A device for grouting and reinforcing a collapse tunnel

Abstract

The application discloses a kind of stacked tunnel grouting reinforcement devices, including existing tunnel and new tunnel, excavation area is respectively arranged in the both sides of existing tunnel, reinforcement wall is arranged in the inner wall of excavation area, borehole is drilled from reinforcement wall to new tunnel, and reinforcement tube is inserted, cavity is arranged in the inner wall of reinforcement tube, grout hole is uniformly arranged on the outer wall of reinforcement tube, the position corresponding to the lower end of reinforcement tube of new tunnel is paved with special pipe piece, the recess of special pipe piece is arranged, the through hole of recess bottom is opened, the support groove is formed after the annular support of a plurality of special pipe pieces, and support ring is arranged in support groove;The side of support ring close to reinforcement tube is provided with connecting piece, and reinforcement tube is inserted into pull anchor rod from top to bottom after special pipe piece is paved, the lower end of pull anchor rod is connected with connecting piece, and the bottom of the side of support ring away from reinforcement tube is provided with pad assembly.The application uses the mode of pulling up and pushing down, avoids the position defects of vertical area between existing tunnel and new tunnel and local soft soil area that cannot be vertically reinforced by existing tunnel above.

Description

Technical Field

[0001] This invention relates to the field of grouting reinforcement technology for stacked tunnels, and more particularly to a grouting reinforcement device for stacked tunnels. Background Technology

[0002] In tunnel engineering, the initial support of tunnels typically employs a "reinforced ring" structure. This involves driving anchor bolts circumferentially along the inner wall of the tunnel after excavation, forming a ring-shaped support system. The anchor bolts are perpendicular to the rock surface, reinforcing the surrounding rock to form a load-bearing ring. When in operation, the anchor bolts bear axial tensile force, pulling the surrounding rock pressure towards the center of the reinforced ring. The stress characteristic of this ring-shaped support structure is that the anchor bolts collectively pull the surrounding rock towards the center of the reinforced ring, causing the surrounding rock to form an integral load-bearing arch to resist the ground pressure around the tunnel.

[0003] However, the existing ring support structure has significant limitations when facing specific intersecting tunnel conditions. When a new tunnel passes vertically beneath an existing operating tunnel, the presence of existing facilities such as track bed and rails in the operating tunnel above makes it impossible to directly install tie rods for reinforcement between the two tunnels. Even more problematic is the presence of soft soil areas between the two tunnels. Soft soil strata have poor self-stability and are difficult to deform, meaning that the load from the operating tunnel above and the disturbances caused by the construction of the new tunnel below can be transmitted through the soft soil area, affecting the structural safety of both tunnels.

[0004] The existing ring support structure sets all anchors radially towards the tunnel center, with the force direction all pulling towards the center of the reinforcement ring. Although this force distribution mode can form a load-bearing ring around the tunnel itself, it cannot provide effective directional support for the soft soil area between two tunnels. That is, it cannot direct the support force towards the soft soil area to resist the transmission of the load from above through the soft soil area and the ground disturbance caused by the excavation of the tunnel below. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a grouting reinforcement device for stacked tunnels, thereby solving the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A grouting reinforcement device for a stacked tunnel includes an existing tunnel and a newly excavated tunnel. Excavation zones are set on both sides of the existing tunnel. A reinforcement wall is set on the inner wall of the excavation zone. A hole is drilled into the newly excavated tunnel from the reinforcement wall and a reinforcement pipe is inserted. A cavity is set on the inner wall of the reinforcement pipe and grout outlet holes are evenly set on the outer wall of the reinforcement pipe. The lower end of the reinforcement pipe does not enter the shield excavation outline of the newly excavated tunnel. Special pipe segments are laid in the newly excavated tunnel at the position corresponding to the lower end of the reinforcement pipe. The special pipe segments are set with grooves. Through holes are opened at the bottom of the grooves. After several special pipe segments are ring-supported, a support groove is formed. A support ring is set in the support groove. A connector is installed on the side of the support ring closest to the reinforcing pipe. After the special pipe segments are laid, the anchor rod is inserted into the reinforcing pipe from top to bottom. The lower end of the anchor rod is connected to the connector. A pad assembly is installed at the bottom of the side of the support ring away from the reinforcing pipe.

[0007] Preferably, the support ring includes two arc-shaped rods, the lower ends of the two arc-shaped rods are hinged together, the upper end of each arc-shaped rod is hinged together with a support rod, the upper ends of the two support rods are provided with a hinge shaft, and a connector is provided on the hinge shaft.

[0008] Preferably, a limiting plate is provided at the upper end of the arc-shaped rod, and the limiting plate restricts the angle of upward rotation of the support rod.

