Stability Analysis And Research Of Support Measures For High-Steep Massive Rocky Slope

In this paper, based on the National Electric Power Company's major project: stability analysis and research of support measures for right bank of Yalong River Jinping I Hydropower Station( The inlet of water diversion and power generation system discharge buildings, switching station, high line concrete system and the Houzi Slope ), study the stability analysis and the research of support measures for High-steep massive rocky slope and get the research results as follow:(1) On the basis of summarize of failure mode research of massive rocky slope, bring up the potential failure mode of massive rocky slope, that is: the plane failure and the wedge failure. Then analyze the geological data which has been already known, figure that the failure mode of the Intake Slope on the right bank of Jinping I Hydropower Station is wedge failure.(2) Ordinarily, qualitative analysis of wedge failure is stereographic method. In this paper we use the equal surface projection to apply the geological data on the sterographic projection. Use the modified Markland method to analyze the sterographic projection and estimate the potential failure mode of the slope. In this way, we can cut down the interfere improve the efficiency of stability analysis of rock wedges.(3) Hoek Theory was the first and the famous analysis theory on the rock wedges' stability, it use the limit equilibrium method, assume that every slip surface is plane, the force is decomposed into three dimension and the Safety Factor is the ratio of the total sliding resistance and the total downward sliding force. Because the Jinping I Hydropower Station is located in the Southwest of China, in this area earthquake take place frequently. So we need to consider the earthquake force when we analysis the stability of rock wedges. Unfortunately the Hoek Theory didn't calculate the effect of earthquake force in his formula, thereby we can't use the Hoek Theory directly and need to do some modification. In this paper, firstly the author use the ordinary method in the Criterion to calculate the earthquake force. Then use the principle of the Hoek Theory, decompose the earthquake force. Project it and compose into the the total sliding resistance and the total downward sliding force. At last deduce a modified Hoek formula, which has considered the effect of the earthquake, to analyze the stability of rock wedge slope.(4) The prestressed anchorage cables is widely used in slide slope support. There is two main problems during the design of the prestressde anchorage cables: anchorage force of the prestressed anchorage cables and the length of the anchorage segment. This paper has discussed the two problem, especially discuss the length of the anchoring segment in the case of the anchoring segment drill through the different rock which has different t — limit shear stress between the borehole wall and the cement mortar. The application example shows that the length of the anchoring segment drill through the different rock is longer that through the single rock, but the total length of the prestressed anchorage cables is shorter. It has definite economy means.