硬脆岩的非线性粘弹塑性流变模型

Viscoelasto-plastic Rheological Model for Brittle Hard Rock

为了构建适合于硬脆岩的流变模型,通过对Bingham体中的线性粘滞体进行修正,使其粘滞系数转换为时间、应力的衰减函数,将修正的Bingham体与六元件线性粘弹性流变模型组合得到可反映加速蠕变的非线性粘弹塑性流变模型,并采用锦屏一级水电站工程左岸边坡砂板岩的蠕变试验曲线对所建立的非线性粘弹塑性流变模型进行验证.研究结果表明:当采用非线性粘弹塑性流变模型对试验曲线进行拟合时,试验曲线与理论曲线吻合得比较理想,显示了所建模型的正确性和合理性.

In order to build an appropriate rheological model for brittle hard rock, a nonlinear viscous component, whose viscous coefficient was decay function of stress and time, was built to replace the viscous component of Bingham model, and a modified Bingham model was obtained. The nonlinear viscoelasto-plastic rheological model for hard rock was obtained based on the modified Bingham model and sixcomponent linear viscoelastic model. With this new nonlinear viscoelasto-plastic rheological model, the accelerated creep property can be studied. Finally, this new model was verified by creep test curve of sandstone from left bank slope at Jinping First Stage Hydropower Station. The research results show that the new nonlinear visoelasto-plastic rheological model curve and experimental curve approximately coinside with each other, which verifies that the new nonlinearvisoelasto-plastic rheological model is of high accuracy.