[0009] Preferably, the pad assembly includes two symmetrically arranged inclined blocks, each inclined block having a through hole through which a screw is inserted. One end of the two screws is hinged together, and the other end of each screw is threaded with a nut. After the two inclined blocks move towards each other by pressing, the nuts press them together on the side of the inclined blocks to form a lock.

[0010] Preferably, the connector includes a ring, which is slidably connected to a hinge shaft, and the outer circle of the ring is hinged to a cylinder, which is threadedly connected to an anchor rod.

[0011] Preferably, a support ring is provided at the lower end of each of the two reinforcing tubes, and a tie rod is fixedly connected between the hinge axes of the two support rings.

[0012] This invention provides a grouting reinforcement device for stacked tunnels. It has the following beneficial effects: (1) Rotate the connector of the support ring to the corresponding position at the lower end of the reinforcing pipe. Insert the anchor rod downward into the reinforcing pipe. After the lower end of the anchor rod is fixedly connected to the connector, on the one hand, the anchor rod is pulled from above, so that the soft soil area consolidated by the reinforcing pipe is lifted obliquely upward to the existing tunnel, avoiding the subsidence caused by the existing tunnel pressing down on the soil between the newly excavated tunnel. On the other hand, when the support ring forms a ring structure and the pad block assembly is embedded at the corresponding point, the support ring applies a support top force to the soft soil area. Compared with the conventional reinforcing arch ring applying a uniform support force around the tunnel, its application... The added support force is directional (towards the soft soil area), and the stress structure of the support is more reasonable. The composite support method of pulling up and pushing down overcomes the defect that the existing tunnel above cannot be vertically reinforced due to the obstacles of the track bed and rails. It effectively copes with the unfavorable geological conditions in the vertical area and the local soft soil area. When a symmetrical pull-up and push-down support system is applied to both sides of the existing tunnel, the soil in the vertical area will be pushed by the support ring, and the reinforcement pipe will be subjected to the F-direction force. The area between the two inclined reinforcement pipes will be concentrated, thus making the reinforcement support effect of the vertical area stronger. Attached Figure Description

[0013] Figure 1This is a schematic diagram showing the soft soil area of ​​the present invention located obliquely above the newly excavated tunnel; Figure 2 This is a schematic diagram showing the soft soil area of ​​the present invention located directly above the newly excavated tunnel; Figure 3 This is a schematic diagram showing the state of the support rings folded together; Figure 4 yes Figure 3 A magnified view of a portion at point E; Figure 5 yes Figure 3 A magnified view of a portion at point F; Figure 6 This is a schematic diagram showing the support ring in its undeployed state; Figure 7 yes Figure 6 A magnified view of a portion at point H; Figure 8 This is a schematic diagram showing the unfolded state of the two support rings; Figure 9 yes Figure 8 A magnified view of a portion of point M. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0015] Example 1 Please see Figures 1 to 9This invention provides a technical solution: a grouting reinforcement device for a stacked tunnel, comprising an existing tunnel 10 and a newly excavated tunnel 20. The track bed and rails within the existing tunnel 10 obstruct the support construction of the newly excavated tunnel 20 below. Excavation zones are set up on both sides of the existing tunnel 10, with reinforcement walls 30 installed on the inner walls of these zones. A reinforcing pipe 1 is inserted obliquely into the newly excavated tunnel 20 from within the reinforcement walls 30. The lower end of the reinforcing pipe 1 falls into the area above the newly excavated tunnel 20, forming support. The reinforcing pipe 1 penetrates a soft soil area 40 identified by geological survey. A cavity is provided in the inner wall of the reinforcing pipe 1, and grout outlet holes are evenly distributed on the outer wall of the reinforcing pipe 1, extending outwards to the surrounding soil and soft soil area 40. The grouting reinforcement of the soil by injecting grout is an existing technology. The lower end of the reinforcement pipe 1 does not enter the shield excavation outline of the newly excavated tunnel 20, so as not to affect the cutting of the shield machine. Special pipe segments 2 are laid at the position corresponding to the lower end of the reinforcement pipe 1 in the newly excavated tunnel 20. The special pipe segments 2 are provided with grooves 21. Through holes 22 are opened at the bottom of the grooves 21. The through holes 22 are opened after the special pipe segments 2 are laid. The through holes 22 are channels for the anchor rods 5 to be inserted into the newly excavated tunnel 20 by using water drilling / cutting equipment. After several special pipe segments 2 are ring-supported, a support groove is formed. A support ring 3 is set in the support groove. The support ring 3 is in a folded state, which makes it easy to move to the support position in the newly excavated tunnel 20. A connector 4 is installed on the side of the support ring 3 near the reinforcing pipe 1. The reinforcing pipe 1 has a double-layer structure (the outer wall and the inner wall are interlayered with grout). The anchor rod 5 is inserted through the central channel. Grouting is performed from the interlayer of the inner wall of the reinforcing pipe 1 outward. After the special pipe segment 2 is laid, the anchor rod 5 is inserted from top to bottom into the reinforcing pipe 1. The anchor rod 5 is a multi-strand steel strand. The lower end of the multi-strand steel strand is a butt joint column. After the anchor forms the designed prestress, after tensioning, cement grout is injected into the central channel to anchor the steel strand inside the reinforcing pipe 1. The butt joint column at the lower end of the anchor rod 5 is connected to the connector 4 by welding or thread. A pad assembly 6 is installed at the bottom of the side of the support ring 3 away from the reinforcing pipe 1.

