爆破开挖扰动作用下深埋隧洞的微震分布规律

基于地应力高、开挖断面大、日炮次多、爆破扰动强的施工环境下的微震监测数据，研究了爆破开挖扰动作用下深埋隧洞的微震分布规律.结果表明:爆破开挖卸荷影响范围内的微震活动既与围岩应力重分布有关，又与爆破扰动密不可分；爆破扰动是开挖卸荷影响范围之外微震活动的主要诱因，是时滞型岩爆孕育发生的重要影响因素之一；微震分布区域与爆破地点的相对位置及距离密切相关.研究结果可为钻爆法开挖下的隧洞岩爆防治提供参考.

Microseismic Event Distribution in Deep Tunnels Under the Disturbance of Blasting Excavation

Based on the monitored microseismic data in situations with high geo stress， large diameter， frequent daily blasting and strong blasting disturbance， the distribution of microseismic events occurring in the deep tunnels of JinpingⅡhydropower station under the action of blasting disturbance was investigated. The results show that the microseismic activities in the areas affected by excavation unloading are closely related to surrounding rock stress redistribution and blasting disturbance. And blasting disturbance is a main factor of triggering microseismic activities outside the influence range of excavation unloading; hence it is one of important factors for triggering the time delayed rockburst. Moreover， the distribution area of microseismic events is associated with its distance from the sites where blasting events happen and the relative location between them. The results achieved can provide the reference for the rockburst prevention during deep tunnel excavation by drill and blast technique.