AN ANALYSIS OF PLANE FAILURE OF ROCK SLOPES BY QUANTIFIED STEREOGRAPHIC PROJECTION

摘要

At the present, stereographic projection is one of the most widely used methods used to evaluate rock slope stability. However, the results of stereographic projection is not quantifiable, so it is difficult to apply the result to the technical designing of rock slopes. In order to solve this difficulty, and by using the limit analysis method, we quantified the results of stereographic projection method with safety levels valued differently in the daylight envelope , which represents the failure risk area in the net. Dip and dip direction of discontinuities are changed by the pole location in the daylight envelope and thus, the volume and the weight of failure rock block, shear force and shear stress working in the failure face are changed. The results from the calculation of the safety factors in the daylight envelope revealed a remarkable difference in slope stability. After the stability-similar area was evaluated, a contour was drawn up and the stereographic projection for the plane failure was quantified by dividing the safety level into five separate grades. The proposed quantified stereographic projection was verified by field application.