摘要
以延安市宝塔区虎头峁黄土斜坡为研究对象,在野外详细调查和勘查的基础上,分析确定斜坡可靠度的随机变量为滑带土土体容重r、内聚力c和内摩擦角φ。分别用统计矩法、一次二阶矩法、几何法和蒙特卡洛模拟法计算斜坡的可靠度和破坏概率,得出安全系数为1.00-1.15,可靠度指标为0.35-0.45,破坏概率为32%-37%,说明斜坡具有较大的失稳可能性。计算过程表明,用几何法计算所得的可靠度指标精度最高,一次二阶矩法次之,统计矩法计算精度最低,蒙特卡洛模拟法可作为一种校验方法,对其他方法进行校验和对比。在不需要获取传统的定值安全系数的情况下,可用几何法计算斜坡的可靠度指标,方法较为简便。当需要同时获取安全系数时,应使用统计矩法或一次二阶矩法计算。
This article takes the Hutoumao loess slope in Yan＇an City as the research objective. The soil density r, cohesion c and frication angle ψ of the soils of the slip zone were analyzed and determined as the random variables of the slope reliability on the basis of detailed field survey and exploration. Using the moment estimation method, first-order second-moment method, geometry method and Monte-Carlo simulation method, the slope reliability index and destruction probability were calculated separately. The safety factor is 1.00-1.15, reliability index is 0.35-0.45 and destruction probability is 32-37%. The results show that the slope is more likely to be unstable. The calculation process indicates that： the geometry method has the best reliability index precision, the first-order second-moment method is less precise, and the moment estimation method is least precise. The Monte-Carlo simulation method can check the results of others methods as a verifying method. The geometry method can be used when the fixed safety factor is not necessary, because it is relatively easy. But when there is a need to know the safety factor, the moment estimation method and the firstorder second-moment method are in point.
出处
《地质通报》
CAS
CSCD
北大核心
2008年第8期1217-1222,共6页
Geological Bulletin of China
基金
"十一五"国家科技支撑计划重点项目<重大地质灾害监测预警及应急救灾关键技术研究>(编号:2006BAC04B00)
中国地质调查局<延安宝塔区地质灾害监测预警示范>(编号:1212010740907)
<陕西省延安市宝塔区地质灾害详细调查与风险管理示范>(编号:1212010640326)资助。
关键词
可靠度
黄土斜坡
稳定性
随机分析
reliability index
loess slope
stability
stochastic analysis
