循环加载高压流变实验中塑性应变分析

在三轴应力下的流变实验中，通过循环加载方法测出轴向应变，轴向塑性应变和弹性模量随差应力的变化，再根据多孔介质有效弹模理论，计算出岩石变形中孔隙度的变化，在假定岩石骨架不可压缩下，得到体积膨胀应变，然后通过总塑性应变与扩容机制和位错机制应变的关系，分解出位错应变，结果表明：在低围压下（＜100MPa），扩容应变占优势，并伴随着部分位错应变，在高围压下（＞100MPa），位错应变占优势，只有较小的扩容应变。

Analysis of Plastic Strain in Rhology Experiment with Cycle Loading

In rhology experiment under traxial stresses, cycle loading method is used to measure axial strain, axial plastic and elastic modulous change with difference stress. Based on the theory of effective elastic modulous, porosity during deformation of rock is calculated. Under the hypothesis that structure of rock is incompressive, dilatancy strain is obtained. According to relation among total plastic strain, dilatancy strain and dislocation strain, the dislocation strain is seperated. The results show that under low confining pressure (<100MPa), the dilatancy strain occupies advantage with partial dislocation strain; under high confining pressure(>100MPa), dislocation strain occupies advantage with little dilatancy strain.