiple frames, and two walkway boards are set up on the upper part of the frame. At the same time, a dense mesh is arranged on the front side of the frame;

[0016] S3: Horizontal drilling is used to check the reinforcement effect of the soil in front, and grouting reinforcement is carried out if there is water leakage;

[0017] S4: The tunnel door is chiseled out, and the underground continuous wall of the obstacle clearance shaft is broken down layer by layer from top to bottom;

[0018] S5: Following the order of tunnel gate removal, excavate the obstacle clearance well and the sandwich soil between the operating stations in layers and blocks, and carry out initial support;

[0019] S6: Gradually demolish underground continuous walls of operating stations;

[0020] S7: Backfilling of the underground excavation section.

[0021] Preferably, in S1, φ2400mmMJS semicircular horizontal reinforcement is used below the operating station structure floor, with a vertical spacing of 800mm and a horizontal spacing of 1800mm, and the piles are constructed layer by layer from bottom to top and from both sides to the middle.

[0022] Preferably, in S2, the ground-to-ground diagonal braces of the scaffold are connected with steel pipes to limit the aspect ratio, or act on the stable structure, walkway boards are laid on each platform, stairs are set between the upper and lower layers, and enclosures about 1.2 meters high are set on the edges, and dense mesh and safety warning signs are hung as required;

[0023] In S2, the angle between the scaffolding support and the ground is not greater than 60°. Considering the limitation of the erection space, the position of the top of the support is changed, and at the same time, the upper, middle and lower positions on both sides are connected to the main reinforcement of the ground-connected wall or the shield steel ring to form a wall connection member, thereby improving the overall stability of the entire frame.

[0024] Preferably, in S3, the exploration holes are distributed at the edge and center of the ruptured portion.

[0025] Preferably, in S4, the tunnel door is manually removed in stages from top to bottom and from both sides to the middle, and the grid steel frame is installed and concrete is sprayed immediately after the removal is completed.

[0026] Preferably, in S5, the interlayer soil excavation between the clearance shaft ground wall and the operating station ground wall is 50 cm in scale, and is gradually excavated from top to bottom and from both sides to the middle. After the soil is removed in layers, 4 cm of concrete is sprayed on the upper end of the hole and grid steel bars are installed.

[0027] Preferably, in S6, after the ground wall and sandwich soil of the obstacle clearance work pit are excavated and the initial support is completed, the ground wall of the operating station is demolished;

[0028] In the above S6, 300mm of the ground wall of the operating station is reserved. A temporary scaffold is first set up to break the front ground wall. After the breaking is completed, the temporary scaffold is removed, and then the remaining 300mm thick ground wall is broken layer by layer from bottom to top. The breaking height is controlled at 1000-1100mm each time. One layer is broken and backfilled. When the backfill strength below meets the conditions of the construction station personnel, the next layer is broken and backfilled. Repeat the operation until the ground wall of the tunnel gate is broken;

[0029] In S7, the dark excavation section is backfilled with C15 plain concrete to the outer facade of the main inner lining wall of the operating station, and the side tunnel door of the obstacle clearance shaft is backfilled with M5 mortar, and the backfill range is the dark excavation section and the entire foundation pit.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The construction method for dark excavation and obstacle removal close to the underground continuous wall of the existing station proposed by the present invention effectively prevents the instability damage of water and soil after losing support and protection by adopting the MJS horizontal reinforcement technology, avoids the large-scale surface collapse and cracking damage that may occur in the soil body inside the tunnel portal, and significantly improves the construction safety. At the same time, the five-step three-step method is adopted to break the tunnel portal, optimizes the excavation sequence, reduces the influence of mechanical vibration load, and effectively controls the deformation of the existing structure, thereby more safely ensuring the normal operation of underground and surface buildings, and realizing fast, safe and low-cost tunnel portal breaking work, which not only speeds up the construction progress, but also reduces the construction risk, and has significant economic and social benefits.

