Supporting structure and method for underground excavation of electric power tunnel

Abstract

The invention relates to a supporting structure and method for an underground excavation electric power tunnel, and belongs to the field of tunnel engineering.The supporting structure comprises a supporting assembly arranged in the electric power tunnel, a top plate is installed at the top of the supporting assembly, a rotating ring is installed on the top plate, a support is fixedly connected to the supporting assembly, and pushing assemblies are installed on the two sides of the rotating ring; a sliding rod is installed in the support in a sliding mode, a rack is fixedly arranged in the sliding rod, a first motor is fixedly installed on the support, an output shaft of the first motor is connected with a second gear, the second gear and the rack are connected in a meshed mode, and a second motor is installed on the sliding rod. According to the method, the technical means of advance support, refined soil body excavation, high-strength grid erection, high-performance concrete spraying, primary support back grouting and the like are comprehensively applied, and accurate control over surface subsidence and the minimum influence on an existing structure are achieved when the existing building structure is subjected to underneath crossing and overcrossing at the same time.

Description

Technical Field

[0001] The invention relates to a supporting structure and method for a dark-dig power tunnel, belonging to the field of tunnel engineering. Background Art

[0002] With the continuous advancement of urban subway construction, the intersection and parallel construction of new rail lines with existing rail lines are increasing. At the same time, as an important urban infrastructure, power tunnels also need to frequently pass under or over existing building structures. At present, dark tunnel technology has been widely used in such projects, but the existing technology mainly copes with single underpass or overpass situations, and is unable to cope with complex working conditions that require both underpass and overpass.

[0003] For example, the publication number CN116446451A discloses a comprehensive pipe gallery support structure across a power tunnel, which includes retaining piles and concrete slabs. The retaining piles are arranged at intervals on both sides of the power tunnel, and the concrete slabs are erected above the retaining piles, and the ends are connected to the upper ends of the retaining piles on the corresponding sides as a whole. The upper end of the concrete slab is provided with a comprehensive pipe gallery, and the lower end is provided with a waterproof layer. The retaining piles are combined with the concrete slabs to protect the power tunnel structure and improve the structural safety without increasing the load on the top of the power tunnel. The support structure with waterproof function is used to solve the problem that the existing reinforcement of the top soil layer of the power tunnel increases the structural risk, and the reinforcement of the retaining piles will increase the cost.

[0004] Although the above-mentioned support structure can achieve a waterproof function, the existing technology usually adopts a single step of advance support, soil excavation, grid erection, shotcrete, etc. when dealing with dark-digging power tunnels. However, for the complex situation of simultaneously passing under and over existing structures, these methods are not effective in controlling surface subsidence and the impact on existing structures. The existing technology has not been able to effectively solve the problem of not being able to better control surface subsidence and reduce the impact on existing structures when simultaneously passing under and over existing building structures, and cannot ensure construction safety and structural stability. In addition, the existing support structure cannot be moved to the next section in batches for laying bricks on the inner wall of a power tunnel after the bricks are laid, and cannot assist in the laying of bricks on the tunnel wall during the movement of the support structure.

[0005] Therefore, we have made improvements to this and proposed a support structure and method for a dark-digging power tunnel. Summary of the invention

[0006] (I) The technical problem to be solved by the present invention is that the existing technology usually adopts a single step of advance support, soil excavation, grid erection, shotcrete spraying, etc. when dealing with dark-digging power tunnels. However, for the complex situation of simultaneously passing under and over existing structures, these methods are not effective in controlling surface subsidence and the impact on existing structures.

[0007] (II) Technical solution In order to achieve the above-mentioned purpose of the invention, the present invention provides a support structure for a dark-digging power tunnel, including a support assembly arranged in the power tunnel, a top plate is installed on the top of the support assembly, a swivel is installed on the top plate, a bracket is fixedly connected to the support assembly, and push assemblies are installed on both sides of the swivel, a slide bar is slidably installed in the bracket, a rack is fixedly arranged in the slide bar, a first motor is fixedly installed on the bracket, a second gear is connected to the output shaft of the first motor, the second gear and the rack are meshed, a second motor is installed on the slide bar, and the second motor A rotating rod is fixedly connected to the output shaft of , a fixed shaft and a side plate are fixedly connected above the rotating rod, a connecting block is fixedly connected above the fixed shaft, a spring is installed above the connecting block, a connecting frame is connected above the spring, a connecting block is installed above the connecting frame, a driving assembly is installed in the connecting block, a second fixed plate is fixedly connected to the bracket, a folding rod is slidably installed on the second fixed plate, the folding rod and the top plate are fixedly connected, a second groove is opened on the second fixed plate, an advance small guide tube is installed on the top of the power tunnel, and a locking foot anchor pipe and a grouting pipe are installed in the power tunnel.

[0008] Wherein, the support assembly includes a support rod, a roller is installed below the support rod, a first electric push rod is installed inside the support rod, and the first electric push rod is fixedly connected to the top plates on the left and right sides.

[0009] Among them, the top plates are arranged in parallel along a semicircular arc trajectory, the front side of the top plate is set as a stepped structure, installation grooves are opened on both sides of the top plate, docking rods are installed in the installation grooves, a second connecting plate is connected between two adjacent docking rods, and balls are rotatably installed on the docking rods. The top plate forms a first sliding structure with the adjacent top plate through the docking rod and the second connecting plate.

