基于改进局部安全度的爆破作用边坡稳定性分析

Stability analysis of slope affected by blasting based on improved local safety method

由于边坡滑动是渐进破坏的过程,研究其局部安全程度有重要意义。建立了改进的局部安全度(ZSI)计算方法,可统一表征局部岩土体弹性、塑性和破坏不同阶段的稳定状态,通过静力边坡的离心加载数值试验分析,验证了ZSI指标有效性。对爆破影响的边坡进行时程动力数值模拟,获得了不同爆破参数下边坡局部安全指标分布模式。结果表明,随着爆破荷载幅值、孔隙水压和荷载作用时间的增加,ZSI的负值区域逐渐增大,滑动面也不断延伸和贯通;振速增大区局部集中在滑动体,破坏区域主要集中在爆源附近和滑动面;爆破作用下孔隙水压对边坡滑动面破坏影响最为明显,而爆破作用时间对边坡爆源附近破坏影响最为明显。文中研究方法和结论对于深入认识爆破作用边坡的渐进破坏机制有积极的意义。

Because of the progressive damage of slope slip,it is significant to study the local safety degree of the slope.In this paper an improved method on calculating the local zone safety index(ZSI)is established to describe the stability state of local rock and soil mass at different stages of elastic,plastic and damage.studied the safety degree space distribution of slope by dynamic time-history numerical simulation.Based on the numerical tests of the centrifuge loading on the static slope,the rationality of the improved local zone safety index is verified.The time-history dynamic numerical simulation of the slope affected by blasting is carried out,and the distribution modes of local safety index of slope under different blasting parameters are obtained.The results show that with the increase of blasting load,pore water pressure and blasting action time,the negative area of ZSI at the slope also increases and the sliding surface is extending.The velocity increase zone is located at the sliding body,the damage zones are mainly located at the regions affected by blasting activity and sliding zones.The slope sliding surface is obviously affected by pore water pressure under the blasting action.The blasting action time obviously affects the damage zone near explosion source.The method and conclusions from this paper is meaning for understanding the mechanism of slope progressive destroy with blasting effects.