岩石在高水压条件下的强度和变形破坏方式对深埋、高水压下隧洞及地下开采极为重要。采用MTS和“YSL-200”对砂岩进行了常规单轴试验和不同压力水环境中的压缩试验，分析了真实水压力对饱和砂岩的抗压强度和破坏形式的影响，并探讨了孔隙水压力与水围压力对岩石强度的作用。试验结果表明：饱和砂岩在真实水压力环境中呈现“X型”剪切破坏，水压力在岩石进入裂纹扩展区时加速岩石破坏的作用效果明显；压力水可以通过扩展的裂纹渗入到岩石内部，增大岩石的含水率，影响岩石内部的孔隙水压力；当水压力较低时，水围压作用大于孔隙水压力作用，水压力对岩石的强度为增强效应，当水压力较高时，孔隙水压力作用与水围压作用抵消，岩石强度与饱和单轴抗压强度相近

Accroding to the features of water directly against the rock surface, the conventional uniaxial experiment and the compression tests under different water pressure was carried out. The effect of the water pressure on compression strength and failure model of saturated sandstone was analysed, 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, 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.