岩石损伤本构模型在大理岩三轴卸荷试验中的应用

依据岩石强度服从统计分布的特点，通过定义损伤变量，并在一定的假定条件下，运用岩石力学中的D-P强度准则，建立岩石损伤本构模型。对大理岩在不同卸荷速率条件下的试验结果进行分析，利用试验所得的岩石力学参数及求解数据，通过拟合求得损伤本构模型的分布参数，进而确定损伤本构模型的演化曲线。通过与试验曲线对比分析，结果表明:理论曲线基本能反映大理岩在三轴卸荷条件下的应力-应变关系及强度特点；导致高卸荷速率下的大理岩试件强度相对要低的原因，是高卸荷速率的岩石在卸荷过程中其内部损伤演化发展相对要快。

Application of Rock Damage Constitutive Model in Triaxial Unloading Test of Marble

Based on the rock strength statistical distribution, defining damage variable, in certain assumed condition, the D-P strength principle in rock mechanics was adopted to build rock damage constitutive model. Test results of marble in different unloading speeds were analyzed. Rock mechanical parameters obtained from the test were used to solve the data, and through fitting, the distribution parameters of damage constitutive model were obtained and the evolution curve of damage constitutive model was confirmed. Through comparison with the test curve, the results show that the theoretical curve of marble can reflect the stress-strain relationship and strength characteristics under the condition of triaxial unloading. At the same time, confirm that the reason why low strength marble sample gets faster unloading rate is that, in the unloading process, the high unloading rate rocks’ development of internal damage evolution is relatively faster.