某山坡露天矿边坡稳定性的FLAC^(3D)研究  

Approach to attaining the stability of an open-pit mine by using the fast Lagrangian finite difference method

作　　者：李俊平[1] 王红星[1] 庞静霄 程贤根 

机构地区：[1]西安建筑科技大学材料与矿资学院,西安710055 [2]陕西省地矿局第六地质队,西安710600

出　　处：《安全与环境学报》2017年第2期482-490,共9页Journal of Safety and Environment

基　　金：陕西省科技攻关计划项目(2016YFJH2-10)

摘　　要：某山坡露天矿,原设计的最终边坡角约为46°。为了探索最终边坡角的合理性,应用快速拉格朗日有限差分法FLAC3D在摩尔-库伦准则下搜索该岩质山坡露天边坡的潜在受拉区,判定其稳定性。结果表明:经济合理的最终边坡角是50°38';应用8 m长的锚索加固局部台阶可减小其潜在受拉区中的拉应力;并段将减小边坡的稳定性;爆破开挖时的同段最大装药量与爆距对边坡稳定性影响明显。该方法确定最终边坡角技术可行,它适用于研究岩质边坡的稳定性,克服了用极限平衡法研究边坡稳定性必须事先假定滑动面的弱点。The paper is aimed to make an investigation of the potential tensile zone of the rock open-pit sloping mines and analyze their stability by using the fast Lagrangian finite difference method （FLAC3D） with the Mohr-Coulomb criteria, so as to explore the ultimately rational pit slope angle of such mines, whose original slanting angle of the open pit mine had been designed at an angle of about 46°. To solve the problem, we have, first of all, built up 8 numerical models with 8 different ultimate pit slope angles to compare the actual size of the tensile zone and the value calibration of the tensile stress. The results we have gained from the comparison prove that the economic and rational pit slope angle to be approved should be set at about 50°38＇. And, then, we have managed to build up a corresponding numerical model with the parallel step bench form with the ultimate pit sloping angle being 50°43＇. At the same time, we have also conducted a slope stability simulation test with the static analysis. Taking into account the safety of the slope, we have recommended the slope to be built up without the parallel step form. And, thirdly, we have carried out a static analysis of the safety-involving factors of such rock hillside open-pit slope, believing that it would be possible to reduce the tensile stress in the potential tensile zone if the local step slopes can be reinforced by using an eight meters＇ long anchor cable under the condition that the safety factor should be made to reach 1.3. Last of all, we have also done a dynamic analysis for the slope blasting extraction by applying the calibrated blast pres- sure to the extraction face in the form of pressure generated by the ANSYS/LS - DYNA. The results of the analysis demonstrate that the maximum charge of the same millisecond blasting section for the excavation and the blasting distance should he taken as the two main factors that may affect the stability of the slope. Thus, the method we have developed in this paper for testing the stability of the

关 键 词：安全工程 露天开采 边坡稳定性 最终边坡角 快速拉格朗日有限差分法 锚索加固 

分 类 号：K936[历史地理—人文地理学]