[0010] Among them, the top plate is provided with a first groove, the swivel is installed in the first groove, a gear segment is fixedly connected to the inner wall of the swivel, the gear segment is meshed with a first gear, a third electric push rod is installed at the bottom of the bracket, the third electric push rod is connected to a third motor, the output shaft of the third motor is connected to the first gear, a first connecting plate is fixedly provided on the third motor, a connecting ring is fixedly connected to the first connecting plate, and the connection method between the swivel and the connecting ring is a rotating connection.

[0011] Wherein, the pushing assembly includes a first inner groove opened on both sides of the rotating ring, a second electric push rod is installed in the first inner groove, a push plate is fixedly connected to the second electric push rod, and the length of the push plate is equal to the thickness of the rotating ring.

[0012] Among them, the rotating rod, fixed shaft, side plate and connecting block are a whole, the connecting frame is provided with a sliding groove, the inner wall of the sliding groove and the outer wall of the connecting block are in contact with each other, the side plate and the connecting frame are in contact with each other, and the side plates are symmetrically distributed on both sides of the rotating rod.

[0013] The middle part of the connecting block is a cylindrical structure, and the front and rear sides of the connecting block are both truncated cone structures. The connecting block is suitable for abutting against the inner wall of the second groove when the rotating rod rotates and sliding on the connecting block through the connecting frame.

[0014] Among them, the driving assembly includes a fixed rod fixedly connected to the inside of the connecting block, a fourth motor is fixedly mounted on the fixed rod, a first synchronous wheel is connected to the output shaft of the fourth motor, a synchronous belt is mounted on the outer side of the first synchronous wheel, a second synchronous wheel is mounted above the synchronous belt, and transmission wheels are fixedly arranged on both sides of the second synchronous wheel, the transmission wheel and the connecting block are rotatably connected, the top of the transmission wheel protrudes from the surface of the connecting block, and a second inner groove for placing the synchronous belt is opened in the connecting block.

[0015] The outer peripheral surface of the transmission wheel and the side of the folding rod close to the central axis of the rotating ring are both provided with transverse convex patterns, and the folding rod forms a second sliding structure through the transmission wheel and the second fixed plate.

[0016] A construction method for a supporting structure of a dark-digging power tunnel comprises the following steps: S1: Advance support: To ensure construction safety, advance small pipe reinforcement or deep hole grouting reinforcement is carried out before earth excavation. The small pipe is arranged within the arch range, using Φ32 advance pipe, L=1800@300, elevation angle 15°, longitudinal grid spacing 500mm, deep hole grouting reinforcement range is 500mm inside the primary support and 1500mm outside the primary support, grouting holes are arranged in a circular manner, with an overlap length of 2.0m, grouting wall uses C20 mesh spraying, thickness of 0.3m, HRB400 grade, 22mm diameter anchor rod, length 1.5m, plum blossom arrangement, spacing 0.5×0.5m, single-layer steel mesh Φ6@150×150 is used in the wall, and the overlap length is 150mm; S2: Soil excavation: Excavation is carried out manually. The slag is transported to the shaft slag pit by an electric tricycle transporter, and then lifted to the ground slag bin by a grab bucket. The concealed excavation is carried out by step method. The core soil is reserved for the upper step and the pressure relief groove is reserved for the lower step. The excavation footage of each cycle is controlled at 0.5m, and the distance between the upper and lower steps is 3m~5m. The step excavation is based on the stratum conditions, and the steps are appropriately sloped to ensure the safety of the steps. The excavation should be carried out according to the outer contour line, and the over-excavation is controlled within 5cm, and under-excavation is not allowed; S3: Grid erection: The guide tunnel support adopts grid arch frame and connecting bars, steel mesh and C25 shotcrete support system, with a grid spacing of 500mm. When the grid is erected, the arch crown elevation, centerline deviation, clearance in the tunnel, synchronous mileage and verticality of the arch frame are controlled within the allowable error. The upper step grid arch foot is set with Φ40×2.75, L=2m locking foot anchor pipe. After the grid is erected, Φ22 longitudinal connecting bars are laid on both sides of the grid, with a circumferential spacing of 1000mm, in a plum blossom shape, and reliably welded to the grid arch frame. A single-layer steel mesh is set on the primary support facing the soil side. The steel mesh is made of Φ6.0 wire rod, with a mesh size of 150×150mm for spot welding. The mesh overlap length is 1 grid, and the mesh and the grid are firmly spot welded; S4: Shotcrete: To ensure construction safety, the grid steel arch frame should be sealed with C25 concrete in time after acceptance. The spraying thickness is 250mm. The shotcrete adopts the "tide spraying" process and is sprayed in layers. When the arch shows signs of collapse during excavation, a layer of concrete should be sprayed first, and then the grid frame should be erected. No false spraying or leaking spraying is allowed. The shotcrete should be dense and have a smooth surface. S5: Grouting behind the primary support: After the grid is erected, backfill grouting pipes are buried on the arch and side walls. Grouting uses Φ32, t=2.75mm welded steel pipes. Grouting holes are arranged along the tunnel arch and side walls. The circumferential spacing is 3.0m for the side wall; the longitudinal spacing is 2.0m, and the arch is arranged in a plum blossom shape; the grouting depth is 0.5m behind the primary support, the grouting pipe length is 0.8m, and the grouting slurry uses cement slurry. The grouting pressure behind the primary support is 0.3~0.5MPa, and the final grouting pressure does not exceed 0.5MPa. Backfill grouting is carried out 5m away from the excavation working face; S6: When laying bricks on the tunnel wall, the supporting assembly supports the entire device and changes the initial position of laying, so that the bricks can be placed at the position of the pushing assembly, and the laying position of the tunnel wall bricks can be changed by changing the front and rear positions of the rotating ring, and the laying bricks can be moved along an arc by rotating the rotating ring; S7: After a section of laying is completed, the interior of the power tunnel is supported by a plurality of top plates arranged in parallel, and the top plates at each location are moved one by one. The second gear is driven to rotate by the first motor, driving the rack to slide, and then the slide bar is slid back and forth inside the bracket, thereby changing the initial position of the second motor and the rotating rod. The spring makes the top of the connecting block contact with the folding rod at the corresponding position, and the folding rod drives the top plate at the corresponding position to slide between two adjacent second fixed plates through the driving assembly; S8: When it is necessary to drive the top plates at other positions to move, the second motor drives the rotating rod to rotate, so that the connecting block rotates to the bottom of the top plates at other positions. After the connecting block and the top plate are in frictional contact, the driving assembly drives the top plate to slide between two adjacent second fixed plates again, so that the top plates at each position gradually reduce their supporting force on the inner wall of the previous tunnel.

