基坑变形及其安全性的随机预测

将基坑支护与周围土体视作一个不确定性系统，在对随机性很强的现场位移量实测数据建立提取趋势项和分离随机项方法的基础上，采用蒙特卡罗法建立了确定土性参数的随机反分析方法，由此得到可反映土体整体力学性质的不确定性参数。还据以建立了基坑变形的预测计算模型，包括预测基坑未来变形量的概率分布，及对基坑工程的安全性作概率意义上的判断。分析过程中，对土的流变性特征采用粘弹性本构模型进行了工程简化。提供的工程应用实例表明了此方法的可靠性。

Stochastic Prediction of Deformation and Security of Foundation Pit

The support of foundation pit and the surrounding soil are considered as a large uncertain system,the displacements of them measured in situ are separated into deterministic trend and stochastic part.Then by employing the Monte Carlo Technique,a stochastic back analysis method has been established to determine the soil parameters,which can describe the behavior of soil mass and reflect its macrocosmic uncertain mechanical property.Based on the determination of parameters,a calculation model of deformation prediction has been put forward,which can be used to obtain the deformation in future,including the probability distribution of them and the probabilistic safety forecast of foundation pit.During the process of analysis,in order to take the rheological property of soil into account and simplify the calculation process,the Kelvin-Voight constitutive model is employed.A case study is given out at the end to show that the method of the paper is credible.