摘要
目前有关抗剪强度参数随深度变化的随机场对深基础地基稳定性的影响研究还不深入。为此,建立了土体不排水抗剪强度均值和标准差随深度有不同程度线性增加的非平稳随机场模型,此外,还建立了与非平稳随机场对应的不排水抗剪强度均值与其相同的平稳随机场模型。探讨了不同非平稳程度的随机场对深基础地基承载力及其失效概率的影响规律,比较了各个非平稳随机场地基模型与其对应的平稳随机场地基模型的地基承载力的差异性。结果表明:当考虑不排水抗剪强度的非平稳性时,地基承载力均值和差异性随非平稳程度的提高而线性增加。基础埋深越大,地基承载力均值随非平稳程度提高而增加的趋势也越大。在相同的安全系数水平下(FS>1),地基失效概率随着非平稳程度的提高而增大。对深基础而言,在相同的安全水平下(FS>1),平稳随机模型会低估具有非平稳性的地基的失效概率,且非平稳程度越高,估计误差也越大。
The impact of the variation of shear strength parameters of soil with depth on the stability of buried foundations has not been thoroughly studied yet.A non-stationary random field model in which the mean and standard deviation of undrained shear strength of soil increase linearly with depth with different degrees was established.In addition,the stationary random field with the same mean of undrained shear strength as the corresponding non-stationary random field was established.The influence of non-stationary random fields with different degrees on the bearing capacity of buried foundations and the failure probability of buried foundations were discussed.The difference of bearing capacity associated with non-stationary random field and its corresponding stationary random field was compared.The results show that when considering the non-stationary of undrained shear strength,the mean value and the difference of bearing capacity of buried footings increase linearly with the degree of non-stationary.The deeper the foundation depth is buried,the more the average bearing capacity increases with the increase of non-stationary degree.Under the same safety factor level(FS>1),the failure probability of the foundation increases with the increase of non-stationary degree.For the buried foundation,at the same level of safety(FS>1),the stationary stochastic field model underestimates the failure probability of a non-stationary field,and the higher the non-stationary state,the larger the estimation error.
作者
周旭辉
李睿
吴勇信
ZHOU Xuhui;LI Rui;WU Yongxin(College of Civil and Transportation Engineering,Hohai University,Nanjing,Jiangsu 210024,China;PowerChina Huadong Engineering Corporation Limited,Hangzhou,Zhejiang 311122,China)
出处
《河北工程大学学报（自然科学版）》
CAS
2020年第2期30-37,共8页
Journal of Hebei University of Engineering:Natural Science Edition
基金
国家自然科学基金重点项目(41630638)。
关键词
地基稳定性
非平稳性
随机场
不排水抗剪强度
地基失效概率
foundation stability
non-stationary
random field
undrained shear strength
failure probability
作者简介
周旭辉(1994-),女,江苏南京人,硕士,主要从事岩土工程可靠度与风险分析的研究;通讯作者:吴勇信(1985-),男,江苏射阳人,博士,教授,主要从事岩土地震工程与工程可靠度领域的研究。
