Seismic Response Analysis Of High Intake Towers With Oblique Incidence Of Seismic Wave

With the construction of a batch of hundred meter dams in turn,the construction height of the corresponding diversion and water conveyance structure intake tower group also increases,while the seismic intensity in the western region is high and strong earthquakes occur frequently,which is difficult to avoid when selecting the location of water conservancy projects,which brings great challenges to the seismic safety of intake tower group.At present,in the dynamic response analysis of high-rise intake tower group,the boundary condition is usually considered as fixed boundary.The incident mode of seismic wave is assumed to be vertical,but the incident direction of shallow seismic wave is uncertain.The seismic response generated by the structure also changes with the incident direction of seismic wave.Therefore,it is assumed that the incident mode and fixed boundary conditions of the vertical incident seismic wave are not completely consistent with the actual situation,and the errors caused by them cannot be ignored.In order to study the influence of oblique incidence of seismic wave on the dynamic response of high-rise water intake tower group,this paper establishes the model of high-rise water intake tower group through the finite element software,introduces the viscoelastic artificial boundary and the seismic input method of different incident angles of seismic wave,and analyzes the influence law of different incident angles of seismic wave on the dynamic response of high-rise water intake tower group.The specific research contents and results are as follows:(1)Equivalent boundary force method is used to realize wave input on viscoelastic artificial boundary and oblique incidence of SV wave.Based on the calculation method of the equivalent load of each node on the artificial boundary when SV wave is incident obliquely in two and three dimensions,the calculation program of the equivalent node load under the action of SV wave is compiled,and the corresponding numerical example model is established.The calculation results show that the calculation program and method have high accuracy.The finite element model of the towering water intake tower group was established,and the seismic response of the towering water intake tower group was calculated and analyzed when the SV wave incident at different incident angles ? and ?.The results show that the oblique incidence of SV wave significantly changes the displacement,acceleration and stress response of the intake towers,and has a negative effect on the structure of t he towering intake towers.(2)Based on the calculation method of the equivalent load of each node on the artificial boundary when P-wave incident obliquely in two and three dimensions,the calculation program of the equivalent node load under the action of P-wave is compiled,and the corresponding numerical model is established.The calculation results show that the calculation program and method have high accuracy.The finite element model of the towering water intake tower group was established,and the seismic response of the towering water intake tower group was calculated and analyzed when P wave incident at different incident angles ? and ?.The results show that the oblique incidence of P wave significantly changes the displacement,acceleration and stress response of the intake towers and has a negative effect on the structure of the towering intake towers.(3)Through the above analysis and research,it can be seen that oblique incidence of seismic SV wave and P wave has a certain degree of influence on the dynamic response of high-rise intake tower group,which is significantly different from the vertical incidence of seismic SV wave and P wave and has a negative impact on the structure.In view of this,in the structural design of high-rise intake tower group,it is necessary to consider the adverse effect of oblique incidence of seismic wave on the structure.