摘要
借助土性参数,对边坡稳定性分析两大评价体系(安全系数法与可靠指标法)的联系及差异性进行了对比分析.对于简单均质土坡的圆弧形滑裂面,利用积分思想推导了有、无被动土体两种情况下安全系数的精确解析表达式.其中,视被动土体的贡献为减少滑动力矩,采用分段圆弧法推导.以该解析式为基础,利用土体粘聚力与容重的比值将这两个变量归一为变量Hc,以纯黏性土、均质边坡不同坡角时的确定性模型为对象,深入研究了不同的确定性模型情况下,Hc的概率分布类型、均值变化与边坡稳定安全系数的关系及变异特征对边坡失效概率和可靠指标的影响作用等.结果表明:土性参数变异性较强时,安全系数法作为一种定值方法,可能会做出严重背离实际的评判,而可靠指标法则更为科学合理;Hc为正态分布或对数正态分布时,其平均值及变异系数的不同取值会对失效概率(及可靠指标)的计算值以及失效概率(及可靠指标)与安全系数关系曲线中的交汇点位置产生明显的影响.
Based on the shear strength parameters, the relationship and difference between the two assessment methods （the safety factor method and the reliability index method） for slope stability analysis are investigated. A more accurate calculation formula of the safety factor for homogeneous soil slope with and without the resisting part of circle surface failure is established using analytical method. The effect of resisting soil is regarded as reducing of driving moment. The ratio of the coherence to unit w relationships among eigh the t is considered to be the only random variable, labeled by He. The safety factor, the shear strength parameters and failure probability or reliability index are studied in the condition of different distribution and variation mean values or variation coefficients of Ho for different models of purely cohesive slopes. The results reveal that the traditional safety factor method may give unreasonable evaluations, especially for the practical slope project index） with strong variability of parameters~ the calculation value of failure probability （or reliability and the position of the cross point in failure probability-safety factor （or reliability-safety factor） curve are strongly influenced by the mean or variability of He with normal or log-normal distribution.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2008年第6期856-862,共7页
Journal of Dalian University of Technology
关键词
边坡稳定
失效概率
安全系数
可靠指标
slope stability
failure probability
safety factor
reliability index
