爆破作用下顺层岩质边坡稳定的可靠性分析

基于可靠度理论建立顺层岩质边坡稳定的可靠性分析方法,获得顺层岩质边坡可靠指标和失稳概率的计算表达式。以某高切坡为例分析其稳定状态和失稳概率,并据此探讨不同粘聚力、内摩擦角、炸药量和爆心距条件下边坡失稳概率的变化规律。计算结果表明,粘聚力对边坡的失稳概率影响较大;随着内摩擦角的增加,边坡失稳概率近乎线性减小;当单孔药量从10 kg增大到160 kg后,失稳概率增幅97.10%;当爆心距小于20 m时,边坡的失稳概率减小的速度很快,而爆心距超过20 m后边坡失稳概率减小的幅度较小。考虑爆破振动的时效性,爆破荷载使边坡失稳概率增大49.61%,单次爆破振动的影响时间约6 s。

Stability and Reliability Analysis of Bedding Rock Slope under Blasting

Based on reliability theory, a reliability analysis method for bedding rock slope is established, considering the effect of blasting load. The calculation expressions of the reliable index and failure probability are obtained. Taking a high-cutting slope as an example, the steady state and failure probability are analyzed, and the change rules of failure probability are discussed under diverse cohesion, internal friction angle, explosive charge and distance to burst center. The calculated results show that cohesion has a great influence on failure probability, and that failure probability decreases linearly with the increase of internal friction angle. When the single-hole dose increases from 10 kg to 160 kg, the failure probability increases to 97.10%. When the distance to burst center is less than 20 m, the failure probability decreases rapidly, but the decreases reduce while distance exceeds 20 m. Finally, considering the timeliness of blasting vibration, it is found that blasting load makes the failure probability increase 49.61%, and the impact time of single blasting vibration is about 6 seconds.