Grouting reinforcement structure for controlling deformation of adjacent existing tunnel during tunneling of up-down overlapped tunnel

Abstract

The utility model discloses a grouting reinforcement structure for controlling deformation of an adjacent existing tunnel during tunneling of up-down overlapped tunnels, which comprises the existing tunnel and the overlapped tunnel, the existing tunnel and the overlapped tunnel are both positioned below the ground of a municipal main road, the existing tunnel is positioned on the upper left of the overlapped tunnel, and the overlapped tunnel comprises an upper tunnel and a lower tunnel. The lower-line tunnel surrounding grouting area is arranged outside the lower-line tunnel, and the upper-line tunnel surrounding grouting area is arranged on the section and the outside of the upper-line tunnel; the grouting straight hole 1, the grouting straight hole 2 and the grouting inclined hole all extend to the lower end of a grouting reinforcement area around the upper line tunnel from the ground; and the in-tunnel grouting pipe extends to the edge of a grouting reinforcement area around the off-line tunnel from the inside of the off-line tunnel. According to the reinforcing structure, grouting reinforcement is conducted on the peripheries of the upper line tunnel and the lower line tunnel in the mode of ground grouting and in-hole grouting, the influence of overlapped tunneling on the existing tunnel is reduced, and meanwhile ground surface settlement caused by tunneling can be reduced by conducting grouting reinforcement on soil layers around the tunnel.

Description

Technical Field

[0001] The utility model relates to a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation, belonging to the technical field of shield tunnel reinforcement. Background Art

[0002] Urban underground transportation networks are rapidly increasing and becoming increasingly complex. To save underground space, complex working conditions such as adjacent to existing tunnels and overlapping tunnels will inevitably arise. Most of the existing overlapping tunnels are reinforced by shield tail grouting during shield excavation, and the deformation control problem under the working conditions of adjacent existing tunnels is not considered.

[0003] Chinese utility model patent application number CN202321319252 discloses a reinforcement structure for overlapping tunnel excavation to prevent deformation of an adjacent existing tunnel, comprising an existing tunnel, an overlapping tunnel, a vertical grouting isolation area between the existing tunnel and the overlapping tunnel, a grouting reinforcement area close to the overlapping tunnel, a grouting pipe and the ground; the existing tunnel and the overlapping tunnel are both located at the lower end of the ground, the existing tunnel is located at the left end of the overlapping tunnel, the overlapping tunnel comprises an up tunnel and a down tunnel, the up tunnel is located at the upper end of the down tunnel, the grouting reinforcement area comprises a down tunnel grouting reinforcement area and an up tunnel grouting reinforcement area, the down tunnel grouting reinforcement area is arranged outside the down tunnel and in contact with the bottom of the vertical grouting isolation area, the up tunnel grouting reinforcement area is arranged outside the up tunnel and in contact with the middle of the vertical grouting isolation area; the grouting pipes are respectively arranged inside the up tunnel and the down tunnel and extend to the down tunnel grouting reinforcement area and the up tunnel grouting reinforcement area respectively. However, this technology has the following disadvantages:

[0004] 1. There is a municipal trunk road between the existing tunnel and the overlapping tunnel. It is difficult to have sufficient space for construction in the vertical grouting isolation area between the existing tunnel and the overlapping tunnel.

[0005] 2. The distance between the existing tunnel and the overlapping tunnel is small, making it difficult to grout the grouting isolator. The grouting diffusion is highly random, which may affect the adjacent existing tunnel. In addition, the thickness of the grouting isolator is inevitably limited by the distance between the existing tunnel and the overlapping tunnel. Utility Model Content

