Drilling and blasting construction method for mechanized full-cross-section quick excavation and ring formation of weak surrounding rock tunnel

Abstract

The invention discloses a drilling and blasting construction method for mechanized full-cross-section quick excavation and ring formation of a weak surrounding rock tunnel. The construction method comprises the following steps of 1, advance pre-reinforcement of a tunnel face; 2, excavation of the tunnel face, wherein the tunnel face is subjected to mechanized drilling, powder charging and blastingexcavation, during drilling, except an inverted arch, the tunnel face is drilled in a mode of straight hole blasting, the inverted arch is drilled through a technology of postposition-free inverted arch primary support and bottom hole and slant hole blasting, bottom hole and slant hole drilling is downwards conducted in the tunneling direction, the mode of combining long and short holes is adopted, the long hole lifting height is increased, and tunnel overexcavation is controlled; outer-insertion short holes are adopted, and tunnel bottom under-excavation is controlled. Full-cross-section excavation is adopted, a cross section is subjected to one-time excavation forming, the repetitive operation time of working procedures is shortened, construction organization and management are facilitated, the labor condition is improved, and the work efficiency is high.

Description

technical field [0001] The invention relates to a construction method, more specifically to a construction method of rapid excavation of a ring-drilled hole blasting in a mechanized full-section of a tunnel with soft surrounding rock, and belongs to the technical field of tunnel construction. Background technique [0002] At present, with the rapid development of my country's high-speed rail, breakthroughs have been made in the development of tunnel engineering. With the pace of mechanized construction, newly excavated tunnels generally adopt mechanized primary support to protect the newly excavated free face and prevent the continuous development of surrounding rock deformation and damage. [0003] The traditional excavation method of micro-steps with three steps, upper and lower steps, and mechanized operations divides the excavation of the face into 2 to 3 areas for drilling and blasting, which easily leads to large settlement and deformation; and because the traditional ...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of the traditional excavation method, which easily lead to large settlement deformation and cannot be better applied to large-scale mechanized operations, etc., to provide a kind of rapid excavation of tunnels with weak surrounding rocks into ring drilling blasting construction with mechanized full-section construction method

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