Research On The Seismic Influence Of The Sediment At The Bottom Of The Reservoir On The Arch Dam Under The Oblique Incidence Of Seismic Waves

In the past twenty years is a golden period in the history of China’s hydropower,a large number of high dams from each big basin stands up one after another,especially in the abundant hydropower resources in the western region has many world famous water conservancy project.However,we should also know that the western part of China belongs to the earthquake prone area,and the earthquake intensity is generally the highest in the western region,and the strong earthquakes occur frequently.Water conservancy engineering earthquake has special significance,Once a crash occurs,it will not only endanger the project itself,but also produce a series of secondary disasters,which will cause incalculable losses to the residents downstream of the dam and will bring challenges to the seismic safety of the dam.This paper studies the impact of seismic waves from different incident angles and sediment sediment on the dam earthquake.The main research contents are as follows:(1)This paper first studies how to use finite element to solve the problem of fluctuation,finite element analysis is used as the main means to establish the finite element model of arch dam,reservoir water and sediment.Due to the seismic action,the reservoir water shock will produce an additional force on the dam body,and the hydrodynamic pressure will act on the dam in turn.The whole process reflects the strong fluid solid coupling effect under the earthquake action,so the FSI module is used to calculate in the ADINA simulation.and study the setting of viscoelastic artificial boundary in the finite element model of arch dam.At the same time introduces the twodimensional viscoelastic boundary and three-dimensional viscoelastic boundary,research the method of seismic wave oblique incidence,realize the seismic wave with different incident Angle oblique incidence and oblique incidence of seismic wave decomposition into cross the river and along the river.(2)In arch dam model selection of dam crest,dam bottom,left and right abutment of several representative reference points,according to the size of arch dam model is established to determine a reasonable thickness of silt.and the seismic response displacement of the X and Y directions of each reference point in different incident angles is analyzed.Then in the dam axis upstream and downstream the dam for five reference points selected principal stress response analysis,prove that different incident Angle have influence on dam displacement and principal stress,and establish one of the most adverse incident Angle.(3)According to the most adverse incident angle,and then to reservoir sediment as a variable,then compare consider reservoir sediment and don’t consider reservoir sediment two situations,respectively in arch dam on the finite element model to select the same reference point,and then compare the two cases of displacement and the maximum principal stress changes.through the analysis of reservoir sediment on the seismic response of arch dam has certain effect.At the same time,some substantial suggestions on the construction of water conservancy projects can be put forward according to the conclusion.It is of great significance to the seismic resistance of hydraulic structures.