Water Guiding Tunnel Slope Stability Analysis In Right Bank In JinChuan Hydro-power Station

This paper gives a scientific analysis of many factors which influence water tunnel slope stability, being on the basisi of geological research and water tunnel slope investigation. Many fruit are in the following:(1) According to the statistic of structural surfaces of water tunnel highway slope, especially the statistics for structural surfaces in PD14,PD18 cave, a geological 3 dimentional model is found. With slices operations to the geological model, some section map in different orientations are acquired. Further research and analysis have been done.(2) On the basis of structural surfaces statistic and investigation of water tunnel slope, it finishes the work of weathering zone classification,Unloading zone classification,structure of rock mass classification,rock mass quality classificaition. The result shows that thin layers and mutual layers structure is the dominant;Due to weathering effect, the surfacial rock mass quality is grade IV, in a whole, rock mass quality of slope can be described in grade IIIa,IIIb.(3) According to geological research and investigation, destruction mechanism of failure part have been analyzed; it can be concluded that there are 4 kinds of failure mechanism along water tunnel slope, and they have been described in details in the text(4) On the basis of full investigation and research of structure of rock mass and quality of rock mass, global stability analysis has been done by using software. It shows that slope stability of water tunnel is good under differenct working conditions, although bending-toppling rock mass exist in the lower surface of slope.(5) Block mass theory has been utilized to give an slope stability analysis, it shows that there exist small unstable block rock mass in local area, but it does not do harm to the global slope stability.(6) At last, numerial simulation by using ANSYS software is utilized to give an analysis of displacement field and stress field. The simulated working condition contains 2 step, one step is natural condition and after excavation codition. It shows that unloading rebounding occurs in the place of excavation part, and rebounding orientation is to the air face. The maximum displacement get to 2.38cm. Most plastic zone and maximum displacement part are mainly along the direction of faults or intersection part of faults. Shear stress exist in the excavation berm, and simulated results are consistent with factual distribution of stress and displacement field.