A blasting treatment method for boulders in front of the shield cutter head

Abstract

The invention discloses a boulder blasting treatment method used before operation of a cutter head of a shield tunneling machine. The method comprises following steps that S1, the position 6000 mm infront of the cutter head of the shield tunneling machine serves as the boundary line, the range away from the cutter head by within 6000 mm is divided as the primary blasting treatment area, and the range away from the cutter head by more than 6000 mm is divided as the subsequent blasting treatment area; S2, blasting holes are formed; S3, explosives are contained in the blasting holes; and S4, blasting begins. The blasting area is divided into the primary blasting treatment area and the subsequent blasting treatment area, in the primary blasting treatment area nearby the cutter head, the holedistribution amount is increased, the explosive amount in each blasting hole is reduced, through the manner of staggering the blasting time of the blasting holes, the problem of too large one-time blasting energy is solved, and the phenomenon that energy generated by one-time blasting is too large, and the shield tunneling machine is affected is avoided.

Description

technical field [0001] The invention relates to the technical field of shield tunneling excavation, in particular to a blasting treatment method for boulders in front of a shield cutter head. Background technique [0002] In the granite-developed strata, there are spherical weathered bodies of granite (commonly known as boulders) in the tunnel section. In the project, the boulders are usually found in the survey stage, and then the boulders are processed by manual excavation piles, rotary cores, drilling and blasting, etc., and then the shield is excavated to pass through. In actual engineering, surveys often fail to find all the boulders, and there must be fish that slip through the net. As a result, the existence of boulders is not discovered until the cutter head touches the rock mass during shield excavation. The granite rock mass with good integrity is strong, and it is undoubtedly the best choice to use "gunpowder" to break the rock mass. However, the blasting treatme...

AI Technical Summary

Problems solved by technology

If the boulder mass is large, the cost of direct excavation of the shield tunneling is high. In the project, a rock splitter is used to split the boulder rock mass after it enters the warehouse under pressure. This method is risky to carry out operations under pressure 1. The efficiency is low. Second, the integrity of the boulder is good and there is no free surface. The splitting effect of the rock splitter cannot meet expectations, and the rock splitter is expensive.

In addition, the project also tried to drill holes in the lone rock mass after being pressed into the warehouse to reduce the integrity of the rock mass, and then tunneled through the shield. The final result of this method was that the rock mass formed sharp stone knives, which caused the shield The damage to the structural tool is more serious, and the rock blocks cut during the excavation process are large in size and cannot be discharged due to accumulation in the warehouse

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