Study On Seismic Structure System Of Cable-bounded Bridge Piers

At present,natural disasters are increasingly harmful to human survival and social development.Earthquakes have been listed as the first of many natural disasters because of their abrupt and massive destructive power.The bridge project is one of the lifeline projects for earthquake relief,and it plays a vital role in safeguarding the smoothness of highways during the disaster relief work in the event of natural disasters.The early construction of existing highway bridges has the problem of insufficient seismic resistance of piers,foundations,and bearings.The traditional method of seismic strengthening of bridges is mainly local reinforcement of components or seismic isolation measures,although it can improve the seismic resistance of bridges.The cost is large,the efficiency is low,and the reinforcement is time consuming.It is inevitable that the bridge will be affected by the normal operation of the bridge when it is reinforced.In particular,the internal force of the pile foundation cannot be improved for the difficult position such as the bridge pier foundation.In order to achieve this goal,this paper designed a cable-restrained pier anti-seismic system,that is,set engineering cables at the pier piers to restrain the seismic deformation of bridge piers,solve the earthquake-resistance problem of the bridges without increasing the amount of bridge piers,in order to reduce the pier and The purpose of basic earthquake internal forces.This paper studies the seismic performance of the system under different parameters.The main research contents and conclusions are as follows:(1)Firstly,the type of bridge damage and seismic strengthening measures in earthquake are analyzed in detail,and the basic principles and limitations of existing reinforcement methods are clarified.(2)The concept of anti-seismic system for cable-bounded bridge piers is put forward,the design concept and implementation scheme are explained in detail,and the preliminary judgment of the anti-seismic performance of the system is made.(3)The anti-seismic mechanism of the cable restrained pier system was analyzed and the rationality of the system was determined.By simulating a large number of cable restraint systems to reinforce concrete simply-supported girder bridges and continuous girder bridges under different conditions,two calculation methods,the response spectrum and the time-history,were adopted.Through numerical analysis,the internal forces of the structure before and after the bridge reinforcement were obtained.The analysis results show that the displacement and internal force of the bridge pier under the same conditions of earthquake are significantly improved before the reinforcement with the cable restrained pier system reinforcement.The recommended range of the reasonable cable cross-sections for different pier heights and spans is given to maximize the seismic performance of bridge structures under optimal economic conditions.(4)Based on this,an actual girder bridge is taken as an example to illustrate that the cable restrained pier system proposed in this paper can significantly reduce the pier and the internal force of the foundation.It can meet the E1 earthquake under the action of the structure in the elastic state and the E2 earthquake does not produce excessive displacement of the pier.Requirements,and refer to the relevant specifications for the measurement of the structural system pricing,drawing conclusions on economic feasibility.(5)The bridge anti-seismic structure proposed in this paper is simple and novel,which proves that the proposed method is basically applicable in the actual reinforcement project,and can provide some references for such projects in the future.