Blasting Vibration Reduction Construction Method of Multiple Pilot Tunnel and Preset Composite Vibration Isolation Layer Close to Tunnel

Abstract

The invention relates to a blasting and vibration reduction construction method of a multiple pilot tunnel and a preset composite vibration isolation layer close to a tunnel, and belongs to the technical field of controlled blasting of short-distance intersecting tunnels. The present invention comprises the following steps: S1: first build the design of the composite vibration-isolation layer of the tunnel, S2: first build the pre-paving of the tunnel composite vibration-isolation layer, S3: build the tunnel later and prepare for the primary blasting, S4: build the tunnel composite pilot tunnel later S5: Preparation before the secondary blasting of the later-built tunnel, S6: Secondary blasting of the composite pilot tunnel of the later-built tunnel, S7: Grouting of the sand vibration-isolation layer in the first-built tunnel. The invention avoids the high peak vibration velocity generated when the cutting blast creates the air surface through the excavation structure of the face of the multiple guide tunnel, and can effectively reduce the blasting vibration velocity; The tradition of vibration isolation with a single layer of material makes the vibration isolation effect more significant; the combination of multiple pilot tunnels and pre-laid vibration isolation layer measures forms a blasting vibration reduction method that combines active vibration isolation and passive vibration reduction.

Description

technical field [0001] The invention relates to a blasting and vibration reduction construction method of a multiple pilot tunnel and a preset composite vibration isolation layer close to a tunnel, and belongs to the technical field of controlled blasting of short-distance intersecting tunnels. Background technique [0002] The traditional method of blasting excavation by simply using reasonable control of blasting delay uses a non-electric millisecond detonator. Because the delay method is realized by controlling the burning speed of chemical agents, the error is very large due to the influence of the technology level. Under certain circumstances, the detonators of adjacent segments are easy to detonate at the same time, resulting in a large vibration peak. If it adopts an electronic detonator, there are also shortcomings such as the calculation method is not clear, and the price and technical requirements are high. [0003] The current research shows that the maximum blas...

AI Technical Summary

Problems solved by technology

[0004] (1) The current cutting blasting is basically oblique wedge-shaped cutting blasting. Although the peak value of the maximum vibration velocity has been reduced to a large extent, the maximum peak value of the blasting still occurs during the cutting blasting process. The reason has not been changed. Due to the lack of free face, it is adversely affected by the sandwiching effect of the surrounding rock on the face of the tunnel; (2) Although the traditional mechanical cutting blasting method effectively avoids the vibration peak generated by the cutting blasting, it does not make the leading small pilot hole The effect of creating the free surface is fully exerted, and there is still room for further vibration reduction; (3) The method of mechanical pre-cutting to create the blasting free surface greatly reduces the construction efficiency, and the pre-cutting machine cannot be applied to relatively hard surrounding rock , the cost of mechanical equipment is high and it is not universal; (4) The shock-absorbing blasting of the post-construction tunnel adopts the method of laying a vibration-isolation layer at the bottom of the over-excavated tunnel. (5) The non-blasting method of static crushing requires a pre-grooving machine to cut grooves multiple times and cooperate with static crushers and chemical effect crushing, which has high technical requirements and low construction efficiency

[0005] Although the above current cutting blasting method reduces the blasting vibration velocity to a certain extent, it creates limited free space and sacrifices construction efficiency.

Images