Finite Element Method Analysis Of High Arch Dam Pre-Stressed Pier With Submodeling Method

The U type pre-stressed pier of a high arch dam is the research object of this paper.The characteristics of this structure are as follows:the design water level is high, water thrust that the gate received is enormous;outlet gate pier is gigantic cantilever and the dam body corresponded is thin comparatively,there is no slot between dam and pier,dam stress is relatively gigantic; in order to meet the request of hydraulics the ratio of height to width for inlet and outlet is different,thus the orifice stress is greatly influenced by dam body stress; downstream cantilever is longer and the support structure of arch-gate is dimensional structure composed of pier and beam. The structure is so complex that it is difficult to simulate; relative to other pre-stressed pier anchor style, research on the function mechanism and numerical simulation of U style pier is less nowadays.This paper ulteriorly discuss the mechanism of U style anchor based on researches of other investigators, and bring forward an effective numerical simulation method. Pervious researches on arch dam pre-stressed pier has a problem that the boundary condition is too simple to reflect the influence of dam body stress and foundation. This paper analyse a high arch dam pre-stressed pier with submodeling method. Also investigated work characteristics and stress distribution law under different cases, summarized stressing specialty and stress distribution rule of key structure part through calculating two schemes by submodeling method and conventional simplified boundary model. It offers references for pier structure's optimization and arrangement of main, secondary anchor cable.In contrast to traditional calculation method, submodeling method can gain more accurate numerical value for the concerning region of model, enhance calculation accuracy, make it possible to compute huge complex hydraulic structure model, and take account of dam body stress and foundation influence effectively through comparison of two schemes. This method is an effective approach to numerical simulation for huge complex hydraulic structure. Outlet flank in the front of U type anchoring area appear larger tensile stress without prestress through submodeling method calculation, this tensile stress exceeds tensile strength of concrete. This paper find out the reason through comparative analysis of verification scheme. U type anchor pier merely embed loop steel tube to form hole, which hardly weaken stressing section of dam body, furthermore the stress distribution around loop anchor is more symmetrical than that around straight line anchor cable of silo contrary tensile. So this is the effective method to simulate high arch dam outlet pier and can be reference for similar project design.