[0032] At the same time, in the process of erecting the scaffolding, the hooks, lower hooks and rubber pads are used in coordination with each other, thereby effectively reducing the possibility of the walkway board sliding on the frame, thereby enhancing the stability of the walkway board installation and improving the use effect of the scaffolding. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of the MJS method pile horizontal reinforcement construction method of the present invention;

[0034] Figure 2 This is a schematic diagram of the dark excavation area of ​​the present invention;

[0035] Figure 3 This is a schematic diagram of the scaffolding erection of the present invention;

[0036] Figure 4 This is a schematic diagram of the horizontal reinforcement of MJS and the exploration hole of the tunnel portal of the present invention;

[0037] Figure 5 It is a plan elevation view of the side dark excavation of the obstacle clearance well of the present invention;

[0038] Figure 6 This is a schematic diagram of the initial support of the present invention;

[0039] Figure 7 This is a schematic diagram of backfilling of the dark excavation section of the present invention;

[0040] Figure 8 This is a flow chart of the dark excavation obstacle removal method of the present invention;

[0041] Fig. 9 It is a schematic diagram of a partial frame structure of the scaffold of the present invention;

[0042] Fig.10 This is a schematic diagram of the hook structure of the present invention;

[0043] Fig.11 This is a schematic diagram of the walkway plate structure of the present invention;

[0044] Fig.12 for Fig.11 Structural cross-section at AA in the middle;

[0045] Fig.13 It is a schematic diagram of the structure of the lower hook of the present invention;

[0046] Fig.14 This is a schematic diagram of the installation block structure of the present invention;

[0047] Fig.15 for Fig.14 Structural cross-section at the middle BB;

[0048] Fig.16 This is a schematic diagram of the structure of the fixing rope of the present invention when in use;

[0049] Fig.17 This is a schematic diagram of the cloth pulling structure of the present invention;

[0050] Fig.18 This is a schematic diagram of the structure of the installation block of the present invention after plugging and hiding;

[0051] Fig.19 This is a schematic diagram of the structure of the slider of the present invention;

[0052] Fig. 20 for Fig.19 Structural cross-section at CC.

[0053] In the figure: 1. frame; 2. dense mesh; 3. walkway board; 4. hook; 5. installation groove; 6. slider; 7. lower hook; 8. installation block; 9. rubber pad; 10. elastic metal plate; 11. limit block; 12. slide groove one; 13. spring; 14. plug block; 15. slide groove two; 16. gear; 17. limit groove; 18. connecting plate; 19. pull cloth; 20. slide groove three; 21. placement groove; 22. rubber cover; 23. push block; 24. fixed plate; 25. movable groove; 26. fixed rope; 27. installation ring; 28. clamping block; 29. ​​magnet one; 30. magnet two; 31. clamping groove; 32. movable block; 33. slide groove four; 34. elastic member. DETAILED DESCRIPTION

[0054] In order to make the purpose and technical solution of the present invention clearly and completely described, and the advantages more clearly understood, the embodiments of the present invention are further described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Example 1: Please refer to Figures 1 to 20 The present invention provides a technical solution: a scaffold for dark excavation and obstacle removal close to the underground continuous wall of an existing station, comprising a frame 1, two walkway boards 3 are installed on the upper part of the frame 1, a dense mesh 2 is arranged on the front side of the frame 1, two installation grooves 5 are arranged on the left and right sides of the walkway board 3, the inner wall of the installation groove 5 is plugged with a mounting block 8, the front and rear sides of the mounting block 8 are both installed with a slider 6, the left and right sides of the mounting blocks 8 are both installed with a hook 4, a movable groove 25 is arranged inside the hook 4, a push block 23 is inserted into the inner wall of the movable groove 25, and a fixed plate is installed on the outer side of the push block 23 24, an insert block 14 is provided on the top of the push block 23, a slide groove 12 is provided on the upper inner side of the mounting block 8, a limit block 11 is installed on the inner wall of the slide groove 12, springs 13 are installed on the adjacent sides of the limit blocks 11 on the left and right sides, a gear 16 is rotatably connected to the inner wall of the mounting block 8, a slide groove 2 15 is provided on the bottom of the mounting block 8, a lower hook 7 is inserted into the inner wall of the slide groove 2 15, rubber pads 9 are installed on the separated sides of the lower hooks 7 on the left and right sides, a limit groove 17 is provided on the adjacent sides of the slide grooves 2 15 on the left and right sides, and a connecting plate 18 is installed on the inner wall of the limit groove 17;

