Tests for Sandstone Strength and Failure Model Under Water Loading

The conventional uniaxial experiment and the compression tests under different water pressure were carried out by using MTS and YSL-200 test system.The effect of the water pressure on compression strength and failure model of saturated sandstone was analyzed,and the acting of pore water pressure and confining pressure on rock strength was discussed.The results showed that the saturated sandstone was X-type shear failure under water pressure,and water pressure accelerated the failure of rock obviously while the rock was in crack propagation area.The pressure water could seep into rock interior through propagated cracks so that the moisture content of rocks was increased and the pore water pressure of rock interior was affected.When water pressure was low,the confining pressure was greater than the pore water pressure,and the rock strength was enhanced by water pressure; but when water pressure was relatively high,the pore water pressure had risen to offset the increased confining pressure,and the rock strength under water pressure was similar to uniaxial compressive strength.