Circular divided blasting tunnel construction method capable of effectively controlling blasting vibration velocity

Abstract

The invention discloses a circular divided blasting tunnel construction method. According to the method, a circular divided blasting manner that the periphery (an upper step portion, a side wall portion and an arch bottom portion) is blasted firstly, and then, a circular middle portion (a central rock stratum portion) is blasted is creatively adopted in the method. According to the method, the blasting safety distance from a surface building is lengthened, the maximum single-segment explosive payload is reduced, and the disturbance to a surrounding rock and the surface building is reduced; and meanwhile the method reduces a rock mass area of blasting each time, shortens work time of each divided portion and is beneficial to stability of a preliminarily-supported structure. Although the number of divided portions is increased, a work surface is increased at the same time, and it can be ensured that devices like a small-type excavator can enter a tunnel face to carry out operation. All the divided portions can be constructed synchronously, the work efficiency is improved, and the construction progress is quickened.

Description

technical field [0001] The invention relates to a tunnel construction method, in particular to a ring-directed staged blasting tunnel construction method capable of effectively controlling the blasting vibration velocity. Background technique [0002] At present, my country's subway and tunnel construction is at its peak. During the construction of the shallow buried section in the city, the surrounding environment is generally more complicated, and the blasting vibration has a greater impact on the construction area, which is likely to cause "disturbance" and "disturbance". In order to reduce the impact of blasting construction on the surrounding environment, it is necessary to give reasonable control indicators for blasting vibration. To control the vibration velocity, it is not only necessary to strictly adhere to the direction of minimizing the amount of charge in a single stage, but also to control the blasting vibration through a comprehensive differential method insi...

AI Technical Summary

Problems solved by technology

However, in the construction of shallow buried controlled blasting, due to the large blasting section, complex blasting network, and complicated cutting forms, etc., it is easy to cause the blasting vibration speed to exceed the standard or the amount of charge is insufficient to cause under-blasting, and it is difficult to achieve the ideal controlled blasting effect.

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