关键词: 砂岩, 蠕变特性, 饱水, 蠕变速率, 长期强度, 三轴压缩蠕变试验

Abstract: The roof of roadway in mine has strong creep characteristics under the action of water, posing great threat to mine excavation and production. In this research we investigated the creep mechanical behavior of sandstone in different water-bearing conditions through triaxial rheological compression test. Test results showed that: (1) with the increase of water-saturation time and the climbing of stress level, instantaneous strain and creep both increased. (2) With the enhancement of water-bearing state, the initial creep rate and steady-state creep rate gradually increased, and the steady-state creep rate was in a power function relationship with the stress level.(3) By comparing two different long-term strength methods, we found that the long-term strength of sandstone under conditions of natural state, water-saturated for 1 day, and water-saturated for 5 days was only 64.12%, 62.08% and 59.34% of its instantaneous strength, respectively,and the long-term strength attenuation aggravated under the action of water.

Key words: sandstone, creep behavior, water-saturated, creep rate, long-term strength, triaxial compressive creep test