It is first raised that safety coefficient can be calculated by using the widths of yieldzone and pillar, and the steps of designing the strip mining size are pro-posed.
The results show that the failure of dam foundation is caused mainly by the extension of dam heel crack and the expansion of shear-yieldzone of the foundation rock near the dam toe.
结果表明，坝基的破坏主要表现为坝踵裂缝的延伸和坝趾附近基岩剪切屈服区的扩展。
3
The traditional method which focuses on displacement, stress and yieldzone has some difficulties in stability and reinforcement analysis during excavation in underground engineering.