基于UDEC的岩质边坡开挖爆破节点拟静力稳定性计算方法

NODE QUASI-STATIC STABILITY ANALYSIS OF ROCK SLOPE UNDER EXCAVATION BLASTING BASED ON UDEC

提出一种计算岩质边坡爆破开挖情况下边坡安全系数的节点拟静力法。通过节点拟静力法可确定爆破荷载作用下边坡潜在滑动面的位置、破坏模式以及安全系数。节点拟静力法的基本思路包括3个部分:首先,基于二维离散元计算软件UDEC4.0内嵌的程序语言FISH,对UDEC4.0进行二次开发,编写考虑爆破振动峰值加速度随爆心距和高差衰减规律的计算程序;其次,基于强度折减法的基本原理,编写强度折减计算程序;最后,坡体临界状态判别方法的选择,提出用最大节点位移历时曲线来判断坡体的临界状态的新的边坡失稳判据。同时与UDEC自带程序的计算结果相比较,证明节点拟静力法的正确性和可行性,最后把节点拟静力法应用于云浮硫铁矿露天采场边坡的爆破设计和稳定性评价。

A node quasi-static method to calculate the safety factor of rock slopes under blasting case is given. Potential sliding surface slope position,failure mode and safety factor of slopes undertaking the blasting loads can be obtained by the node quasi-static method. The node quasi-static method consists of three parts. Firstly,secondary development on UDEC4.0 is conducted based on the FISH language embedded in UDEC4.0,and the calculation program considering the attenuation law of blasting vibration peak acceleration with blast center distance and elevation difference is written. Secondly,strength reduction calculation program is written based on the basic principles of strength reduction. Finally,choosing the discrimination method for slope critical state,and a new slope failure criterion that utilizes the maximum node displacement duration curve to determine the slope critical state is proposed in this paper. Through comparing with the calculation results obtained by UDEC system procedure,the correctness and feasibility of the node quasi-static method is verified. Finally,the node quasi-static method is applied to the blasting design and stability evaluation of Yunfu pyrite open-pit slope.