ZHANG Qiang, LI Xiao-chun, ZHOU Ying-bo, et al. Shear behavior of the Triassic sandstone in Sichuan
under high pore pressure of H2O/CO2 conditions[J]. 2019, 40(8): 3028-3036.
ZHANG Qiang, LI Xiao-chun, ZHOU Ying-bo, et al. Shear behavior of the Triassic sandstone in Sichuan
under high pore pressure of H2O/CO2 conditions[J]. 2019, 40(8): 3028-3036.DOI: 10.16285/j.rsm.2018.2273.
Understanding shear behavior of a sandstone is vital for underground engineering projects
such as mining
underwater tunnel excavation and CO2 geological storage
and so on. In this study
the shear behavior of a intact sandstone under dry/saturated/H2O-injected/CO2-injected conditions were conducted using a shear-flow test apparatus. The results show that the shear strength and the residual shear strength were increase with the effective normal stress under dry/saturated/H2O-injected/CO2-injected conditions. The shear stiffness was also increase with the normal stress under dry condition. The effect of pore pressure on the shear strength follows the Terzaghi effective stress law. Water/CO2 could weaken the shear strength. Water lowered the internal friction angle φ
CO2 hardly affected it. CO2 lowers the cohesion stronger than that of water. The reasons of the weakening effect of water and CO2 were the interaction of fluid-rock
and the weakening effect of water on the clay contained in the sandstone was stronger than that of CO2.