[0056] The adjacent sides of the left and right plug blocks 14 penetrate the hook 4 and are inserted into the inner wall of the mounting block 8. The bottom of the plug block 14 is meshed with the gear 16. The separated sides of the left and right lower hook members 7 are meshed with the gear 16, and the adjacent sides are installed between the connecting plates 18. When the hook 4 is mounted on the surface of the frame 1, the gravity of the walkway plate 3 is used to press downward, driving the push block 23 to push upward, thereby driving the plug block 14 to push the gear 16 to rotate, and then driving the meshed lower hook member 7 to extend downward, while hooking the lower surface of the frame 1, and using the setting of the rubber pad 9, the stability of the installation of the walkway plate 3 is increased, and it is prevented from occurring. The phenomenon of sliding, the fixed plate 24 is slidably connected to the inner wall of the second slide groove 15, and the fixed plate 24 plays a limiting role, thereby preventing the push block 23 from escaping from the movable groove 25, and the bottom of the push block 23 is attached to the surface of the frame 1, and the separated sides of the left and right rubber pads 9 are attached to the surface of the frame 1, so that the rubber pads 9 are used to increase the friction between the hook 4 and the lower hook 7 and the frame 1, thereby improving the anti-slip effect of the walkway plate 3 and improving its installation stability. The slider 6 is inserted into the inner wall of the installation groove 5, and the proximal ends of the left and right springs 13 are installed on the inner wall of the slide groove 12, so that the elastic force of the spring 13 is used to facilitate the reset of the plug block 14.

[0057] When erecting a temporary scaffold, its frame 1 is gradually erected and completed, and the walkway board 3 can be laid at this time. When the walkway board 3 is placed on the surface of the frame 1, the walkway board 3 is pressed downward by its own gravity, driving the pushing block 23 to push upward along the inner wall of the movable groove 25, thereby pushing the insertion block 14 to insert into the inner wall of the mounting block 8, and driving the limit block 11 to squeeze the spring 13, while driving the gear 16 meshing with it to rotate, thereby driving the lower hook 7 to extend downward, and using the connecting plate 18 to slide on the inner wall of the limiting groove 17 to limit the lower hook 7. At this time, the rubber pad 9 will contact the lower surface of the frame 1, thereby utilizing the cooperation between the hook 4 and the lower hook 7 and the rubber pad 9 to increase the stability of the installation between the walkway board 3 and the frame 1, thereby preventing it from sliding.

[0058] Embodiment 2: On the basis of embodiment 1, in order to further improve the installation effect of the walkway plate 3, one of the magnets 29 is installed at the bottom of the lower hook 7, and another magnet 29 is installed on the separated side of the hooks 4 on the left and right sides, and a slide groove 20 is opened inside the hook 4, and an elastic metal plate 10 is inserted into the inner wall of the slide groove 20, and a pull cloth 19 is installed at the bottom of the elastic metal plate 10, and magnets 2 30 are installed on the adjacent sides of the pull cloth 19 on the left and right sides;

[0059] The adjacent sides of the left and right elastic metal plates 10 are both inserted into the bottom of the lower hook 7, the magnet 2 30 is fitted with the middle magnet 1 29, and the elastic metal plate 10 is fitted on the surface of the frame 1, so that the elastic metal plate 10 is used to connect the hook 4 and the lower hook 7 together, further improving the installation effect of the walkway plate 3, and at the same time, the magnetic attraction between the magnet 1 29 and the magnet 2 30 is used to facilitate the resetting of the elastic metal plate 10.

[0060] Pulling the cloth 19 drives the elastic metal plate 10 to extend downward, and at the same time allows the elastic metal plate 10 to slide along the inner wall of the slide groove 3 20, and inserts one side of the elastic metal plate 10 into the inner wall of the lower hook 7. At this time, the magnet 2 30 set on one side of the cloth 19 and the magnet 1 29 at the bottom of the lower hook 7 are magnetically installed to connect the hook 4 and the lower hook 7 together, and cover the frame 1, so as to further improve the stability of the installation of the walkway plate 3.

[0061] Embodiment 3: On the basis of embodiment 2, in order to facilitate folding of the mounting block 8 for storage, and at the same time, without the need for additional ropes to fix the dense mesh 2, and to improve the use effect of the walkway board 3, the left and right hooks 4 are provided with placement grooves 21 on the separated sides, and the left and right placement grooves 21 are hinged with rubber cover plates 22 on the adjacent sides. The bottom wall of the placement groove 21 is provided with a plurality of mounting rings 27, and the outer sides of the plurality of mounting rings 27 are provided with fixing ropes 26;

[0062] The two fixing ropes 26 on the front side are both installed between the dense mesh 2, and the two ends of the fixing rope 26 are respectively installed between the mounting rings 27, so that the dense mesh 2 can be installed and fixed without the aid of additional ropes, thereby improving the practicality of the walkway board 3;

