Abutment Stability Analysis Of Wudongde Arch Dam Based On The Vector Sum Method

Arch dam has been widely adopted in worldwide countries for itseconomy and security. Especially in recent years, concrete high dam havea rapid development and become the mostly type of dam of large-scalereservoir and hydroelectric power station. However, arch dam has a stricterrequire about graphical and geological conditions than any other type ofdam. The stability of dam abutment should have a direct relation tofailure-free operation and security of projects, and security of downstreampeople’s life and property as well. According to incomplete figures, therewere45cases caused by spoil and other security accident aboutconstructed arch dams in the world, among them28cases were caused byabutment destabilization, so the arch dam genuine potential hazard lies inthe stability of side banks dam abutment rock mass.The methods of evaluation in stability include rigid limit equilibriummethod, strength reduction, overload law, and so on. Compared to thesemethods, the vector sum analysis method has a great advantage, it has beenproved, and has been applied in some two-dimensional analysis. But in thecomplex three-dimensional stability analysis, it has been applied rarely，especially in the arch dam abutment stability analysis.This paper use the vector sum to analyze the arch dam abutmentstability, improves the whole process from theory to complex engineeringapplications, derives its direction of the downward trend in the damabutment stability analysis, writes the procedures that extract data from thenumerical results to get the safety factor of the vector sum method. Then I provide a certain amount of results for the vector sum method to try tomake it to be the standard slope stability methods of evaluation.Based on Wudongde arch dam, first of all, I study those things thatmay affect the abutment stability. Then I analyze the actual effect of thesefactors by two-dimensional calculation to consider them in different waysin the three-dimensional model. Finally, with the combination of anti-slide,the abutment force, the arch side key position in the3-D model, I analyzethe Wudongde arch dam abutment stability under different times andconditions.Analysis showed: K25need to be reinforcement as its influence ofabutment stability; because the safety factor of the vector sum meets thestability requirements, so Wudongde arch dam abutment wedge slidingfailure do not exist under normal load and seismic load; during excavation,there are some plastic zones in the abutment which need to bereinforcement.