针对锦屏二级水电站深埋长大隧洞(埋深2 525 m,长19 km,宽13 m)围岩在开挖与运营过程中呈现出显著的流变劣化特征,采用CSS–283双向万能实验机,对含硬性结构面的大理岩进行剪切流变特性的实验研究,分析岩石黏弹变形随应力水平不同和时间发展的变化规律;在对实验数据和定常流变模型本构关系深入分析的基础上,引入与时间有关的非确定参数,提出一种非定常流变模型,并建立其在一维情况下蠕变方程;通过对定常流变模型理论、非定常流变模型理论和流变实验结果的比较表明,考虑参数时间相关性的非定常黏弹流变模型比定常黏弹流变模型更为准确地反映了岩石的黏弹性变形性能。研究结果是对岩石非定常流变模型研究的一种初探,并对锦屏二级水电站深埋长大隧洞工程有重大的参考价值。
To the marked rheological and deteriorated characters appearing in process of the wall rock excavation and operation of the Jinping Hydropower Station long,large and deep-buried tunnel with depth of 2 525 ml,ength of 19 km,width of 13 m,the experimental investigation on the shear rheological character of marble with hard structural surface is done by using the CSS–283 two-way universal testing machine,the relationship among stress level time and viscoelastic deformation disciplines of rock is analyzed.Based on the profoundly research to the test data and the constitutive equations of stationary rheological model,the non-stationary parameters are achieved,and the non-stationary rheological model and a one-dimensional creep equation is established.By the comparison with the theoritical results of the stationary and non-stationary rheological models and the test results,the results indicate that the non-stationary viscoelastic Maxwell rheological model,considering time-dependent behaviors of the parameters,is the more exactly reflect the rock viscoelastic deforming performance than the stationary viscoelastic rheological models.The research result is a preliminary exploration on the research of the rock non-stationary rheological model,and it offers reference value to the research of the long,large and deep-buried tunnel of the Jinping Hydropower Station.