竖井地基固结概率分析的点估计法

Probability analysis of consolidation of ground with vertical drain using point-estimate method

将竖井地基固结度表达式直接作为功能函数,采用点估计法计算固结度的均值、标准差等各阶统计矩,由各阶统计矩可方便计算出竖井地基达到某一固结度的概率。与传统概率分析方法相比,如一次二阶矩法,点估计方法无须事先引入控制指标来建立极限状态方程,计算过程更为简便。实例分析表明,当估计点较多时(如5点),点估计方法具有较高的计算精度,与Monte Carlo法相当,是一种简便而不失精度的概率分析方法,适合工程实际应用。

Taking the degree of expression for consolidation of ground with vertical drain as the function of probability analysis, the point-estimate method （PEM） was developed to compute the statistical moments of degree of consolidation, such as the mean and standard variance, and the probability ground degree of consolidation of wits vertical drain was calculated from these statistical moments. Compared with the traditional probability analysis methods, such as the first order second moment method, the PEM was simple and was not necessary to introduce control index to establish the limited-state-equation, and the computational process was convenient. When there were many estimated points （for instance, five points）, in a case study, it was indicated that the PEM was as precise as Monte Carlo method, so it was a simple, convenient and precision-insured method, and it could be used in practice.