[0063] A plurality of card slots 31 are provided on both sides of the inner wall of the installation slot 5, a slide slot 33 is provided inside the slider 6, a moving block 32 is installed on the inner wall of the slide slot 33, a card block 28 is installed on the separated side of the moving blocks 32 on the front and rear sides, and an elastic member 34 is provided on the inner wall of the slide slot 33;

[0064] The elastic member 34 is arranged on the inner wall of the slide groove 33, and the left and right side blocks 28 both penetrate the slider 6 and are respectively fitted between the two side slots 31. When not in use, the installation block 8 can be inserted into the inner wall of the installation groove 5 by pushing it toward the middle of the walkway plate 3. At the same time, the two blocks 28 are engaged with the two middle slots 31, thereby facilitating the storage of the walkway plate 3.

[0065] When use is finished, the fixing rope 26 is retracted into the two hooks 4 on the front side, and the rubber cover 22 is closed. Then, the magnet 2 30 on one side of the pull cloth 19 is separated from the magnet 1 29 at the bottom of the lower hook 7, and the elastic metal plate 10 is retracted to the inner wall of the hook 4, and the magnetic installation between the magnet 2 30 and the magnet 1 29 on one side of the hook 4 is used to fix the elastic metal plate 10. After completion, the walkway plate 3 is pulled upward. At this time, the elastic force of the spring 13 is used to drive the limit block 11 to move along the inner wall of the slide groove 12, and drive the plug block 14 to follow the movement of the walkway plate 3 and gradually plug into the inner wall of the hook 4. At the same time, the push block 23 is pushed downward. At this time, the lower hook 7 will follow the reset of the plug block 14 and gradually retract to the inner wall of the slide groove 2 15. When the hook 7 is fully retracted to the inner wall of the second slide groove 15, the walkway board 3 can be taken out upward to separate it from the frame 1, and then the mounting block 8 is pushed toward the middle of the walkway board 3, thereby driving the two blocking blocks 28 to be gradually pushed to the inner wall of the mounting groove 5, and at the same time driving the moving block 32 to squeeze the elastic member 34 and compress it. At this time, the blocking block 28 is separated from the blocking grooves 31 on both sides, and continues to push the mounting block 8, allowing the two sliders 6 to be inserted along the inner wall of the mounting groove 5. When the mounting block 8 is fully reset, the elastic force of the elastic member 34 is used to drive the two blocking blocks 28 to be plugged into the inner wall of the middle blocking groove 31, thereby facilitating the retraction of the mounting block 8 to the inner wall of the walkway board 3, so as to facilitate the subsequent storage of the walkway board 3, thereby improving the use effect of the walkway board 3.

[0066] Embodiment 4: Based on Embodiment 3, a construction method for dark excavation and obstacle removal close to the underground continuous wall of an existing station is proposed, including a dark excavation and obstacle removal scaffolding close to the underground continuous wall of an existing station, and the method includes the following steps:

[0067] S1: Carry out MJS horizontal reinforcement under the operating station to reduce the impact of subsequent construction on the operating station;

[0068] S2: Build a scaffold at the bottom of the obstacle clearance well, and fine-tune the height and size of the platform according to the actual situation on site. The scaffold consists of a plurality of frames 1, and two walkway boards 3 are set on the upper part of the frame 1, and a dense mesh 2 is arranged on the front side of the frame 1;

[0069] S3: Horizontal drilling is used to check the reinforcement effect of the soil in front, and grouting reinforcement is carried out if there is water leakage;

[0070] S4: The tunnel door is chiseled out, and the underground continuous wall of the obstacle clearance shaft is broken down layer by layer from top to bottom;

[0071] S5: Following the order of tunnel gate removal, excavate the obstacle clearance well and the sandwich soil between the operating stations in layers and blocks, and carry out initial support;

[0072] S6: Gradually demolish underground continuous walls of operating stations;

[0073] S7: Backfilling of the underground excavation section.

[0074] Ningbo Metro Line 8 Liyuan South Road Station is designed to transfer with the already operational Line 2 Liyuan South Road Station. In order to meet the conditions for the shield section of Line 8 to pass under the Line 2 Liyuan South Road Station, a clearance work pit is set up to secretly excavate and break the ground-connected wall of Line 2 Liyuan South Road Station;

[0075] After comparing the options, it was found that the cost of modifying the shield machine cutterhead was high and the wall grinding would cause irreversible deformation to the operating station structure. Considering the geological characteristics of the soft soil in Ningbo's coastal area, it was confirmed that the dark excavation method would be used for micro-disturbance obstacle removal construction.

