岩石的非定常Burgers模型

Non-stationary Burgers model for rock

建立一个与时间、应力状态有关的非线性黏滞体,该黏滞体可以描述岩石的非线性黏弹性流变特征;将该非线性黏滞体替换Burgers模型中的线性黏滞体,得到修正Burgers模型,该模型也称为非定常Burgers模型。对锦屏二级水电站辅助交通洞的绿片岩进行双轴压缩蠕变试验,将定常Burgers模型和非定常Burgers模型对蠕变试验曲线进行拟合对比分析。研究结果表明:采用非定常Burgers拟合时,拟合曲线与试验曲线基本吻合,残差平方和比采用定常Burgers模型时的小,且相关系数也有明显提高,因此,非定常Burgers模型更适用于描述硬岩的黏弹性蠕变特征。

A nonlinear viscous component whose viscous coefficient is nonlinear function of stress and time was built. This nonlinear viscous component could describe nonlinear viscous property of rock. The viscous components of Burgers model were replaced by this nonlinear viscous component, thus, modified Burgers model was obtained. The modified Burgers model was also called as non-stationary Burgers model. The comparison between Burgers model and non-stationary Burgers model was carried out by using the biaxial compression creep tests data of green schist from auxiliary tunnel at Jinping Second Stage Hydropower Station. The research results show that non-stationary Burgers model curve and experimental curve approximately coinside with each other, and the accuracy of fitting is higher than that by using Burgers model. Therefore, non-stationary burgers model is available and reasonable.