以实测的围岩蠕变变形资料为基础,基于现场监测所获得的蠕变本构模型,对某一矿区泥岩体的力学参数进行了弹塑性反演分析,得到的巷道围岩体基本力学参数分别为弹性模量E=2.0 GPa,凝聚力c=1.31 MPa,内摩擦角?=24o。待反演参数水平均值的极差结果显示,通过极差的大小可以判断岩土力学参数的敏感性,对蠕变的影响而言,凝聚力最敏感,其次是内摩擦角,弹性模量再次之。在此基础上,利用反演所得的围岩基本力学参数进行了正演,计算得到了各测点处对应的蠕变位移增量,与实测值相比吻合较好,表明反分析所获得的岩体材料参数综合反映了巷道围岩的力学特性。最后,对巷道围岩变形大小及塑性区范围进行了预测。
Based on the observed data of the creep deformation of surrounding rock and creep constitutive model for weak rock mass, back analysis of elastoplastic parameters of surrounding rock for roadway in mudstone is done. The rock mechanical parameters are obtained by back analysis;the obtained elastic modulus is 2.0 GPa;cohesive force is 1.31 MPa and angle of internal friction is 24o. The range analysis results for the mean values of inversion parameters show that the size of the range can be used to judge the sensitivity of rock mechanical parameters. For the creep character, cohesive force is the first influence factor;the second one is the angle of internal friction and the third one is the elastic modulus. Then, deformation of the surrounding rock is calculated using the basic mechanical parameters obtained by back analysis;the creep displacement increment in each observed point is calculated;and they are in good agreement with the measured values. These results show that the actual situation of roadway is reflected by the deduced rock mechanical parameters. Finally, the displacements and plastic zone range of roadway are predicted.