[0076] When conducting dark excavation and clearing of obstacles close to the underground continuous wall of the existing station, the water and soil lose support and protection, and the soil inside the tunnel portal is very likely to become unstable and damaged, thus causing a large-scale surface collapse and cracking damage, leading to construction safety accidents and great safety risks. Therefore, before dark excavation, the key points of dark excavation are to strengthen the stratum under the operating station, improve the dark excavation technology and safety measures;

[0077] When the tunnel door is broken and the sandwich soil is excavated, the key points in dark excavation construction are to reduce the exposure time without support, prevent the structure from instability and collapse, and safely and smoothly remove the tunnel door for sandwich soil excavation. In particular, the breaking of underground continuous walls of operating stations is the key point in construction;

[0078] The length of the dark excavation section for obstacle removal is short, but it is close to the operating station, and even the ground connection wall of the operating station needs to be broken;

[0079] It is very easy to cause uneven deformation of the structure and large shear force on the wall. The excavation sequence must be strictly controlled during the dark excavation process, and the unloading must be gradual and timely supported to ensure the stability of the operating station.

[0080] In actual use, when erecting a temporary scaffold, its frame 1 is gradually erected, and the walkway board 3 can be laid at this time. When the walkway board 3 is placed on the surface of the frame 1, the walkway board 3 is pressed downward by its own gravity, driving the pushing block 23 to push upward along the inner wall of the moving groove 25, thereby pushing the insert block 14 to insert into the inner wall of the mounting block 8, and driving the limit block 11 to squeeze the spring 13, while driving the gear 16 meshing with it to rotate, thereby driving the lower hook 7 to extend downward, and using the connecting plate 18 to slide on the inner wall of the limiting groove 17 to limit the lower hook 7. At this time, the rubber pad 9 will contact the lower surface of the frame 1, so as to use the hanging The cooperation between the hook 4 and the lower hook 7 and the rubber pad 9 increases the stability of the installation between the walkway board 3 and the frame 1, thereby preventing the sliding phenomenon. After the installation is completed, the pull cloth 19 is pulled to drive the elastic metal plate 10 to extend downward, and at the same time, the elastic metal plate 10 is allowed to slide along the inner wall of the slide groove 3 20, and one side of the elastic metal plate 10 is plugged into the inner wall of the lower hook 7. At this time, the magnet 2 30 set on one side of the pull cloth 19 is magnetically installed with the magnet 1 29 at the bottom of the lower hook 7, so that the hook 4 and the lower hook 7 are connected together, and the frame 1 is covered, so as to further improve the stability of the installation of the walkway board 3;

[0081] When installing the dense mesh 2, the dense mesh 2 is set on the front side of the frame 1, and the two rubber cover plates 22 on the front side are opened at the same time, and the fixing rope 26 on the inner wall of the placement groove 21 is taken out and wound between the dense mesh 2 and the frame 1, and then wound again between the mounting ring 27 on the inner wall of the placement groove 21 for installation, so that the dense mesh 2 can be installed without the help of additional ropes, thereby improving the practicality and use effect of the walkway board 3;