[0016] like Figure 1 As shown, the soft soil area 40 is located diagonally above the cross-section of the newly excavated tunnel 20. The support ring 3 is temporarily supported by a bracket 50. A rotating device (conventional construction machinery with rotational function) rotates the connector 4 of the support ring 3 to the position corresponding to the lower end of the reinforcing pipe 1. The reinforcing pipe 1 is then inserted downwards into the anchor rod 5. After the lower end of the anchor rod 5 is fixedly connected to the connector 4, on the one hand, the anchor rod 5 pulls from above, causing the soft soil area 40, which is consolidated by the reinforcing pipe 1, to be lifted diagonally upwards towards the existing tunnel 10, preventing subsidence caused by the existing tunnel 10 pressing down on the soil between the newly excavated tunnel 20. On the other hand, when the support ring 3 forms a ring structure and the pad assembly 6 is embedded at point B, the support ring 3 applies a support force to the soft soil area 40 through direction b. Compared to the conventional reinforcing arch ring which applies support force uniformly around the tunnel, the applied support force is directional (towards the soft soil area 40), making the force-bearing structure of the support more reasonable. Figure 2 As shown, the soft soil region 40 is located directly above the cross-section of the newly excavated tunnel 20. By embedding the pad assembly 6 at point B, the support ring 3 applies a supporting force to the soft soil region 40 along the d direction. This upward-pulling and downward-pushing method avoids the positional defects of the existing tunnel 10 being unable to vertically reinforce the vertical region 60 between the existing tunnel 10 and the newly excavated tunnel 20, and the local soft soil region 40. Figure 6 As shown, when a symmetrical pull-up and push-down support system is applied to both sides of the existing tunnel 10, the soil in the vertical region 60 will be pushed by the support ring 3, and the reinforcement pipe 1 will be subjected to the F-direction force. The area between the two inclined reinforcement pipes 1 will be concentrated, thus strengthening the reinforcement support effect on the vertical region 60.

[0017] Example 2 Figures 1 to 9 As shown, the support ring 3 includes two arc-shaped rods 31, with their lower ends hinged together. Each arc-shaped rod 31 has its upper end hinged to a support rod 32. A limiting plate 311 is provided at the upper end of each arc-shaped rod 31, restricting the upward rotation angle of the support rod 32. This allows the support rod 32 to form a rigid arc-shaped top-pressing profile after being limited in its upward rotation. The hinge point of the two support rods 32 is located inside the ring. When the hinge point of the two support rods 32 moves outward, the arc-shaped rods 31 are opened, facilitating movement in the folded state. When extended, they can extend into the groove 21 to form a ring support. A hinge shaft 33 is provided at the upper ends of the two support rods 32. A connector 4 is provided on the hinge shaft 33, and the connector 4 includes a ring 4. 1. The circular ring 41 is slidably connected to the hinge shaft 33 for easy position adjustment. The outer circle of the circular ring 41 is hinged to the cylinder 42, and the cylinder 42 is threadedly connected to the anchor rod 5. After connection, the anchor rod 5 is pulled upward, and the support rod 32 and the arc rod 31 unfold to form an arc-shaped support surface, which provides support to the soft soil area 40 along the direction of the anchor rod 5. The connector 4 is pulled upward by the anchor rod 5, and the connector 4 drives the hinge shaft 33 to move upward. The hinge shaft 33 pulls the two support rods 32 to rotate and spreads the two arc rods 31 until the limiting plate 311 abuts against the support rod 32, so that the support ring 3 changes from a folded state to an unfolded rigid ring support state. After unfolding and adjusting to the position, each hinge part can be spot welded to fix it to enhance the rigidity of the support ring.

[0018] Example 3 Figures 1 to 9As shown, a conventional pad is used, and a hydraulic jack is pressed into the pad position. Since the arc surface structure of the arc rod 31 is not easy to lock, in this embodiment, the pad assembly 6 includes two symmetrically arranged inclined blocks 61. Each inclined block 61 is provided with a through hole, and a screw 62 is inserted into the through hole. One end of the two screws 62 is hinged together, and the other end of each screw 62 is threaded to a nut 63. After the two inclined blocks 61 are pressed against each other, the nuts 63 press them on the side of the inclined blocks 61 to form a lock. The inclined blocks 61 on both sides are pushed by the hydraulic jack at the same time. Through the action of the inclined surface and the outer arc surface of the arc rod 31, the support ring 3 is pressed towards the anchor rod 5 as a whole. After being pressed to the predetermined requirement, the nuts 63 are locked, so that the support ring 3 forms the required directional pushing force.

