砂化岩体在开挖干扰下弹塑性损伤数值模拟

以连续介质力学和不可逆热力学为基础,求解砂化岩体损伤演化方程,并将损伤引入到修正的弹塑性本构方程中,提出了适用于砂化岩体的弹塑性损伤三维有限元计算方法.该方法反映砂化岩体在开挖施工干扰下的岩体破坏过程.应用该方法进行数值模拟计算了坪头水电站引水隧道1#竖井开挖过程,分析成果与实际情况较为吻合,验证了该分析方法的合理性,为砂化岩体计算提供了理论依据.

Numerical analysis ofsandificated rock masses under the disturbance of excavation based on elastoplastic damage model

Based on the irreversible thermodynamics and nonlinear continuum mechanics, the damage evolution equation of rocks sandification is suggested and a new elastoplastic damage model with elastoplastic constitutive equation is presented. Furthermore, three dimensional elastoplastic damage finite element numerical modeling iterating method for sandificated rock masses is put forward. Based on this method, the damage process of sandificated rock due to the disturbance of surrounding rock during shaft excavation is considered. The presented method is applied to the excavation of No.1 shaft of seepage tunnel at Pingtou hydropower station. By making comparison with calculation results and in situ observations, the rationality of this method is proved and the results are helpful for the design of sandificated rocks in similar projects.