岩石统计损伤软化模型及其参数反演

为了反映岩石应变软化现象,基于岩石微元强度服从Weibull随机分布的假定,结合连续损伤理论,建立岩石统计损伤软化模型。该模型含有2个待定系数,其中一个可通过岩石应力-应变曲线的峰值点确定,另一个取决于微元强度参数。通过研究微元强度参数对所建模型的影响,采用优化反演分析法确定模型参数,克服传统方法求解模型参数精度较低的难点,并依据微元强度参数选取合理的强度准则。采用YSJ-01-00岩石三轴流变试验机进行红层泥岩常规三轴压缩试验,对比试验曲线和理论曲线,验证了本文模型和方法的正确性与合理性。

Statistical Damage Softening Model for Rock and Back Analysis of Its Parameters

On the premise of assuming that micro-unit strength obeys Weibull distribution,a statistical damage sof-tening model for rock is established based on the continuum damage theories to reflect the strain softening of rock. The model contains two undetermined coefficients,one of which can be determined by the peaks of stress-strain curves,and another depends on the micro-unit strength parameters.By analyzing the influence of the micro-unit strength parameters on the model,the model parameters are determined through optimized back analysis.On this basis,reasonable strength criterion is selected according to the micro-unit strength parameters;hence the low preci-sion of solving model parameters by traditional methods are overcome.Furthermore,the correctness and rationality of the proposed method are verified by conventional triaxial compressive test of red-bed mudstone on YSJ-01-00 rock triaxial creep testing machine.