[0082] When use is finished, the fixing rope 26 is retracted into the two hooks 4 on the front side, and the rubber cover 22 is closed. Then, the magnet 2 30 on one side of the pull cloth 19 is separated from the magnet 1 29 at the bottom of the lower hook 7, and the elastic metal plate 10 is retracted to the inner wall of the hook 4, and the magnetic installation between the magnet 2 30 and the magnet 1 29 on one side of the hook 4 is used to fix the elastic metal plate 10. After completion, the walkway plate 3 is pulled upward. At this time, the elastic force of the spring 13 is used to drive the limit block 11 to move along the inner wall of the slide groove 12, and drive the plug block 14 to follow the movement of the walkway plate 3 and gradually plug into the inner wall of the hook 4. At the same time, the push block 23 is pushed downward. At this time, the lower hook 7 will follow the reset of the plug block 14 and gradually retract to the inner wall of the slide groove 2 15. When the hook 7 is fully retracted to the inner wall of the second slide groove 15, the walkway board 3 can be taken out upward to separate it from the frame 1, and then the mounting block 8 is pushed toward the middle of the walkway board 3, thereby driving the two blocking blocks 28 to be gradually pushed to the inner wall of the mounting groove 5, and at the same time driving the moving block 32 to squeeze the elastic member 34 and compress it. At this time, the blocking block 28 is separated from the blocking grooves 31 on both sides, and continues to push the mounting block 8, allowing the two sliders 6 to be inserted along the inner wall of the mounting groove 5. When the mounting block 8 is fully reset, the elastic force of the elastic member 34 is used to drive the two blocking blocks 28 to be plugged into the inner wall of the middle blocking groove 31, thereby facilitating the retraction of the mounting block 8 to the inner wall of the walkway board 3, so as to facilitate the subsequent storage of the walkway board 3, thereby improving the use effect of the walkway board 3.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A scaffold for clearing obstacles by dark excavation close to the underground continuous wall of an existing station, comprising a frame (1), two walkway plates (3) are installed on the upper part of the frame (1), and a dense mesh (2) is arranged on the front side of the frame (1), characterized in that: The walkway plate (3) is provided with two installation grooves (5) on both the left and right sides, the inner wall of the installation groove (5) is plugged with an installation block (8), the front and rear sides of the installation block (8) are both installed with sliders (6), the left and right sides of the installation blocks (8) are both installed with hooks (4) on the separated sides, the hooks (4) are provided with a movable groove (25) inside, the inner wall of the movable groove (25) is plugged with a push block (23), the outer side of the push block (23) is installed with a fixed plate (24), the top of the push block (23) is provided with an insert block (14), the upper side of the inner side of the installation block (8) is provided with a slide groove (25) (12), a limit block (11) is installed on the inner wall of the slide groove 1 (12), and springs (13) are installed on the adjacent sides of the limit blocks (11) on the left and right sides, the inner wall of the mounting block (8) is rotatably connected with a gear (16), a slide groove 2 (15) is provided at the bottom of the mounting block (8), a lower hook (7) is inserted into the inner wall of the slide groove 2 (15), and rubber pads (9) are installed on the separated sides of the lower hooks (7) on the left and right sides, and a limit groove (17) is provided on the adjacent sides of the slide groove 2 (15) on the left and right sides, and a connecting plate (18) is installed on the inner wall of the limit groove (17); The adjacent sides of the plug blocks (14) on the left and right sides penetrate the hook (4) and are inserted into the inner wall of the mounting block (8); the bottom of the plug block (14) is meshed with the gear (16); the separated sides of the lower hooks (7) on the left and right sides are meshed with the gear (16) and the adjacent sides are installed between the connecting plate (18); the fixed plate (24) is slidably connected to the inner wall of the second slide groove (15); the bottom of the push block (23) is attached to the surface of the frame (1); the separated sides of the rubber pads (9) on the left and right sides are attached to the surface of the frame (1); the slider (6) is inserted into the inner wall of the mounting groove (5); and the adjacent ends of the springs (13) on the left and right sides are installed on the inner wall of the first slide groove (12).

2. The scaffolding for clearing obstacles by digging underground continuous walls close to existing stations according to claim 1 is characterized in that: A magnet (29) is installed at the bottom of the lower hook (7), and another magnet (29) is installed on the separated side of the hooks (4) on the left and right sides. A slide groove (20) is provided inside the hook (4), and an elastic metal plate (10) is inserted into the inner wall of the slide groove (20). A pull cloth (19) is installed at the bottom of the elastic metal plate (10), and magnets (30) are installed on the adjacent sides of the pull cloth (19) on the left and right sides. The adjacent sides of the elastic metal plates (10) on the left and right sides are plugged into the bottom of the lower hook (7), the second magnet (30) is fitted with the middle magnet (29), and the elastic metal plate (10) is fitted on the surface of the frame (1).