[0017] (III) Beneficial effects The supporting structure and method of a dark-digging power tunnel provided by the present invention have the following beneficial effects: 1. Through the comprehensive use of advanced support, refined soil excavation, high-strength grid erection, high-performance concrete spraying and grouting behind the primary support and other technical means, precise control of surface subsidence and minimized impact on existing structures are achieved when simultaneously passing under and over existing building structures. This not only improves construction efficiency and safety, but also significantly reduces interference and damage to the surrounding environment, and has important practical application value.

[0018] 2. By setting up the third motor, the first gear and the gear segment, the device can support the swivel through the first connecting plate and the connecting ring when in use, so that the swivel can rotate within a certain angle range, and then the bricks to be laid can be pushed in a clockwise or counterclockwise direction through the pushing assembly. The device can also adjust the position of the swivel and the pushing assemblies on both sides of the swivel in the first groove by extending or shortening the third electric push rod, so that the bricks can be pushed forward or backward by the pushing assemblies later, thereby enhancing the functionality of the support structure. The device can utilize the rollers on the support assembly, and the support structure can assist in the laying of bricks during the movement, thereby solving the problem of assisting in the laying of tunnel wall bricks during the process in which the existing support structure cannot move.

[0019] 3. The device is provided with a support assembly, which can support the top plates on the far left and the far right. The top plates can be docked through the mounting grooves and the docking rods, so that the device can synchronously move the top plates at multiple positions to adjust the initial position of the support structure. When the device is working, the second motor can drive the rotating rod to rotate, and the connecting block above the rotating rod can move from one of the second grooves to the next second groove, thereby driving the top plates at different positions to move forward one by one. The multiple top plates installed in parallel can ensure the support effect of the front and rear sections of the tunnel construction area by driving them one by one, thereby continuously providing a stable support effect. Compared with the overall movement, the support structure is safer when moving, which solves the problem that the existing support structure cannot move the top support to the next section for laying in batches after the bricks of the inner wall of a section of the power tunnel are laid.

[0020] 4. Through the set driving assembly, the fourth motor on the driving assembly is used to drive the first synchronous wheel to rotate, thereby driving the second synchronous wheel and the transmission wheel to rotate through the synchronous belt, so that after the transmission wheel abuts against the folding rod, it drives the folding rod to slide between two adjacent second fixed plates. During the sliding process, the folding rod can gradually transfer the entire device to the next tunnel area that needs support, thereby enhancing the stability of the device during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 A magnified schematic diagram of the structure at center A; Figure 3 for Figure 1 A magnified schematic diagram of the structure at B in the middle; Figure 4 This is a schematic diagram of the internal structure of the connection block of the present invention; Figure 5 This is a schematic diagram of the connection structure between the swivel and the gear segment of the present invention; Figure 6 for Figure 5 A magnified schematic diagram of the structure at C in the middle; Figure 7 for Figure 5 A magnified schematic diagram of the structure at D in the middle; Figure 8 This is a schematic diagram of the connection structure between the bracket and the second fixing plate of the present invention; Fig. 9 for Figure 8 A magnified schematic diagram of the structure at E in the middle; Fig.10 It is a schematic diagram of the connection structure of the swivel and the push assembly of the present invention; Fig.11 for Fig.10 A magnified schematic diagram of the structure at F in the middle; Fig.12 It is a schematic diagram of the overall structure of the top plate of the present invention; Fig.13 for Fig.12 A magnified schematic diagram of the structure at G in the middle; Fig.14 This is a flow chart of the power tunnel construction of the present invention; Fig.15 This is a schematic diagram of the step method excavation construction of the present invention; Fig.16 This is a schematic diagram of the locking foot anchor pipe structure of the present invention; Fig.17 This is a process flow chart of the sprayed concrete construction process of the present invention; Fig.18 This is a schematic diagram of the front view structure of the grouting pipe of the present invention; Fig.19It is a schematic diagram of the side structure of the grouting pipe of the present invention.

