Analysis and Research on Safety Performance Parameters of Tunnel Blasting Based on 3-D Model Calculation and Computer Intelligent Modified Time History Method

Abstract

Blasting will produce vibration and noise, which will have an adverse impact on the surrounding environment such as residence, office and precision instruments. The impact analysis of blasting on adjacent structures has become an important content of environmental impact assessment of tunnel and subway construction. The evaluation of blasting impact through numerical analysis before construction is helpful to determine reasonable and economic construction methods and anti vibration measures. In this paper, the 3-D model calculation and computer intelligent modified time history method is used to establish a three-dimensional numerical model to analysis the impact of blasting on the adjacent tunnel when the high slope of the stockyard of the cement plant is excavated by blasting. Aiming at the shallow buried hard granite stratum, this paper analyzes the monitoring data of tunnel blasting vibration results, systematically studies the correlation between the maximum surface vibration velocity, the maximum single sound charge and the main frequency distribution under the construction condition of drilling and blasting method, and determines the maximum single sound charge in blasting construction through the comparative calculation of different charge quantities. The main research conclusions are as follows: the vertical vibration velocity is the largest in the process of tunnel blasting, and the vibration velocity decays exponentially with the increase of propagation distance. In order to avoid the resonance between the rock stratum and the tunnel structure as a whole, the simultaneous initiation of multiple detonators should be avoided, and the maximum single shot charge should be strictly controlled.