Escape device of bentonite improving shield tunneling machine and construction method thereof

Abstract

The invention belongs to the technical field of shield tunnel construction, particularly relates to an escape device of a bentonite improving shield tunneling machine and a construction method. The escape device comprises an even number of jet grouting piles, wherein the jet grouting piles are three-pipe jet grouting piles, the pile forming diameter is 800-1000 mm, the specific number of the jet grouting piles is determined according to soil layer parameters and the cutterhead diameter of the shield tunneling machine, the jet grouting piles are located at the positions 400-500 mm away from the front of a cutterhead of the shield tunneling machine, jet grouting pile slurry is specially-prepared bentonite slurry, the mass ratio of bentonite to water to CMC to soda ash is 200 to 900 to 1 to 2, and the stratum which the structures of the jet grouting piles are applicable to is a dense sand layer. The construction method comprises the three steps: first step, the positions of the jet grouting piles are arranged; second step, the jet grouting pile slurry is prepared; third step, the bentonite slurry is rotary jet grouting for pile forming. The construction steps are simple, the escape problem of the shield tunneling machine in the dense sand layer can be effectively and quickly solved, a construction period is short, the construction cost is low, and good economic benefits are obtained.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a bentonite-improved soil body shield machine relief device and a construction method thereof, and is especially suitable for tunnel construction of a shield machine in a dense sand layer. Background technique [0002] At the beginning of this century, the construction of shield tunnels has been widely used in my country. However, due to the complex geological conditions in various regions of our country, the shield machine is often trapped during shield construction. In particular, when the shield machine is excavating in the dense sand layer, the muck around the cutter head and in the soil bin gradually loses water and deposits and consolidates around the cutter head due to long-term shutdown. The amount of deposition gradually increases with time, and the sand The porosity of the strata gradually decreases, and the binding force of the formation ...

AI Technical Summary

Problems solved by technology

[0002] At the beginning of this century, shield tunnel construction has been widely used in my country. However, due to the complex geological conditions in various regions of our country, shield tunneling often occurs during shield construction.

In particular, when the shield machine is excavating in the dense sand layer, the muck around the cutter head and in the soil bin gradually loses water and deposits and consolidates around the cutter head due to long-term shutdown. The amount of deposition gradually increases with time, and the sand The porosity of the strata gradually decreases, and the binding force of the formation to the cutterhead gradually increases, causing the muck to lock the cutterhead, and the starting torque is greater than the rated torque, resulting in the cutterhead being unable to rotate

The traditional methods to solve this kind of shield tunneling include opening the cabin in the hole, digging shafts after slotting on the ground, etc. However, these methods have a long construction period and high safety risks

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