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during tunneling of upper and lower overlapping tunnels, characterized in that it includes a municipal trunk road, an existing tunnel, an overlapping tunnel, a grouting reinforcement area around the upper line tunnel, a grouting reinforcement area around the lower line tunnel, a grouting pipe in the tunnel, a grouting straight hole 1, a grouting straight hole 2, a grouting inclined hole and the ground; the municipal trunk road is located between the existing tunnel and the overlapping tunnel, the existing tunnel and the overlapping tunnel are both located below the ground, the existing tunnel is located to the upper left of the overlapping tunnel, the overlapping tunnel includes an upper line tunnel and a lower line tunnel, the upper line tunnel is located above the lower line tunnel, the grouting reinforcement area around the lower line tunnel is arranged outside the lower line tunnel, and the grouting reinforcement area around the upper line tunnel is arranged on the section and outside of the upper line tunnel; the grouting straight hole 1, the grouting straight hole 2 and the grouting inclined hole all extend from the ground to the lower end of the grouting reinforcement area around the upper line tunnel; the grouting pipe in the tunnel extends from the lower line tunnel to the edge of the grouting reinforcement area around the lower line tunnel.

[0007] Furthermore, the existing tunnel has a double-line parallel structure.

[0008] Furthermore, the grouting reinforcement area around the upper line tunnel is a rectangular structure, and the grouting reinforcement area around the lower line tunnel is a 3 / 4 circular structure.

[0009] Furthermore, grouting straight hole 1, grouting straight hole 2 and grouting inclined hole are drilled from the ground outside the municipal main road, with one section every 1.5m, and 3 grouting holes are arranged in each standard section; the grouting pipes in the tunnel are drilled from the downline tunnel, and 8 grouting pipes are arranged at equal intervals in each standard section.

[0010] Furthermore, the depth of the grouting reinforcement area around the upper-line tunnel ranges from 5m below the ground to 1m below the arch bottom of the upper-line tunnel, and the width is twice the diameter of the upper-line tunnel; the outer diameter of the circular ring of the grouting reinforcement area around the lower-line tunnel is the same as the radius of the lower-line tunnel.

[0011] Furthermore, sleeve valve pipes with a diameter of 38 mm and a wall thickness of 3 mm are used in the grouting pipes, grouting straight hole 1, grouting straight hole 2 and grouting inclined holes in the tunnel, and double-liquid slurry is injected for reinforcement using the ZLJ-350B integrated grouting machine.

[0012] The beneficial effects of the utility model are:

[0013] Grouting reinforcement around overlapping tunnels can make the soil around the tunnels have higher strength and a certain water-isolating effect, effectively reducing the impact of overlapping tunnel excavation on existing tunnels and ensuring the safety of existing tunnels; at the same time, grouting reinforcement around overlapping tunnels improves the strength of the surrounding soil, thereby reducing surface settlement caused by shield excavation. Compared with the existing overlapping tunnel reinforcement method adjacent to the existing tunnel, the utility model performs grouting reinforcement around the overlapping tunnel by jointly setting grouting holes on the ground and in the downline tunnel, avoiding the problem of inconvenience in construction of the grouting area under the municipal main road, and using two grouting methods can avoid the impact on the existing tunnel, ensuring a sufficiently large reinforcement area, so that the reinforcement body reaches sufficient strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a schematic diagram of a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation.

[0015] In the figure, 1-municipal main road, 2-existing tunnel, 3-overlapping tunnel, 301-upper-line tunnel, 302-lower-line tunnel, 4-grouting reinforcement area around upper-line tunnel, 5-grouting reinforcement area around lower-line tunnel, 501-grouting pipe in the tunnel, 6-grouting vertical hole 1, 7-grouting vertical hole 2, 8-grouting inclined hole, 9-ground. DETAILED DESCRIPTION

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings.

[0017] Reference Figure 1 The utility model provides a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during excavation of upper and lower overlapping tunnels, comprising a municipal trunk road, an existing tunnel, an overlapping tunnel, a grouting reinforcement area around the upper line tunnel, a grouting reinforcement area around the lower line tunnel, a grouting pipe in the tunnel, a grouting straight hole 1, a grouting straight hole 2, a grouting inclined hole and the ground; the municipal trunk road is located between the existing tunnel and the overlapping tunnel, the existing tunnel and the overlapping tunnel are both located below the ground, the existing tunnel is located to the upper left of the overlapping tunnel, the overlapping tunnel comprises an upper line tunnel and a lower line tunnel, the upper line tunnel is located above the lower line tunnel, the grouting area around the lower line tunnel is arranged outside the lower line tunnel, and the grouting area around the upper line tunnel is arranged outside the upper line tunnel; the grouting straight hole 1, the grouting straight hole 2 and the grouting inclined hole all extend from the ground to the lower end of the grouting reinforcement area around the upper line tunnel; the grouting pipe in the tunnel extends from the lower line tunnel to the edge of the grouting reinforcement area around the lower line tunnel.

