Research On Seismic Design Of Self-repairing Single Column Piers Based On Performance

The bridges serve as important transport facilities in earthquakes,but with the advancement of seismic research,the shortcomings of past design methods for ductile piers have become increasingly appearance,and society has put forward higher requirements for the performance of piers during and after the earthquake.The performance-based seismic design methods of foreign countries have been studied for more than two decades,which is currently one of the research hotspots in the field of bri dge seismic.At the same time,self-resetting bridge piers have received extensive attention and research due to their self-resetting function and small residual deformation.This article summarizes some of the self-resetting bridge pier structures and improves their structure.The specific research content and achievements are as follows:Firstly,the disadvantages of traditional ductile piers in earthquake resistance are analyzed.The main problems are low seismic performance,serious damage,and large residual deformation.Then the paper introduces the self-resetting pier,and introduces the development of the structure,its principle:self-repairing pier rely on the rotation of the pier protection structure,rely on energy-consuming steel consumption of seismic energy,rely on self-resetting prestressed steel and self weight to restore the original structure.The self-resetting pier has the characteristics of self-resetting and small residual displacement.Secondly,the composition of the self-resetting bridge pier is described.It is mainly introduced from five aspects:the base of the pier column,load-bearing components,self-resetting components,energy-consuming components,bridge piers and the joints,and then the domestic and foreign research on self-resetting bridge piers is summarized.,mainly from the views of theoretical research and simulation studies.The bridge seismic response analysis method and the development of seismic design ideas are summarized.Thirdly,according to the characteristics and working mechanism of the improved structure,the mechanical formula of the self-resetting single-column bridge pier is deduced.the bending performance M(?)includes self weightM_G of the pier column,self-resetting prestressed steel barsM_p,energy-consuming steel barsM_h.And according to the characteristics of each stage to point the factors,which can improve the anti-overturning and anti-rolling properties,and according to the principle of material mechanics to explain the design method of each part.Fourthly,using OpenSEES to establish a self-repairing single-column bridge pier model based on fiber beam,and apply the quasi-static reciprocating load into bridge pier model,obtain the“flag-shaped”hysteresis curve concerning the displacement of the pier top and the shear force at the bottom of the pier.This result basically verified the assumption that the self-resetting part and the energy-consuming part“in series”are combined.The hysteresis curve also reflects the small residual deformation of the self-resetting bridge piers and features a self-resetting function.Using the control variable method to change the parameters of each part for simulation analysis,summarizing its laws for design calculations,including the design of the pier section,the area and length of the energy-consuming part and prestressed part,the shear resistance of the embedded joints,and the bending resistance of the foundation.Fifth,according to the specification,three reasonable seismic waves are selected for time-history analysis.The results show that the performance requirements are basically met???_d=3%H_Z.In the second half of the seismic wave,the residual displacement of the piers of the self-returning piers is small.The self-returning pier has better performance than traditional piers.The main innovation of this paper is to reasonably increase the base of the pier column to make it more resistant to overturning,anti-rolling and self-resetting.The research shows that under the action of load,the self-repairing single-column bridge pier has the advantages of less damage,less residual deformation and self-resetting,and the design of self-resetting single-column bridge pier is reliable according to the preliminary design principle of this paper.