[0023] 1. Support assembly; 101. Support rod; 102. Roller; 103. First electric push rod; 2. Top plate; 3. First groove; 4. Rotating ring; 5. Gear section; 6. First gear; 7. Connecting ring; 8. First connecting plate; 9. Push assembly; 901. First inner groove; 902. Second electric push rod; 903. Push plate; 10. Third electric push rod; 11. Bracket; 12. Sliding rod; 13. Rack; 14. First motor; 15. Second gear; 16. Second motor; 17. Rotating rod; 18. Fixed shaft; 19. Side plate; 20. Connecting frame ; 21. Connecting block; 22. Spring; 23. Connecting block; 24. Second fixed plate; 25. Folding rod; 26. Third motor; 27. Second groove; 28. Slide groove; 29. ​​Driving assembly; 2901. Fixed rod; 2902. Fourth motor; 2903. First synchronous wheel; 2904. Synchronous belt; 2905. Second synchronous wheel; 2906. Transmission wheel; 2907. Second inner groove; 30. Mounting groove; 31. Docking rod; 32. Second connecting plate; 33. Ball; 34. Advance small guide tube; 35. Lock foot anchor pipe; 36. Grouting pipe. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples of the specification. The following examples are only used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0025] Embodiment 1: like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 and Fig.19 As shown, this embodiment proposes a support structure for a dark-digging power tunnel, including a support assembly 1 arranged in the power tunnel, a top plate 2 is installed on the top of the support assembly 1, a swivel 4 is installed on the top plate 2, a bracket 11 is fixedly connected to the support assembly 1, and the bracket 11 can cooperate with the support assembly 1 to adjust the support height and support position of the support structure, and push assemblies 9 are installed on both sides of the swivel 4, as shown in FIG. Fig.10As shown, the pushing assembly 9 can adjust the position of the brick body of the inner wall of the tunnel during the rotation of the rotating ring 4, so as to realize the auxiliary construction function. A sliding rod 12 is slidably installed in the bracket 11, and a rack 13 is fixedly arranged in the sliding rod 12. A first motor 14 is fixedly installed on the bracket 11, and a second gear 15 is connected to the output shaft of the first motor 14. The second gear 15 and the rack 13 are meshingly connected. A second motor 16 is installed on the sliding rod 12, and a rotating rod 17 is fixedly connected to the output shaft of the second motor 16. The first motor 14 is used to drive the second gear 15 to rotate, thereby driving the rack 13 and the sliding rod 12 to slide on the bracket 11, so as to subsequently adjust the initial position of the rotating rod 17. A fixed shaft 18 and a side plate 19 are fixedly connected above the rotating rod 17, and a connecting block 21 is fixedly connected above the fixed shaft 18. A spring 22 is installed above the connecting block 21, and a connecting frame 20 is connected above the spring 22. A connecting block 23 is installed above the connecting frame 20, and a driving assembly 29 is installed in the connecting block 23. A second fixed plate 24 is fixedly connected to the bracket 11, and a folding rod 25 is slidably installed on the second fixed plate 24. The folding rod 25 and the top plate 2 are fixedly connected. A second groove 27 is opened on the second fixed plate 24. An advance small guide tube 34 is installed on the top of the power tunnel, and a locking foot anchor pipe 35 and a grouting pipe 36 are installed in the power tunnel. The second motor 16 is used to drive the rotating rod 17 to rotate, so that the connecting block 23 moves from the folding rod 25 between two adjacent second fixed plates 24 to the next folding rod 25, so that the device can realize a step-by-step transfer function during the support and transfer process, thereby enhancing the safety of the device when in use.

[0026] Embodiment 2: The solution in Example 1 is further introduced below in combination with a specific working method, as described below: like Figure 1 As shown, as a preferred embodiment, on the basis of the above method, further, the support assembly 1 includes a support rod 101, a roller 102 is installed under the support rod 101, the roller 102 is used to change the initial position of the entire device, and a first electric push rod 103 is installed in the support rod 101. The first electric push rod 103 is fixedly connected to the top plates 2 on the left and right sides. The first electric push rod 103 can change the support height of the device to adapt to the use of power tunnels of different heights.

[0027] like Figure 1 , Fig.12 and Fig.13As shown, as a preferred embodiment, on the basis of the above method, further, the top plates 2 are arranged in parallel along a semicircular arc trajectory, the front side of the top plates 2 is set as a stepped structure, and installation grooves 30 are opened on both sides of the top plates 2, and docking rods 31 are installed in the installation grooves 30, and a second connecting plate 32 is connected between the two adjacent docking rods 31. Balls 33 are rotatably installed on the docking rods 31. The top plates 2 form a first sliding structure with the adjacent top plates 2 through the docking rods 31 and the second connecting plates 32. The docking rods 31 and the second connecting plates 32 can be installed inside the two adjacent top plates 2, so that the two adjacent top plates 2 can slide back and forth, and the balls 33 can reduce the sliding resistance of the top plates 2 without affecting the supporting effect of the top plates 2.

