Construction method for passing through muddy loose tunnel collapse body

Abstract

The invention belongs to a construction method for passing through a muddy loose tunnel collapse body. The construction method comprises the following steps that a plurality of steel bars distributedat intervals are driven forwards and obliquely along a tunnel excavation contour line to form a steel bar net shed; grouting guide pipes or grouting guide pipes and grouting long steel pipes which arealternately arranged are horizontally driven forwards along the steel bar net shed driven along the tunnel excavation contour line; and grouting consolidation is carried out on soil in front of a tunnel through the driven grouting guide pipes or grouting long steel pipes to form an annular belt-shaped grouting consolidation arch for protecting the tunnel or form a canine convex annular belt-shaped grouting consolidation arch, and support is provided for tunnel excavation and support. The construction method can quickly pass through the muddy loose tunnel collapse body at low cost and has theadvantages of being low in construction cost, short in construction period and low in safety risk.

Description

technical field [0001] The invention belongs to a construction method for passing through a muddy loose tunnel collapse body. Background technique [0002] At present, the tube shed method and advanced conduit are mostly used in the construction of tunnels with muddy loose structures. The pipe shed method is a pre-support method used to support the collapse of the tunnel face and limit the deformation of the surrounding rock during tunnel excavation. Lay steel pipes, usually with a diameter of 70-180mm and a length of 20-50m, and the distance between two adjacent steel pipes is 0.1-0.3m, and the steel pipes can be used to inject grout into the surrounding rock to reinforce the surrounding rock around the pipe shed, so that the pipe shed It becomes the protective shed for the subsequent excavation of the tunnel to achieve the purpose of safe construction. Its disadvantages are that the pre-supported steel pipes are embedded in the soil and cannot be recycled, the constructio...

AI Technical Summary

Problems solved by technology

The pipe shed method is a pre-support method used to support the collapse of the tunnel face and limit the deformation of the surrounding rock during tunnel excavation. Lay steel pipes, usually with a diameter of 70-180mm and a length of 20-50m, and the distance between two adjacent steel pipes is 0.1-0.3m, and the steel pipes can be used to inject grout into the surrounding rock to reinforce the surrounding rock around the pipe shed, so that the pipe shed It becomes the protective shed for the subsequent excavation of the tunnel to achieve the purpose of safe construction. Its disadvantages are that the pre-supported steel pipes are embedded in the soil and cannot be recycled, the construction cost is high, the preparation period for construction conversion is long, and the construction period is long. Special equipment needs to be added. The purchase cost of the pre-supported steel pipe machine is high

[0003] The advanced conduit is similar to the advanced anchor rod, which is also horizontally driven into the conduit along the set position outside the tunnel excavation contour line. The distance between the pipes is less than 40cm, and the grouting holes are reserved on the pipe wall. After the grouting cover of the pipe mouth, the cement slurry is injected, and the pressure grouting penetrates into the larger sandy soil around the diffusion pipe, and the grouting consolidation around the pipe forms a tunnel with a certain thickness. After the ring is reinforced, the purpose of safe construction is achieved. The process is simple and the cost is low. The disadvantage is that the one-time construction distance is short, the pre-supporting steel is small, and the formation pressure is high, and the formation displacement control is strict, so it is difficult to apply.

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