西藏邦铺矿区花岗岩剪切流变本构研究及其开挖边坡长期稳定性分析

岩体的破坏主要是沿着破坏面滑移的压剪破坏,对西藏邦铺矿区花岗岩岩样进行不同法向应力下的剪切流变试验。通过分析其剪切流变试验曲线,并基于Burgers模型,引入了一种改进非线性牛顿体黏壶,进而提出了一种改进的Burgers剪切流变模型,并利用该流变模型辨识的参数,应用于西藏邦铺矿区开挖边坡长期稳定性分析。结果表明:(1)改进的Burgers剪切流变模型,能够很好地拟合岩石流变的3阶段,对加速流变阶段的拟合结果很理想,具有较好的实用性;(2)开挖边坡稳定性分析时,考虑流变长期作用后,开挖边坡中部台阶区域位移变大,应力也发生变化,应加强该区域的支护和预警措施。

Granite shear rheological constitutive research of Bangpu mining area in Tibet and its excavation slope stability analysis for a long time

The destruction of the rock mass is the compression-shear damage that mainly along the shear failure surface. Granite shear rheological experiment in Bangpu mining area in Tibet was carried out. The shear test curve is analyzed and an improved nonlinear Newton components is introducted based on the Burgers model; and then a modified Burgers shear rheological model has been put forward. The stability of the excavation slope at Bangpu mining area is analyzed for a long time by using the new model's parameters. The results show that, (1) The modified Burgers shear rheological model can fit well the three stages of the rock rheology, especially for the accelerating rheological stage, has a well practicability. (2) The excavation slope's displacement is heightened and the stress is also changed in central steps area when considering the rheological long time effect; support and early warning measures should be strengthened in the area.