[0028] like Figure 1 , Figure 5 and Figure 6 As shown, as a preferred embodiment, on the basis of the above method, further, a first groove 3 is opened on the top plate 2, the swivel 4 is installed in the first groove 3, a gear segment 5 is fixedly connected to the inner wall of the swivel 4, and a first gear 6 is meshedly connected to the gear segment 5, a third electric push rod 10 is installed at the bottom of the bracket 11, and a third motor 26 is connected to the third electric push rod 10, and the output shaft of the third motor 26 is connected to the first gear 6, a first connecting plate 8 is fixedly provided on the third motor 26, and a connecting ring 7 is fixedly connected to the first connecting plate 8, and the connection method between the swivel 4 and the connecting ring 7 is a rotating connection.

[0029] like Figure 7 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the push assembly 9 includes a first inner groove 901 opened on both sides of the rotating ring 4, a second electric push rod 902 is installed in the first inner groove 901, and a push plate 903 is fixedly connected to the second electric push rod 902. The length of the push plate 903 is equal to the thickness of the rotating ring 4. By extending the second electric push rod 902, the push plate 903 lifts the inner wall brick body of the power tunnel ( Fig.10 As can be seen from the dotted line in the middle), by rotating or moving the swivel 4 forwards and backwards, the device can change the support position while assisting in laying the bricks.

[0030] like Figure 8 and Fig. 9 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the rotating rod 17, the fixed shaft 18, the side plate 19 and the connecting block 21 are a whole, and a slide groove 28 is opened on the connecting frame 20. The inner wall of the slide groove 28 and the outer wall of the connecting block 21 fit together, and the side plates 19 and the connecting frame 20 fit together. The side plates 19 are symmetrically distributed on both sides of the rotating rod 17. The connecting frame 20 can slide up and down between the two side plates 19 through the slide groove 28 and the connecting block 21, so as to gradually transfer the support structure later.

[0031] like Figure 3 , Fig. 9 , Fig.10 and Fig.11 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the middle part of the connecting block 23 is a cylindrical structure, and the front and rear sides of the connecting block 23 are both truncated cone structures. The connecting block 23 is suitable for abutting against the inner wall of the second groove 27 and sliding on the connecting block 21 through the connecting frame 20 when the rotating rod 17 rotates. By utilizing the arc surface structure of the connecting block 23 and the inner wall of the second groove 27, the connecting block 23 can shrink and move from one of the second grooves 27 to the next second groove 27 during the circular motion of the connecting block 23, so as to gradually transfer the support structure while ensuring the supporting effect.

[0032] like Figure 4 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the driving assembly 29 includes a fixed rod 2901 fixedly connected to the inside of the connecting block 23, a fourth motor 2902 is fixedly installed on the fixed rod 2901, a first synchronous wheel 2903 is connected to the output shaft of the fourth motor 2902, a synchronous belt 2904 is installed on the outer side of the first synchronous wheel 2903, a second synchronous wheel 2905 is installed above the synchronous belt 2904, and transmission wheels 2906 are fixedly arranged on both sides of the second synchronous wheel 2905, and the transmission wheel 2906 is fixedly arranged on the outer side of the first synchronous wheel 2903. There is a rotational connection between 906 and the connecting block 23. The top of the transmission wheel 2906 protrudes from the surface of the connecting block 23. A second inner groove 2907 for placing the synchronous belt 2904 is opened in the connecting block 23. The first synchronous wheel 2903 is driven to rotate by the fourth motor 2902 on the fixed rod 2901, so that the synchronous belt 2904 drives the second synchronous wheel 2905 and the transmission wheel 2906 to rotate. When the transmission wheel 2906 rotates, it can move the top part of the device forward in batches, so that the device can play a pre-support function during transfer.

[0033] like Figure 4 and Fig.11 As shown, as a preferred embodiment, on the basis of the above-mentioned method, further, the outer peripheral surface of the transmission wheel 2906 and the side of the folding rod 25 close to the central axis of the rotating ring 4 are provided with transverse convex grooves, and the folding rod 25 forms a second sliding structure between the transmission wheel 2906 and the second fixed plate 24. The convex grooves on the transmission wheel 2906 and the folding rod 25 make the two contact with each other by friction. The transmission wheel 2906 drives the folding rod 25 to move during the rotation process, thereby driving the folding rod 25 at each position to slide on the second fixed plate 24 one by one.

