Large-section tunnel circular blasting and tunnelling method

Abstract

The invention discloses a large-section tunnel circular blasting and tunnelling method. The large-section tunnel circular blasting and tunnelling method comprises the following steps that a segment of guiding tunnel is tunnelled in the middle of the bottom end of the tunnel face of a large-section tunnel in the extension direction of the large-section tunnel; guiding holes are punched in a plurality of cross sections of the guiding tunnel according to a certain depth in the radial direction, and the guiding holes are distributed in a fan shape along the guiding tunnel; a plurality of large-section perimeter holes are punched in edges of fan-shaped outlines formed by the distribution of the multiple guiding holes in the axial direction of the guiding tunnel; after the guiding holes and the large-section perimeter holes are detonated, a segment of the large-section tunnel is formed, a passage is shovelled out in the middle of the large-section tunnel, and the waste stones detonated and caved are shovelled to the two sides of the passage to be used for paving steps; and the segmented and circular construction is performed until the tunnelling work of the whole large-section tunnel is accomplished. By means of the large-section tunnel circular blasting and tunnelling method, the circular operation of large-section tunnel blasting and tunnelling is achieved, the tunnelling efficiency is improved, the vibration of blasting is greatly reduced, the safety of the tunnel construction is improved, the requirements for the drilling equipment are lowered, the working strength of the staff is lowered, and the drilling work efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of tunnel blasting and excavation, in particular to a method for circular blasting and excavation of a large-section tunnel. Background technique [0002] Since the 1960s, tunnel blasting and excavation technology has continued to improve and develop. From dry drilling to wet drilling, a large number of mechanized drilling rigs with good drilling quality and high efficiency have been developed; from fire detonator initiation and electric detonator initiation to plastic nonel detonation; from ordinary rock explosives For waterproof emulsion explosives. Although the performance of mechanical equipment and explosives used in tunnel excavation has made great progress, the technology of blasting excavation has basically remained unchanged. The cuttings are arranged according to the actual situation of the tunnel to assist the blasting of surrounding holes to break rocks. This method is widely used and has achie...

AI Technical Summary

Problems solved by technology

This method is widely used and has achieved good results when the tunnel section is small, but the effect is not ideal when excavating large-section tunnels. After a blast, it needs to go through shoveling of waste rock, slag removal, cleaning of the working face, drilling, etc. Only a complete set of procedures can proceed to the next stage of blasting work

Moreover, due to the large size of the section, the blasting effect of the traditional method is not ideal, and large seismic waves will also be generated.

In addition, there are still problems such as insufficient length of one blasting stage, high drilling cost, inability to realize circular excavation caused by blasting process, and long construction period.

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