| With the continuous development of human society and economy,bridges play a pivotal role in human life.The frequent activities of human beings on the earth,under the action of bridge traffic load,the study of bridge lateral overturning resistance has gradually become a popular topic,and various strengthening solutions based on bridge piers have emerged incessantly.In addition,as one of the largest natural disasters on earth,the damage of bridges under the action of earthquakes is also a major problem that cannot be ignored nowadays.The article focuses on the analysis of the dynamic performance of bridges under earthquake action under the premise that they are strengthened by transverse overturning.Firstly,it introduces the current bridge transverse overturning problem and various schemes of reinforcing bridge pier types,while briefly describing the disaster situation of bridges under earthquake action,and then specifies the research content of the article;then based on the research,it introduces the seismic theory approach of bridges and determines the scheme adopted in the article,the main research contents are as follows.（1）The paper establishes two models of three-span 65 m one-column pier continuous girder bridge based on different overturning strengthening methods based on CSIBRIDGE,plus the original unstrengthened model for a total of three groups of models,firstly,the two strengthening models are tested for overturning resistance,and the transverse overturning resistance coefficients of both groups of strengthening models are greater than 2.5,and the analysis of self-oscillation characteristics is carried out under the premise of overturning resistance,and the study shows that: for the one-column The study shows that the first-order vibration frequency of the pier increases with the addition of the cover beam,while the seismic response of the regular bridge is dominated by the first-order vibration,indicating that the stiffness of the bridge becomes larger under the reinforcement of the cover beam,and the bridge with large stiffness has small deformation under the seismic action and cannot evacuate the seismic energy better.（2）Based on the previous dynamic characteristics analysis,three sets of conditions were set up by the reaction spectrum method,and the response of the three models under E1 and E2 earthquakes was compared in strict accordance with the latest seismic code.The study points out that both reinforcement methods can effectively reduce the internal force of the span cross-section under the earthquake;excluding the displacement of pier 1# in the transverse direction under the E1 condition.Under the effect of the earthquake in E1 condition,the reinforced method of adding more pillars could reduce the shift at the top of the pier and the moment at the bottom of the pier,which had an anti-seismic effect.The reinforcement method of increasing the cover beam can also play a seismic effect to a certain extent,but the effect is second to none.（3）On the basis of the response spectrum analysis,the article explains the reasons for using the time course analysis method for Class B rule bridges,and the maximum value of three sets of seismic wave calculations is used as the final result of the time course in strict accordance with the code regulations.In addition,through nonlinear time calculations,it can be seen that the reinforced model pier section will enter the plastic hinge state,but its plastic angle of rotation is much smaller than the ultimate allowable angle of rotation,the seismic capacity to meet the requirements of the design specifications,the reinforcement method has a certain degree of engineering credibility.Figure [76];Table [33];reference [63]... |
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