侧向约束条件下砂岩的压缩蠕变特性研究

近年来,岩石蠕变而引起的隧道工程及大型地下硐室的长期稳定性问题受到国内外学者的广泛关注,蠕变试验的研究也取得了极大的进展。模拟巷道围岩的受力状态,通过试验研究了砂岩在单轴压缩及侧向约束条件下的蠕变特性,对比分析了2种试验条件下的蠕变变形规律:侧向约束下将发生加速蠕变的应力阀值和极限应变有较大提高,蠕变速率得到减缓。在试验数据的基础上,分析了岩石粘弹性变形随应力水平不同和时间发展的变化规律,为数值分析和理论计算提供了试验依据。

Study on Sandstone's Compression Creep under Lateral Restriction

In recent years, the long-term stability problem of tunnel and large underground cavern caused by rock creep has been widespread focused by scholars at home and abroad. And great progress on the experimental research of rock creep has been made. Through the simulation of the stress state of surrounding rock, the Sandstone's uniaxial compressing creep tests under un-lateral restriction and lateral restrain were made respectively, and their creep deformation rules were comparatively analyzed. The test results show that the stress threshold value and ultimate strain value of accelerative creep were increased, and the creep rate was reduced. Based on the experimental data, the viscoelastic deformation rules with the rock stress level and time variation was proposed, thus providing the experimental basis for the numerical simulation and theoretical calculation. 