[0034] Embodiment 3: The schemes in Example 1 and Example 2 are further introduced below in combination with specific working methods, as described below for details: Specifically, when the supporting structure of the dark-excavated power tunnel is used: Figure 1 , Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 and Fig.19 As shown, in order to ensure construction safety, advance small pipe 34 reinforcement or deep hole grouting reinforcement is carried out before earth excavation. The small pipe is arranged within the arch range, and a Φ32 advance pipe is used, L=1800@300, an elevation angle of 15°, and a longitudinal grid spacing of 500mm. The deep hole grouting reinforcement range is 500mm inside the primary support and 1500mm outside the primary support. The grouting holes are arranged in a ring shape with an overlap length (reserved grouting wall) of 2.0m. The grouting wall adopts C20 mesh spraying with a thickness of 0.3m, and adopts HRB400 grade, 22mm diameter anchor rods with a length of 1.5m, a plum blossom shape arrangement, and a spacing of 0.5×0.5m. The wall is equipped with a single-layer steel mesh Φ6@150×150 with an overlap length of 150mm. Excavation is done manually. The slag is transported to the shaft slag pit by an electric tricycle transporter, and then lifted to the ground slag bin by a grab bucket. The concealed excavation is done by step method. The core soil is reserved for the upper step and the pressure relief groove is reserved for the lower step. The excavation advance per cycle is controlled at 0.5m, and the distance between the upper and lower steps is 3m~5m. The step excavation is based on the stratum conditions, and the steps are appropriately sloped to ensure the safety of the steps. The excavation should be carried out according to the outer contour line, and the over-excavation is controlled within 5cm, and under-excavation is not allowed. The guide tunnel support adopts grid arch frame and connecting reinforcement, steel mesh and C25 shotcrete support system, with a grid spacing of 500mm. When the grid frame is erected, the arch crown elevation, centerline deviation, clearance in the tunnel, synchronous mileage and verticality of the arch frame are controlled within the allowable error. The upper step grid arch foot is set with Φ40×2.75, L=2m locking foot anchor pipe 35. After the grid is erected, Φ22 longitudinal connecting reinforcement is arranged on both sides of the grid inside and outside, with a circumferential spacing of 1000mm, and a plum blossom shape. It is reliably welded to the grid arch frame. A single-layer steel mesh is set on the soil side of the initial support. The steel mesh is made of Φ6.0 wire rod, with a mesh size of 150×150mm for spot welding. The mesh lap length is 1 grid, and the mesh and the grid are firmly spot welded. In order to ensure construction safety, the grid steel arch frame should be sprayed with C25 concrete in time after acceptance, with a spraying thickness of 250mm. The sprayed concrete adopts the "tide spraying" process and is sprayed in layers. When there are signs of collapse of the arch during excavation, a layer of concrete should be sprayed first, and then the grid should be erected. No false spraying or leaking spraying is allowed. The sprayed concrete should be dense and have a smooth surface. After the grid is erected, a backfill grouting pipe 36 is buried on the arch and side wall. Grouting adopts Φ32, t=2.75mm welded steel pipe. The grouting holes are arranged along the tunnel arch and side wall. The circumferential spacing is: 3.0m for the side wall; the longitudinal spacing is 2.0m, and the arch is arranged in plum blossom shape; the grouting depth is 0.5m behind the primary support, the length of the grouting pipe 36 is 0.8m, and the grouting slurry adopts cement slurry. The grouting pressure behind the primary support is 0.3~0.5MPa, and the final grouting pressure does not exceed 0.5MPa. The backfill grouting is carried out 5m away from the excavation working face; like Figure 1 As shown, when laying the bricks of the tunnel wall, the whole device is supported by the support rod 101 on the support assembly 1, the roller 102 is used to change the initial position of the device, and the first electric push rod 103 can adjust the height of the top plate 2 at each location so that the device can adapt to the support work of power tunnels of different heights. The bricks can be placed at the position of the top push assembly 9, as shown in FIG. Fig.10 As shown, by extending or shortening the third electric push rod 10 on the bracket 11, the front and rear positions of the swivel 4 are changed, thereby changing the position of the tunnel wall brick body during auxiliary laying. Figure 1 , Figure 5 , Figure 6 and Figure 8 As shown, the connecting ring 7 and the first connecting plate 8 enable the swivel 4 to be stably connected to the third motor 26. The third motor 26 drives the first gear 6 to rotate, driving the swivel 4 and the gear segment 5 to rotate. By rotating the swivel 4, the laid bricks move along an arc, so that the device can change the position of the bricks to be laid as needed, thereby realizing the function of auxiliary laying during the support process.

[0035] like Figure 1 , Figure 2 , Figure 3, Figure 4 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 and Fig.13 As shown, the docking rod 31 and the second connecting plate 32 are installed into the installation groove 30 in the two adjacent top plates 2, so that the top plates 2 at each location are connected to each other and can slide back and forth between the two adjacent top plates 2. The ball 33 can reduce the resistance of the top plates 2 when sliding. The interior of the power tunnel is supported by multiple top plates 2 arranged in parallel. When it is necessary to pre-support the upper step part of the tunnel after excavation, the top plates 2 at each location are moved one by one, and the second gear 15 is driven to rotate by the first motor 14, driving the rack 13 to slide, and then the slide bar 12 slides back and forth inside the bracket 11, thereby changing the initial position of the second motor 16 and the rotating rod 17, and the spring 22 makes the top of the connecting block 23 abut against the folding rod 25 at the corresponding position. As shown Figure 4 and Fig.11 As shown, the first synchronous wheel 2903 is driven to rotate by the fourth motor 2902 on the fixed rod 2901, so that the synchronous belt 2904 drives the second synchronous wheel 2905 and the transmission wheel 2906 to rotate. When the transmission wheel 2906 rotates, the folding rods 25 of the device can be transferred one by one, so that the device can play a pre-support function during the transfer. After the laying of the bricks of the inner wall of a section of the power tunnel is completed, the folding rods 25 are gradually moved to the next section for laying. The driving component 29 enables the folding rods 25 to drive the top plate 2 at the corresponding position to slide between the two adjacent second fixed plates 24. When it is necessary to drive the top plate 2 at other positions to move, the second motor 16 is used to drive the rotating rod 17 to rotate, and the arc surface of the connecting block 23 and the arc surface structure of the inner wall of the second groove 27 are used to enable the connecting block 23 to contract and compress the spring 22 when performing circular motion, and then rotate to the bottom of the top plate 2 at other positions. After the connecting block 23 is in frictional contact with the top plate 2, the driving assembly 29 is used again to drive the top plate 2 to slide between the two adjacent second fixed plates 24 according to the same steps as above, so that the top plate 2 at each position gradually reduces the supporting force on the inner wall of the previous tunnel section to enhance the supporting effect of the device.

