关键词: 洛河组砂岩, 冻融过程, 力学性质, 破坏特征

Abstract: In this paper, a complete freeze-thaw process of Luohe formation sandstone is carried out by reducing the freezing process in the West and changing the freezing temperature. The quality and wave velocity of Luohe formation sandstone before and after thawing were measured. Based on the mechanical test, the influence of mechanical properties and confining pressure on mechanical parameters and failure characteristics of Luohe formation sandstone were obtained. The test results show that the Luohe formation sandstone has large porosity, strong water absorption capacity and good water saturation. After thawing, the mass loss rate is 5% and the wave velocity loss rate is 40%. That is to say, the Luohe formation sandstone is very sensitive to freeze-thaw action. With the decrease of freezing temperature, the frost heaving force inside the sandstone increases, and the damage intensifies. After thawing, the strength and deformation of Luohe formation sandstone are deteriorating and the deformation is increasing From the original single failure mode to the tension shear composite failure mode, the main crack becomes wider, accompanied by many secondary cracks.