软黏土蠕变模型参数的确定方法研究

Determination of the parameters of visco-elastic-plasticity model for creep of soft clay

土的蠕变问题进行数值分析一般都需要用黏弹塑性有限元的方法来求解,如何取参数是关键性的问题。软黏土的蠕变过程可能持续几十年甚至上百年的时间,而实验室中的实验一般只进行几个小时或者几天最多几个月的时间,因次,用短时间的实验数据来外推长时间范围的结果就显得非常重要。提出了利用实验数据估算软黏土蠕变模型有限元参数的方法,并利用黏弹塑性有限元程序计算天津港突堤蠕变问题的计算结果来分析模型参数的变动对蠕变问题的计算结果的影响。采用了所提出的参数分析和评价方法的黏弹塑性有限元系统被运用于多项工程计算中,取得了良好的效果。

The visco-elastic-plasticity model is often used to solve soil creep problems. The key point is how to determine the parameters for the complex model. These parameters have to be obtained with the laboratory tests. However,the soil creep process may last for several decades or even hundreds of years,while the laboratory tests can not be carried out for more than several months at most. Therefore,it is very important to estimate the reasonable parameters for FE analysis by extrapolating the laboratory test results. In this paper,a statistical method is presented to give an estimation of the parameters for the visco-elastic-plasticity mode. The estimated parameters have been successfully used to assess the creep tendency of Tianjin Harbor and several other projects in which the creep effect is concerned.