[0018] Furthermore, the existing tunnel has a double-line parallel structure.

[0019] Furthermore, the grouting reinforcement area around the upper line tunnel is a rectangular structure, and the grouting reinforcement area around the lower line tunnel is a 3 / 4 circular structure.

[0020] Furthermore, grouting straight hole 1, grouting straight hole 2 and grouting inclined hole are drilled from the ground outside the municipal main road, with one section every 1.5m, and 3 grouting holes are arranged in each standard section; the grouting pipes in the tunnel are drilled from the downline tunnel, and 8 grouting pipes are arranged at equal intervals in each standard section.

[0021] Furthermore, the depth of the grouting reinforcement area around the upper-line tunnel ranges from 5m below the ground to 1m below the arch bottom of the upper-line tunnel, and the width is twice the diameter of the upper-line tunnel; the outer diameter of the circular ring of the grouting reinforcement area around the lower-line tunnel is the same as the radius of the lower-line tunnel.

[0022] Furthermore, sleeve valve pipes with a diameter of 38 mm and a wall thickness of 3 mm are used in the grouting pipes, grouting straight hole 1, grouting straight hole 2 and grouting inclined holes in the tunnel, and double-liquid slurry is injected for reinforcement using the ZLJ-350B integrated grouting machine.

[0023] The utility model provides a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation. Grouting is performed around the upper tunnel and the lower tunnel to form a surrounding grouting area to control deformation of the adjacent existing tunnel. Two straight grouting holes and one inclined grouting hole are drilled into the soil on the ground above the overlapping tunnel. At the same time, a grouting pipe is also drilled in the lower tunnel. A rectangular reinforcement area is formed around the upper tunnel and a 3 / 4 circular reinforcement area is formed around the lower tunnel. This reduces the impact of shield tunnel excavation on the existing tunnel and the impact of the upper tunnel excavation on the lower tunnel.

[0024] The utility model provides a grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation, and the steps are as follows:

[0025] Step 1, construction of overlapping tunnel 3:

[0026] Choose two The composite earth pressure balance shield machine adopts the order of "first up and then down" for excavation. In the area where the construction of the lower line tunnel is completed, in-hole grouting is used to construct the grouting reinforcement area 5 around the lower line tunnel. After the lower line tunnel 302 is excavated 100m, the ground advance pre-grouting is used to reinforce the soil in the excavation range of the upper line tunnel to form the grouting reinforcement area 4 around the upper line tunnel. Then the excavation of the upper line tunnel 301 begins.

[0027] Step 2: Grouting reinforcement area 5 around the offline tunnel:

[0028] After the shield tunneling machine (TBM) in the lower tunnel 302 completed segment assembly and synchronized grouting for a certain distance, secondary grouting began through the shield segments, using grouting pipes 501 drilled into the tunnel. Eight grouting holes were reserved for each standard section, arranged in a circular pattern, with an angle of 22.5° between adjacent holes. A hydraulic drill was used for drilling, and sleeve-valve pipes with a diameter of 38mm and a wall thickness of 3mm were used for the grouting. The grouting slurry used was 42.5-grade Portland cement with a water-cement ratio of 1:1. 2.4% to 3.4% water glass was added during grouting, with a concentration of 30 to 45° Baume. Grouting pressure was generally controlled within 0.5 MPa. If a section contained more soil and rock layers, the maximum grouting pressure could be limited to no more than 0.8 MPa. The grouting flow rate was controlled at 10 to 20 L / min.

