Impact Analysis Of Arch Dam Abutment And The Bottom Of The Dam Thickened On Body Dam Stress

Structural stress analysis of arch dam is an important part of arch dam design, especially for high arch dams of large scale, technically difficult and beyond design specifications. A large number of engineering experience shows that the lmaximum principal stress of arch dams often appear in the arch abutment and dam bottom, especially the tensile stress caused the abutment instability or even dam-break. In this paper, combined with a high arch dam,aiming at the problem that the arch and the dam bottom stress exceed the allowable value of the dam, the influence of the arching angle and the upper and lower thickening measures on the dam stress are studied. A comprehensive thickening scheme is proposed to meet the design requirements of arch dam.This paper introduces the current development situation of arch dams in China, and the technical route of the paper is put forward. Three - dimensional finite clCement model of arch dam is established by ANSYS and the simulation schceme is studied. This aper summarizes the calculation and realization of the finite element equivalent stress method of arch dam, and introduces the load application method of hydrostatic pressure,silt pressure, uplife, pressure,gravity, thrust of radial gate and so on. The problem of gache angle in arch dam structure design of high arch dam project is studied, while analyzing the influence of the cutting angle on the arch dam structure,with no gache angle program made stress contrast analysis in the two kinds of conditions. "The results show that gache angle measure of arch dam abutment can effectively reduce the arch abutment stress.Secondly, three different thickening positions of arch dam foundation are studied, the stress condition of upstream foundation thickened, downstream foundation thickened, and both upstream foundation and downstream foundation thickened analyzed under the different working conditions. It is concluded that the downstream thickening scheme of dam bottom can effectively reduce the dam bottom stress. And the thickening size of dam bottom downstream thickening scheme of is optimized, that is, the stress comparison is carried out at Om, 3m,6m and 9m. The calculation results show that the arch dam bottom is 6m thickening downstream and the stress at the bottom of the dam can meet the design requirements.And finally the comprehensive scheme of the abutment cut corners and the bottom of the dam thickend is out forward. That is, the upstream gache angle thickness at dam abutment is 2 meters, the downstream gache angle thickness at dam abutment is 2.8 meters; within the elevation of 501 to 510 meters, the dam is thickened downstream by 6 meters. And the dam body stress of arch dam under the five kinds of working conditions is calculated. The calculation results show that the stress of the arch dam can meet the design requirements of the arch dam, according to the comprehensive thickening schemes.