岩土工程学报Issue(6)：1095-1105,11.DOI:10.11779/CJGE201406015
考虑不排水抗剪强度空间变异性的条形基础极限承载力随机分析
Stochastic analysis of ultimate bearing capacity of strip footing considering spatial variability of undrained shear strength
摘要
Abstract
The effect of the variation of shear strength parameters of soils with depth on the stability of footing has not been thoroughly studied. A stochastic method is proposed for bearing capacity analysis of strip footing considering the variation of the mean and standard deviation of undrained shear strength parameters with depth. A non-stationary random field model is established, and the random field is discretized by the Karhunen-Loeve (KL) expansion. The effect of spatial variability of the undrained shear strength parameters on the ultimate bearing capacity is investigated. The results of bearing capacity associated with stationary and non-stationary random field models are compared. An undrained clay foundation is presented to demonstrate the effectiveness of the proposed method. The results indicate that both the mean and standard deviation of bearing capacity increase with the increasing correlation length, and that the ultimate bearing capacity is more sensitive to the vertical correlation length than to the horizontal one. The mean of the ultimate bearing capacity decreases but the standard deviation increases as the coefficient of variance increases. The spatial variability of shear strength parameters of soils has a significant influence on the failure probability of foundation. When the factor of safety is large, the failure probability of foundation decreases with the decreasing correlation lengths. Compared with the non-stationary random field, stationary random field will highly overestimate the variation of the ultimate bearing capacity. When the factor of safety against shear failure is low, the stationary random field model will induce a lower probability of failure than the non-stationary random field model. On the contrary, when the factor of safety against shear failure is high, the stationary random field model will induce a higher probability of failure.关键词
地基稳定性/不排水抗剪强度/空间变异性/随机场/KL展开/极限承载力Key words
foundation stability/undrained shear strength/spatial variability/random field/Karhunen-Loeve expansion/ultimate bearing capacity分类
建筑与水利引用本文复制引用
祁小辉,李典庆,周创兵,方国光..考虑不排水抗剪强度空间变异性的条形基础极限承载力随机分析[J].岩土工程学报,2014,(6):1095-1105,11.基金项目
国家杰出青年科学基金项目（51225903）；国家重点基础研究发展计划（973计划）项目（2011CB013506）；国家自然科学基金项目 （）
