The Stability Analysis Of High-rock Slope On The Right Bank Spillway Tunnel Of Luding Hydroelectric Station

The Luding hydroelectric power station located at the Luding county of Sichuan Ganze Tibetan Autonomous Region, the dam site is approximately 40km apart from Kangding, approximately 2.5km apart from Luding, approximately 300km apart from Chengdu. The right bank of dam is concave and bedrock exposed. The high-rock slope got a big problem with downstream against flush, anti-flush. This article mainly talk about the high-rock slope of 2# and 3# exports of spillway tunnel at right bank, below 1420m elevation terrain slow, the natural slope higher than 300m. The concrete research results are as follows.1. This article established the slope three-dimensional model first, carried on a Fast Lagrangion Analysis of Continue method, analysis the stress and strain. The result indicated that this slope belongs to the shallow layer glide, the glide belt mainly located at the surface layer, and the slope body got a tendency of gliding toward left underneath.2. After overall stress and strain analysis, this article carried on established the two-dimensional finite element analysis at the export slope of soft intercalated layer. Had known through the analysis this soft intercalated layer existence's position and the angle, greatly released the spillway export slope's stability, and was playing the control action.3. Had certain understanding after the slope overall stability, this article splits seven relative dangerous sections, uses the limit equilibrium method and the strength—reduction method with FEM calculates its safety factors during excavate, rainning, earthquake, an so on. By the comparison between strength—reduction method and Sarma method, we concluded that strength—reduction method not only has good accuracy in engineering application, but also has a great advantage in searching slippery fractures(this paper searched two slippery fractures with same safe factors). These results enable us to evaluate the stability of the slope accurately and then more easily optimize the engineering treatments.4. Through the above analysis, we know that slope is stable at natural state, but under raining or earthquake the slope close critical state, possible glide. Therefore this article proposed to the slope engineering treatments, then check the safety factors, the result had indicated that after the supports and protections slope was at the steady state, the engineering treatment entire feasible, also economic, has achieved the expectation effect.