[0019] Example 4 Figures 1 to 9 As shown, a support ring 3 is installed at the lower end of each of the two reinforcing pipes 1. A tie rod 7 is welded and fixedly connected between the hinge shafts 33 of the two support rings 3. The soil in the vertical region 60 is pushed by the support rings 3, and the reinforcing pipe 1 will be subjected to the F-direction force, thus reinforcing the vertical region 60 and preventing the subsidence of the pipe segments above the newly excavated tunnel 20. However, the anchor rod 5 provides an outward inclined pulling force, making Figure 8 The two support rings 3 shown tend to move away from each other. The two support rings 3 are connected as a whole by the tie rod 7 to avoid the expansion and contraction between two adjacent special tunnel segments 2 and to prevent water seepage from the top wall of the newly excavated tunnel 20.

[0020] Finally, the formwork is supported in the groove 21 and filled with concrete, the concrete is filled in the reinforced wall 30, and the support ring 3 is poured to form a reinforced whole.

[0021] The working principle of this invention is as follows: Utilizing the excavated areas on both sides of the existing tunnel 10 as operating space, the reinforcing pipe 1 is obliquely traversed through the soft soil area 40 and anchored above the newly excavated tunnel 20. The reinforcing pipe 1 is connected to the connecting piece 4 of the support ring 3 via anchor rods 5, and prestress is applied. This generates an oblique lifting force on the soft soil area 40 towards the existing tunnel, while simultaneously adjusting the jacking position of the pad assembly 6 at the bottom of the support ring 3 to generate a directional jacking force towards the soft soil area. This combined upward and downward force system, compared to the traditional ring support's center-pulling force mode, can specifically resist the downward transmission of the existing tunnel load through the soft soil area, effectively controlling the ground settlement in the vertical area 60.

[0022] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A grouting reinforcement device for a stacked tunnel, comprising an existing tunnel (10) and a newly excavated tunnel (20), wherein excavation zones are respectively set on both sides of the existing tunnel (10), and a reinforcement wall (30) is set on the inner wall of the excavation zone, and a reinforcement pipe (1) is drilled into the newly excavated tunnel (20) from the inside of the reinforcement wall (30) and inserted, wherein a cavity is set on the inner wall of the reinforcement pipe (1), and grout outlet holes are uniformly set on the outer wall of the reinforcement pipe (1), characterized in that: Special pipe segments (2) are laid at the lower end of the newly excavated tunnel (20) corresponding to the reinforcement pipe (1). The special pipe segments (2) are provided with grooves (21). Through holes (22) are opened at the bottom of the grooves (21). After several special pipe segments (2) are ring-supported, a support groove is formed. A support ring (3) is set in the support groove. A connector (4) is provided on the side of the support ring (3) close to the reinforcing pipe (1). After the special pipe segment (2) is laid, the reinforcing pipe (1) is inserted into the anchor rod (5) from top to bottom. The lower end of the anchor rod (5) is connected to the connector (4). A pad assembly (6) is provided at the bottom of the side of the support ring (3) away from the reinforcing pipe (1). The support ring (3) includes two arc-shaped rods (31), the lower ends of the two arc-shaped rods (31) are hinged together, the upper end of each arc-shaped rod (31) is hinged together with a support rod (32), the upper ends of the two support rods (32) are provided with a hinge shaft (33), and a connector (4) is provided on the hinge shaft (33). The pad assembly (6) includes two symmetrically arranged inclined blocks (61), each inclined block (61) is provided with a through hole, and a screw (62) is inserted into the through hole. One end of the two screws (62) is hinged together, and the other end of each screw (62) is threaded to a nut (63). After the two inclined blocks (61) are pressed against each other, the nut (63) presses them together to form a lock on the side of the inclined block (61).

2. The grouting reinforcement device for stacked tunnels according to claim 1, characterized in that: A limiting plate (311) is provided at the upper end of the arc-shaped rod (31), and the limiting plate (311) restricts the angle of upward rotation of the support rod (32).

3. The grouting reinforcement device for stacked tunnels according to claim 1, characterized in that: The connector (4) includes a ring (41), which is slidably connected to the hinge shaft (33). The outer circle of the ring (41) is hinged to the cylinder (42), and the cylinder (42) is threadedly connected to the anchor rod (5).

4. The grouting reinforcement device for stacked tunnels according to claim 1, characterized in that: A support ring (3) is provided at the lower end of each of the two reinforcing tubes (1), and a tie rod (7) is fixedly connected between the hinge shafts (33) of the two support rings (3).

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