Study On Calculation Method Of Hydrodynamic Action Of Deep Water High Pier Cable-stayed Bridge In Reservoir Area

When the bridge in the deep water area is subjected to an earthquake,the bridge pier under the water body will vibrate and deform,and will form a relative movement with the water body.The water body in motion will mainly act on the pier in the form of dynamic pressure,and the water body will not only change its effect.The dynamic characteristics of the pier may also adversely affect the dynamic response of the pier,and these effects will persist throughout the earthquake.The current norms for the impact of ground motion water in China include the seismic design rules for highway bridges(JTG/T B02-01-2008),the seismic design codes for railway engineering(GB 50111-2009)and the seismic design codes for urban bridges(CJJ-166-2011).three standards consider the role of hydrodynamic pressure in the static method,among them,the “Code for Seismic Design of Highway Bridges”(JTG/T B02-01-2008)shows that it is mainly suitable for medium and small bridges,do not consider the E2 condition and the internal water problem of the hollow pier,the result is dangerous in the calculation of deep water high piers or long span bridges.In the "Anti-Seismic Rules for Highway Bridges"(2018 approval draft),the calculation of hydrodynamic pressure draws on foreign calculation methods on the basis of the original,not only replaces the influence of water bodies on the structure in the earthquake in the form of additional mass,moreover,the effects of water inside and outside the structure are also considered.In view of the development of relevant domestic norms and the influence of ground motion water on the piers,this paper has made the following discussion and research on the deepwater bridge in the reservoir area:(1)Introduce the research status of the interaction between water body and structure and the characteristics of seismic response of deepwater bridges and the diseases that occur under earthquake action.It summarizes the norms of dynamic water action at home and abroad and the typical calculation methods of hydrodynamic action.(2)Exploring the seismic response of solid and hollow single cantilever piers with different cross sections under earthquake action,mainly for the dynamic characteristics and dynamic response of piers under the influence of anhydrate,analyzing the different water depth ratios of bridge piers,the action directions of different seismic waves,and different The influences of the calculation method of dynamic water action on the displacement,natural vibration frequency,pier shear force and bending moment of the pier are summarized and compared with the results calculated by different dynamic water action,and the calculation differences of each method are compared.(3)Taking the deep-water high pier cable-stayed bridge in a certain reservoir area as the engineering background,the influence degree and magnitude of the dynamic hydraulic power of different water levels on the natural vibration frequency and seismic response of the bridge under the action of earthquake are discussed by the additional mass method.The cable-stayed bridge is studied.Earthquake response to seismic waves in longitudinal and transverse bridges.(4)Taking the calculation method of the inner and outer waters of the cable-stayed bridge as the research object,the internal and external water calculation methods are modified on the basis of relevant theories,and the modified calculation method is used to analyze the seismic response of the cable-stayed bridge.The seismic response of the internal and external water calculation methods before and after correction was evaluated and evaluated.(5)Through the research and comparison of the calculation methods of shaking water in various places,the difference between static calculation method and dynamic calculation method is analyzed from the perspective of static force and dynamics.