Abstract:Using full stress and multi-field coupling triaxial apparatus, the hydro-mechanical coupling triaxial compression drainage tests were carried out on saturated granite with different loading rates, confining pressures and pore pressures. The stress-strain curves of saturated granite under different loading rates and effective confining pressures were provided respectively, and the variation rules of peak strength, peak strain and elastic modulus were studied under the very loading rates and effective confining pressures. The results show that:(1)under the effect of different effective confining pressures and loading rates, stress-strain curves of saturated granite exhibit the nonlinear compaction, elasticity, yield and failure stages. At the initial stage of deviating stresses loading, the nonlinear compaction stage is relatively obvious, but with the increase of confining pressure, the nonlinear compaction stage gradually disappears. Due to the high density of granite, the linear elastic stage of the curve is long and relatively smooth. In the yield and failure stages, the rock shows obvious brittle-ductile transformation process.(2)The peak strength of saturated granite increases with the increase of loading rate, and when the effective confining pressure is constant, the peak strength is approximately equal, and the resistance to external load is roughly the same.(3)Under the condition of slow loading, the loading rate has obvious strengthening effect on the peak strain of saturated granite, while the strengthening effect is limited. When the effective confining pressure is constant, with the synchronous increase of confining pressure and pore pressure, the peak strain presents an increasing trend.(4)Elastic modulus and loading rate show a quadratic polynomial growth relationship. However, with the synchronous increase of confining pressure and pore pressure, the elastic modulus presents a decreasing trend.