[0029] Step 3: Grouting reinforcement area 4 around the tunnel

[0030] Grouting reinforcement area 4 around the upper tunnel was carried out using a combination of straight and inclined holes. A ZLJ-350B integrated grouting machine was used to inject dual-liquid slurry for reinforcement. The grouting sequence was first on both sides of the tunnel, followed by the centerline. After the completion of grouting reinforcement area 5 around the lower tunnel, a hydraulic drill was used to drill holes on the auxiliary road of the municipal main road 1. During the drilling process, to prevent the drill rod from locking and the drill bit from clogging the grouting holes, a grouting pump was used to continuously inject small amounts of cement slurry to protect the walls and punch the holes. Once the grouting system was ready, the grouting pipe was connected to the drill rod and grouting began. When the designed grouting volume was reached at a height of approximately 0.75m or the pressure reached the designed value, grouting was paused, the drill rod was raised halfway (approximately 0.75m), and the above process was repeated until the tunnel was completely filled. The grouting depth was 1m to the tunnel bottom, ranging from 21.5m to 31.5m.

Claims

1. A grouting reinforcement structure for controlling deformation of adjacent existing tunnels during overlapping tunneling, characterized by: It includes a municipal trunk road (1), an existing tunnel (2), an overlapping tunnel (3), a grouting reinforcement area around the upper tunnel (4), a grouting reinforcement area around the lower tunnel (5), a grouting pipe in the cave (501), a grouting straight hole 1 (6), a grouting straight hole 2 (7), a grouting inclined hole (8) and the ground (9); The municipal trunk road (1) is located between the existing tunnel (2) and the overlapping tunnel (3), the existing tunnel (2) and the overlapping tunnel (3) are both located below the ground (9), the existing tunnel (2) is located on the upper left of the overlapping tunnel (3), the overlapping tunnel (3) includes an upper tunnel (301) and a lower tunnel (302), the upper tunnel (301) is located above the lower tunnel (302), a grouting reinforcement area (5) around the lower tunnel is set outside the lower tunnel (302), and a grouting reinforcement area (4) around the upper tunnel is set on the cross section and outside of the upper tunnel (301); The grouting straight hole 1 (6), the grouting straight hole 2 (7), and the grouting inclined hole (8) all extend from the ground (9) to the lower end of the grouting reinforcement area (4) around the upper tunnel, and the grouting pipe (501) in the cave extends from the lower tunnel (302) to the edge of the grouting reinforcement area (5) around the lower tunnel.

2. The grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation according to claim 1 is characterized in that: The existing tunnel (2) is a double-line parallel structure.

3. The grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation according to claim 1, characterized in that: The grouting reinforcement area (4) around the upper tunnel is a rectangular structure, and the grouting reinforcement area (5) around the lower tunnel is a 3 / 4 circular structure.

4. The grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation according to claim 1, characterized in that: Grouting straight hole 1 (6), grouting straight hole 2 (7) and grouting inclined hole (8) are drilled from the ground (9) outside the municipal main road (1), with one section every 1.5m, and 3 grouting holes are arranged in each standard section; the grouting pipe (501) in the cave is drilled from the downline tunnel (302), and 8 grouting pipes are arranged at equal intervals in each standard section.

5. The grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation according to claim 1, characterized in that: The depth of the grouting reinforcement area (4) around the upper tunnel is from 5m below the ground to 1m below the arch bottom of the upper tunnel (301), and the width is twice the diameter of the upper tunnel (301); the outer diameter of the circular ring of the grouting reinforcement area (5) around the lower tunnel is the same as the radius of the lower tunnel (302).

6. The grouting reinforcement structure for controlling deformation of adjacent existing tunnels during upper and lower overlapping tunnel excavation according to claim 1, characterized in that: The grouting pipe (501), grouting straight hole 1 (6), grouting straight hole 2 (7) and grouting inclined hole (8) in the cave all use sleeve valve pipes with a diameter of 38 mm and a wall thickness of 3 mm, and are reinforced by injecting double liquid slurry using a ZLJ-350B integrated grouting machine.

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