[0036] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be included in the scope of the claims of the present invention.

Claims

1. A support structure for a dark-dug power tunnel, comprising a support assembly (1) arranged in the power tunnel, characterized in that: A top plate (2) is installed on the top of the support assembly (1), a rotating ring (4) is installed on the top plate (2), a bracket (11) is fixedly connected to the support assembly (1), and push assemblies (9) are installed on both sides of the rotating ring (4), a slide bar (12) is slidably installed in the bracket (11), a rack (13) is fixedly arranged in the slide bar (12), a first motor (14) is fixedly installed on the bracket (11), a second gear (15) is connected to the output shaft of the first motor (14), and the second gear (15) and the rack (13) are meshingly connected, a second motor (16) is installed on the slide bar (12), a rotating rod (17) is fixedly connected to the output shaft of the second motor (16), and a fixed gear (13) is fixedly connected above the rotating rod (17). A shaft (18) and a side plate (19); a connecting block (21) is fixedly connected above the fixed shaft (18); a spring (22) is installed above the connecting block (21); a connecting frame (20) is connected above the spring (22); a connecting block (23) is installed above the connecting frame (20); a driving assembly (29) is installed in the connecting block (23); a second fixing plate (24) is fixedly connected to the bracket (11); a folding rod (25) is slidably installed on the second fixing plate (24); the folding rod (25) and the top plate (2) are fixedly connected; a second groove (27) is provided on the second fixing plate (24); an advance small guide tube (34) is installed on the top of the power tunnel; and a locking foot anchor pipe (35) and a grouting pipe (36) are installed in the power tunnel.

2. A supporting structure for a dark-excavated power tunnel according to claim 1, characterized in that: The support assembly (1) comprises a support rod (101), a roller (102) is installed below the support rod (101), a first electric push rod (103) is installed inside the support rod (101), and the first electric push rod (103) is fixedly connected to the top plates (2) on the left and right sides.

3. A supporting structure for a dark-excavated power tunnel according to claim 2, characterized in that: The top plates (2) are arranged in parallel along a semicircular arc track, the front side of the top plates (2) is arranged as a stepped structure, both sides of the top plates (2) are provided with mounting grooves (30), docking rods (31) are installed in the mounting grooves (30), a second connecting plate (32) is connected between two adjacent docking rods (31), a ball bearing (33) is rotatably installed on the docking rods (31), and the top plates (2) form a first sliding structure with adjacent top plates (2) via the docking rods (31) and the second connecting plate (32).

4. A supporting structure for a dark-excavated power tunnel according to claim 3, characterized in that: The top plate (2) is provided with a first groove (3), the rotating ring (4) is installed in the first groove (3), a gear segment (5) is fixedly connected to the inner wall of the rotating ring (4), a first gear (6) is meshedly connected to the gear segment (5), a third electric push rod (10) is installed at the bottom of the bracket (11), a third motor (26) is connected to the third electric push rod (10), an output shaft of the third motor (26) is connected to the first gear (6), a first connecting plate (8) is fixedly provided on the third motor (26), a connecting ring (7) is fixedly connected to the first connecting plate (8), and the connection between the rotating ring (4) and the connecting ring (7) is a rotational connection.

5. A supporting structure for a dark-excavated power tunnel according to claim 4, characterized in that: The push assembly (9) comprises a first inner groove (901) opened on both sides of the rotating ring (4), a second electric push rod (902) is installed in the first inner groove (901), a push plate (903) is fixedly connected to the second electric push rod (902), and the length of the push plate (903) is equal to the thickness of the rotating ring (4).

6. The supporting structure of a dark-excavated power tunnel according to claim 1, characterized in that: The rotating rod (17), the fixed shaft (18), the side plate (19) and the connecting block (21) are integrated into a whole. The connecting frame (20) is provided with a slide groove (28). The inner wall of the slide groove (28) and the outer wall of the connecting block (21) are in contact with each other. The side plate (19) and the connecting frame (20) are in contact with each other. The side plates (19) are symmetrically distributed on both sides of the rotating rod (17).

7. The supporting structure of a dark-excavated power tunnel according to claim 1, characterized in that: The middle portion of the connecting block (23) is a cylindrical structure, and the front and rear sides of the connecting block (23) are both truncated cone structures. The connecting block (23) is suitable for abutting against the inner wall of the second groove (27) and sliding on the connecting block (21) through the connecting frame (20) when the rotating rod (17) rotates.

8. The supporting structure of a dark-excavated power tunnel according to claim 1, characterized in that: The driving assembly (29) comprises a fixing rod (2901) fixedly connected to the inside of the connecting block (23); a fourth motor (2902) is fixedly mounted on the fixing rod (2901); a first synchronous wheel (2903) is connected to the output shaft of the fourth motor (2902); a synchronous belt (2904) is mounted on the outer side of the first synchronous wheel (2903); a second synchronous wheel (2905) is mounted above the synchronous belt (2904); transmission wheels (2906) are fixedly mounted on both sides of the second synchronous wheel (2905); the transmission wheel (2906) and the connecting block (23) are rotatably connected; the top of the transmission wheel (2906) protrudes from the surface of the connecting block (23); and a second inner groove (2907) for accommodating the synchronous belt (2904) is provided in the connecting block (23).

