在围压条件下岩体模型应力应变关系的实验研究

含切口岩体模型在差应力作用下的应力应变关系表明:岩体不同部位的应力应变曲线按斜率变化特征可以划分为四个发展阶段。根据对切口岩石破裂过程的对比,各阶段的变形机制分别与岩体内原微裂纹闭合、孔隙和颗粒弹性变形、宏观张裂剪裂以及剪切、张-剪主破裂相对应,但各阶段的发展进程在时间、空间上却不一致,这一差异均与切口分布和岩性变化相关。最后讨论了应力应变特征与发震断层孕震过程的关系,对地震预报可能有实际意义

EXPERIMENTLAL STUDIES ON THE RELATIONSHIP BETWEEN STRESS AND STRAIN OF ROCK MASS MODELS UNDER CONFINING PRESSURE

The characteristics of three typical models of rockmass have been studied under room temperature and confining pressure. The results suggest that the stress-strain curves can be divided, into four stages by the behaviours of linear and nonlinear elasticity. The deformation mechanisms are correspondent to the closing of preexisting cracks, elastic deformatiom of grains and pores, macroscope tension (tensile region), shear (compressive region) and main shearing or shearing-tension ruptures, respectively. The resulting processes of these curves stages in longitudinal and transverse direction near the tip of saw-cut and in the region of homogeneous stress state were different in time. The fracture propogation related to the change of stress-strain stage was not considered in time and space.The characteristics of stress-strain curves and distributions and sequences of fracture propagation were controlled by structure features of models of sawcut rockmass.Finally the relationship between the developing stages of stress-strain in some points along the seismogenic fault and the preparation of earthquakes, has been discussed