基于模式搜索的岩石流变模型参数识别

RHEOLOGICAL MODELAND PARAMETERS IDENTIFICATION OF ROCK BASED ON PATTERN SEARCH AND LEAST-SQUARE TECHNIQUES

介绍一种根据岩石蠕变试验资料识别流变模型参数的方法,该方法是模式搜索与非线性最小二乘法的有机结合,避免了曲线拟合中由于流变参数初值选取不当、迭代不收敛的困难。用该方法对某工程粘土岩室内单轴压缩蠕变试验进行了研究,识别出了不同应力水平下的流变力学参数。研究表明,采用伯格斯模型描述该类粘土岩的流变力学特征比广义开尔文模型更为合适。

An identification method of rheological model and associated parameters of rock based on laboratory creep experiments are presented. The method is established by using a mixed technique of pattern search and non-linear least-square regression,which can avoid regression divergence when initial rheological parameters are not optimally selected. The method is applied to investigate creeping tests of clay stone samples under uniaxial compression from an engineering projects,and the relevant rheoligical parameters of the samples using Burgers model are achieved. The results show that this model is preferable to the generalized Kelvin’s model.