Abstract:Rock specimens of red sandstone rocks taken from Longyou Grottoes in China¢s Zhejiang Province are obtained that contain one or two preexisting flaws. Erosive effects of water chemistry of cracked rocks are studied under different chemical solutions and the same velocity. Variations of the mass and wave velocity of the specimens and pH values of solutions with sandstone being soaked are obtained;and the erosion characteristics are analyzed. Based on the results of uniaxial compressive test under different chemical solutions and velocities,the effects of strength and deformation and main modes of crack coalescence are analyzed according to uniaxial compressive stress-strain curves for different cracked rocks under chemical corrosion. The studies indicate that the specimen quality variations have not relations with chemical solutions. The pH value in the chemical solutions ultimately tends to neutral pH,and the elastic wave velocity ultimately almost does not change with time. Preexisting crack arrangement,the pH value and velocity of the chemical solutions all have great influences on the sandstone samples¢ uniaxial compressive strength. Cracked red sandstone sample are tension destruction under uniaxial compression;and the crack propagation direction are consistent with the loading direction. The modes of crack coalescence for specimens containing 1- or 2-flaw are tension and tension-shear modes. Immersion velocity and the chemical solution have not influence on the modes of crack coalescence. The research result provides understanding of the fundamental nature of rock failure and damage mechanics models for simulating nonlinear evolution of tested rock under coupled mechano-hydro-chemical processes.