地下水位随机性影响下的边坡可靠性分析  

Reliability Analysis of A Slope Considering the Randomness of Groundwater Table

作　　者：何朋朋[1] 姚磊华[1] 刘立鹏[1] 陈庆[1] 

机构地区：[1]中国地质大学工程技术学院,北京100083

出　　处：《吉林大学学报（地球科学版）》2009年第2期288-293,共6页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40372110)

摘　　要：在边坡稳定性评价模型中可将地下水的水压力总分为静水压力和动水压力。建立考虑水压力的剩余推力法边坡稳定性力学分析模型。推导了利用已知两点地下水位求解其间任一点地下水位和含水层厚度的求解公式。将地下水位和滑面的抗剪强度指标作为随机变量，利用已有数据求其分布特征，提出基于Monte-Carlo法与剩余推力法的边坡可靠性分析方法，并对某公路边坡进行可靠性分析。计算结果表明地下水位的变化与边坡失效概率的变化成正相关关系。在地下水位变化较大的7、8、9月，将地下水位作为随机变量计算得到的边坡失效概率为60％左右，而将地下水位作为确定量计算的边坡失效概率为10％～30%；在地下水位变化不大的其它月份，二者差别不大，但前者总大于后者。Water pressure of groundwater can be separated into hydrostatic pressure and hydrodynamic pressure in evaluation model of slope stability and the mechanical analytic model of slope stability is developed by using residual thrust method when considering water pressure of groundwater. Formulas are also induced to calculate the thickness of aquifer and water head in any point between the two points in which groundwater table is given. Taking groundwater table and shear strength index as stochastic variables and the distribution features of these two variables can be obtained basd on the monitored and tested data, the analytical method of slope reliability based on Monte- Carlo method and residual thrust method has been put forward to analyze the slope reliability of a highway slope. Analytical results show that there is a positive correlation between the change of groundwater table and the change of failure probability of slope. Failure probability of slope is approximately 60% when taking groundwater table as stochastic variable, but is 10%- 30% when taking groundwater table as determinable variable during the periods of July, August and September when groundwater table changes dramatically. In other months, groundwater table varies slightly and failure probability of slope also varies slightly, but the failure probability of slope when taking groundwater table as stochastic variable is always higher than that when taking groundwater table as determined variable.

关 键 词：边坡可靠性 随机性 地下水位 剩余推力法 安全系数 地下水 

分 类 号：P642.2[天文地球—工程地质学]