三峡工程中陡高边坡的分层开挖模型

研究了三峡大坝陡高边坡的开挖方案及坡面稳定性问题；通过对陡高边坡简化模型的分析，运用刚体平衡法、Bishop法对滑体进行受力分析，完成最危险滑动面的搜索，计算了相应的安全系数，构建了均匀岩体边坡的优化开挖模型，并对开挖坡角进行了优化；结合三峡工程的实际背景，进一步考虑了岩体风化的分层，提出了陡高边坡的分层开挖模型，给出了各层最优开挖角及安全系数的计算公式，得到了边坡的整体开挖方案；数值结果表明：陡高边坡的分层开挖模型是较均匀的开挖模型，稳定性增加，结果更符合工程实际。

A Mathematical Model of Stratified Excavation of Steep-high Slope in the Three Gorges Project

The scheme of excavation of the steep high slope of perpetual shiplocks and the stability of the mountain body in the Three Gorges Project are studied. A simplified model of the steep high slope is analyzed.The methods of Bishop and rigid body equity is used respectively. During the course, several variables are selected to search the latent dangerous gliding sides and its corresponding safety factor is computed. A optimal excavation model of uniform rock slant is established and the optimal excavation angle is obtained. Furthermore, the efflorescent phenomenon of rock stratification is considered. Based on the background of the Three Gorges Project, a stratified excavation model of the steep high slope is built. The optimal excavation angle of each stratification, its safety factor and the scheme of the integrated excavation are obtained. The numerical example indicates that the stability of stratified excavation model is improved comparing with the optimal model of uniform rock slant.