兰桥排土场边坡失稳模式及其稳定性数值分析  

Numerical Analysis of Instability Mode and Stability for Lanqiao Dump Slope

作　　者：许旭堂[1,2] 简文彬[1,2] 

机构地区：[1]福州大学岩土工程与工程地质研究所 [2]福州大学资源与城乡建设系,福州350108

出　　处：《防灾减灾工程学报》2013年第6期686-690,共5页Journal of Disaster Prevention and Mitigation Engineering

摘　　要：以兰桥矿区排土场边坡工程为例,在掌握排土场边坡工程地质条件的基础上,详细分析该多台阶排土场边坡失稳的破坏模式和主要影响因素,采用极限平衡法和有限元强度折减法对其稳定性进行分析。计算结果表明,该边坡可能沿着排土场下卧腐殖土层滑动,塑性区首先在腐殖土层贯通,接着主要向上产生2条塑性区变化带,其中沿着中部台阶边坡发展的塑性区较早贯通,而塑性区朝坡顶的贯通相对滞后;随着地下水位的升高,竖向拉应力区有扩展趋势,其产生的附加位移越大,对边坡的安全越不利;以竖向增量位移的变化趋势作为监测和分析边坡稳定性的依据时,应避开位移为零或变化很小的坡段;水平增量位移集中于坡脚,并且在边坡中部偏下的位置开始产生剧变,这种不连续的过渡,更加剧了边坡失稳的可能性。Based on the dump slope engineering geotechnical conditions, analyses of the instability mode and main impact factors of dump slope with multi-step in details were taken, and stability conditions were simulated by the limit equilibrium method and the finite element strength reduc- tion method. The results show that the slope may slide along the humus layer, and the plastic zone passes through the humus layer firstly, then produces two upward plastic changing belts. The plastic zone along the central bench-shape slope develops earlier while the other one which passes through the top of the slope lags relatively. The more ground water level rises, the larger additional displacement of the slope will be, then the vertical tensile stress zone has the trend of extending which make the slope more unsafe. The slope sections where displacement is zero or changes little should be avoided when monitor and analysis of slope stability is based on the the vertical incremental displacement trend. The level incremental displacement is focused on the bottom of the slope, and the upheaval is produced on the position of the lower middle of slope, fi- nally this kind of discontinuous transition increases the possibility of slope instability.

关 键 词：排土场边坡 塑性区 增量位移 边坡稳定性 

分 类 号：P642.2[天文地球—工程地质学]