基于时程分析的滑塌式危岩清除爆破动力稳定性计算方法  

Dynamic stability calculation method for unstable sliding rock under excavation blasting based on time history analysis

作　　者：陈洪凯[1] 周云涛[1] 唐红梅[1] 

机构地区：[1]重庆交通大学岩土工程研究所,重庆400074

出　　处：《振动与冲击》2014年第15期31-34,41,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金(11272185)

摘　　要：针对滑塌式危岩清除爆破问题,通过爆破峰值速度衰减规律及危岩体力学特性,建立了滑塌式危岩动力物理模型及动力计算模型;通过欧拉方程确定危岩体内任一位置的爆破动应力,提出一种简化方法确定了爆破等效荷载,并对等效荷载进行动力时程修正,结合极限平衡方法得到危岩体任一时刻的稳定性系数,最终建立了滑塌式危岩动力计算方法。以重庆市望霞W2-1危岩体为例,作危岩稳定性系数时程曲线进行时程分析,分析结果表明,爆破动力作用致使稳定性系数降低2.86%,加剧了危岩体的危险性,爆破动力对危岩体的作用时间在0.45 s左右,与现场监测数据基本吻合,可为危岩动力稳定性计算评价及优化危岩爆破清除设计提供理论依据。Physical model of unstable sliding rock and dynamic calculation model for unstable sliding rock under excavation blasting were established with the blasting peak velocity decay law and the mechanical characteristics of unstable rock mass. Blasting dynamic stress at any position in the unstable rock was determined with Euler equation. A simplified method was proposed to obtain a blasting equivalent load and the equivalent load was modified with dynamic time-histories. Combining with the ultimate equilibrium method,the stability coefficient of unstable rock was gained at any moment. In the end,the dynamic calculation method of unstable sliding rock was built. Taking Wangxia W2-1 unstable rock of Chongqing as an example,the time history curve of unstable rock stability coefficient was drawn. It was shown that the dynamic effect of blasting causes the stability coefficient to drop by 2. 86% to increase the danger of unstable rock; the action time of blast power on the unstable rock is about 0. 45 s,it is coincident with the data of field monitoring; the proposed method provides a theoretical foundation for assessing the calculation of unstable rock stability and optimizing the design of excavation blasting.

关 键 词：动力地质学 动力稳定性计算方法 简化方法 时程分析 动荷载 危岩 

分 类 号：P512.5[天文地球—地质学] TU457[建筑科学—岩土工程]