3. The scaffolding for clearing obstacles by digging underground continuous walls close to existing stations according to claim 1 is characterized in that: A placement groove (21) is provided on the separated sides of the hooks (4) on the left and right sides, a rubber cover plate (22) is hinged on the adjacent sides of the placement grooves (21) on the left and right sides, a plurality of mounting rings (27) are installed on the bottom wall of the placement grooves (21), and a fixing rope (26) is sleeved on the outer sides of the plurality of mounting rings (27); The two fixing ropes (26) on the front side are both installed between the dense mesh (2), and the two ends of the fixing ropes (26) are respectively installed between the installation rings (27); Two clamping grooves (31) are provided on both sides of the inner wall of the installation groove (5), a sliding groove four (33) is provided inside the sliding block (6), a moving block (32) is installed on the inner wall of the sliding groove four (33), and clamping blocks (28) are installed on the separated sides of the moving block (32) on the front and rear sides, and an elastic member (34) is provided on the inner wall of the sliding groove four (33); The elastic member (34) is fitted with the moving block (32), and the clamping blocks (28) on the left and right sides both penetrate the slider (6) and are respectively fitted between the clamping grooves (31) on the two sides.

4. A construction method for dark excavation and obstacle removal close to an existing underground continuous wall of a station, comprising a dark excavation and obstacle removal scaffold close to an existing underground continuous wall of a station as claimed in any one of claims 1 to 3, characterized in that: The method comprises the following steps: S1: Carry out MJS horizontal reinforcement under the operating station to reduce the impact of subsequent construction on the operating station; S2: erecting a scaffold at the bottom of the obstacle clearance shaft, the scaffold consisting of a plurality of frames (1), with two walkway boards (3) arranged on the upper part of the frames (1), and a dense mesh (2) arranged on the front side of the frames (1); S3: Horizontal drilling is used to check the reinforcement effect of the soil in front, and grouting reinforcement is carried out if there is water leakage; S4: The tunnel door is chiseled out, and the underground continuous wall of the obstacle clearance shaft is broken down layer by layer from top to bottom; S5: Following the order of tunnel gate removal, excavate the obstacle clearance well and the sandwich soil between the operating stations in layers and blocks, and carry out initial support; S6: Gradually demolish underground continuous walls of operating stations; S7: Backfilling of the underground excavation section.

5. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4 is characterized in that: In S1, φ2400mmMJS semicircular horizontal reinforcement is used below the operating station structure floor, with a vertical spacing of 800mm and a horizontal spacing of 1800mm, and the piles are constructed layer by layer from bottom to top and from both sides to the middle.

6. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4 is characterized in that: In S2, the ground-mounted diagonal braces of the scaffold are connected by steel pipes to limit the length-to-curvature ratio or act on the stable structure. A walkway board (3) is laid on each platform, a staircase is set between the upper and lower layers, and a fence about 1.2 meters high is set on the edge, and a dense mesh (2) and a safety warning sign are hung as required; In S2, the angle between the scaffolding support and the ground is not greater than 60°. Considering the limitation of the erection space, the position of the top of the support is changed, and at the same time, the upper, middle and lower positions on both sides are connected to the main reinforcement of the ground-connected wall or the shield steel ring to form a wall connection member, thereby improving the overall stability of the entire frame.

7. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4 is characterized in that: In S3, the exploration holes are distributed at the edge and center of the broken part.

8. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4 is characterized in that: In S4, the tunnel door is manually removed in stages from top to bottom and from both sides to the middle. After the removal is completed, the grid steel frame is installed and concrete is sprayed immediately.

9. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4, characterized in that: In S5, the interlayer soil excavation between the clearance shaft ground wall and the operating station ground wall is 50 cm in scale, and is gradually excavated from top to bottom, from both sides to the middle. After the soil is removed in layers, 4 cm of concrete is sprayed on the upper end of the hole and grid steel bars are installed.

10. The scaffolding and construction method for dark excavation and clearing obstacles close to the underground continuous wall of an existing station according to claim 4, characterized in that: In S6, after the ground wall and sandwich soil of the obstacle clearance work pit are excavated and the initial support is completed, the ground wall of the operating station is demolished; In the above S6, 300mm of the ground wall of the operating station is reserved. A temporary scaffold is first set up to break the front ground wall. After the breaking is completed, the temporary scaffold is removed, and then the remaining 300mm thick ground wall is broken layer by layer from bottom to top. The breaking height is controlled at 1000-1100mm each time. One layer is broken and backfilled. When the backfill strength below meets the conditions of the construction station personnel, the next layer is broken and backfilled. Repeat the operation until the ground wall of the tunnel gate is broken; In S7, the dark excavation section is backfilled with C15 plain concrete to the outer facade of the main inner lining wall of the operating station, and the side tunnel door of the obstacle clearance shaft is backfilled with M5 mortar, and the backfill range is the dark excavation section and the entire foundation pit.

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