Microcrack Evolution and Associated Deformation and Strength Properties of Sandstone Samples Subjected to Various Strain Rates

摘要: The evolution of micro-cracks in rocks under different strain rates is great importance for a better understanding the mechanical properties complex stress states. In present study, series tests were carried out various rates, ranging from creep to intermediate rate tests, so as observe rock and investigate influence on deformation strength rocks. Thin sections samples at pre- post-failure compared analyzed microscale using an optical microscope. results demonstrate that main crack propagation intergranular transgranular higher rate. However, cracks appear mainly around quartz most punctured grains are quartz. Furthermore, exhibit large differences loading directions. addition, uniaxial compressive conducted unbroken tests. A comparison stress–strain curves indicate Young’s modulus peak increase with more energy released by generation than cracks. This study illustrates conspicuous helps understand development microscale, explains relationship between micro- macro-behaviors before collapse rates.