9. A supporting structure for a dark-excavated power tunnel according to claim 8, characterized in that: The outer peripheral surface of the transmission wheel (2906) and the side of the folding rod (25) close to the central axis of the rotating ring (4) are both provided with transverse convex patterns, and the folding rod (25) forms a second sliding structure between the transmission wheel (2906) and the second fixed plate (24).

10. A construction method for a support structure of a dark-digging electric power tunnel, using the support structure of a dark-digging electric power tunnel according to claim 1, characterized in that: The steps include: S1: Advance support: To ensure construction safety, advance small pipe (34) reinforcement or deep hole grouting reinforcement is carried out before excavation. The small pipe is arranged within the arch. A Φ32 advance pipe is used, L=1800@300, elevation angle 15°, longitudinal grid spacing 500mm, deep hole grouting reinforcement range is 500mm inside the primary support and 1500mm outside the primary support. The grouting holes are arranged in a circular manner with an overlap length of 2.0m. The stop wall is made of C20 mesh sprayed concrete with a thickness of 0.3m. HRB400 grade, 22mm diameter anchor rods are used, 1.5m long, arranged in plum blossom shape, with a spacing of 0.5×0.5m. A single-layer steel mesh Φ6@150×150 is provided inside the wall with an overlap length of 150mm. S2: Soil excavation: Excavation is carried out manually. The slag is transported to the shaft slag pit by an electric tricycle transporter, and then lifted to the ground slag bin by a grab bucket. The concealed excavation is carried out by step method. The core soil is reserved for the upper step and the pressure relief groove is reserved for the lower step. The excavation footage of each cycle is controlled at 0.5m, and the distance between the upper and lower steps is 3m~5m. The step excavation is based on the stratum conditions, and the steps are appropriately sloped to ensure the safety of the steps. The excavation should be carried out according to the outer contour line, and the over-excavation is controlled within 5cm, and under-excavation is not allowed; S3: Grid erection: The guide tunnel support adopts grid arch frame and connecting bars, steel mesh and C25 shotcrete support system, with a grid spacing of 500mm. When the grid is erected, the arch crown elevation, centerline deviation, clearance in the tunnel, synchronous mileage and verticality of the arch frame are controlled within the allowable error. The upper step grid arch foot is set with Φ40×2.75, L=2m locking foot anchor pipe. After the grid is erected, Φ22 longitudinal connecting bars are laid on both sides of the grid, with a circumferential spacing of 1000mm, in a plum blossom shape, and reliably welded to the grid arch frame. A single-layer steel mesh is set on the primary support facing the soil side. The steel mesh is made of Φ6.0 wire rod, with a mesh size of 150×150mm for spot welding. The mesh overlap length is 1 grid, and the mesh and the grid are firmly spot welded; S4: Shotcrete: To ensure construction safety, the grid steel arch frame should be sealed with C25 concrete in time after acceptance. The thickness of the shotcrete is 250mm. The shotcrete adopts the "tide shotcrete" process and is shotcreted in layers. When the arch shows signs of collapse during excavation, a layer of concrete should be shot first, and then the grid frame should be erected. No false shotcrete or missed shotcrete is allowed. The shotcrete should be dense and have a smooth surface. S5: Grouting behind the primary support: After the grid is erected, a backfill grouting pipe (36) is buried on the arch and side wall. Grouting uses a Φ32, t=2.75mm welded steel pipe. Grouting holes are arranged along the tunnel arch and side wall. The circumferential spacing is 3.0m for the side wall; the longitudinal spacing is 2.0m, and the arch is arranged in a plum blossom shape. The grouting depth is 0.5m behind the primary support. The length of the grouting pipe (36) is 0.8m. The grouting slurry uses cement slurry. The grouting pressure behind the primary support is 0.3~0.5MPa. The final grouting pressure does not exceed 0.5MPa. The backfill grouting is carried out 5m away from the excavation working face. S6: When laying bricks on the tunnel wall, the supporting assembly (1) supports the entire device and changes the initial laying position, so that the bricks can be placed at the position of the pushing assembly (9). By changing the front and rear positions of the rotating ring (4), the laying position of the bricks on the tunnel wall is changed. By rotating the rotating ring (4), the laid bricks are moved along an arc. S7: After a section of laying is completed, the interior of the power tunnel is supported by a plurality of top plates (2) arranged in parallel, and the top plates (2) at each location are moved one by one. The second gear (15) is driven to rotate by the first motor (14), driving the rack (13) to slide, thereby causing the slide bar (12) to slide back and forth inside the bracket (11), thereby changing the initial positions of the second motor (16) and the rotating rod (17). The spring (22) causes the top of the connecting block (23) to abut against the folding rod (25) at the corresponding position, and the folding rod (25) drives the top plate (2) at the corresponding position to slide between two adjacent second fixed plates (24) through the driving assembly (29); S8: When it is necessary to drive the top plates (2) at other positions to move, the second motor (16) is used to drive the rotating rod (17) to rotate, so that the connecting block (23) rotates to the bottom of the top plates (2) at other positions. After the connecting block (23) and the top plates (2) are in frictional contact, the driving assembly (29) is used again to drive the top plates (2) to slide between two adjacent second fixed plates (24), so that the top plates (2) at each position gradually reduce the supporting force on the inner wall of the previous tunnel.

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