摘要
为了研究耐震时程法对于预应力钢管混凝土自复位桥墩桥梁地震响应捕捉的可行性,拓展其在结构领域的研究范围,进行了此方法在配有无黏结预应力桥墩桥梁的地震适用性分析。以一座采用预应力钢管混凝土桥墩的典型四跨连续梁为研究对象,在OpneSees软件中建立其三维有限元模型,并采用通过与增量动力分析(IDA)结果对比的方法,验证了ETM预测自复位桥梁地震响应的可行性;在可行性验证基础上,进一步采用耐震时程法分析了桥墩中引入预应力对自复位桥梁体系地震响应的影响。结果表明:耐震时程法可用于进行预应力自复位桥墩桥梁结构抗震性能评估,其能较好地预测出自复位桥梁结构的预应力大小和残余位移等地震响应。墩柱中的预应力对桥梁地震响应的影响与支座形式和地震动强度有关,对于上部结构,预应力能够减小主梁位移,但会增大固定支座的剪力;对于下部结构,顶部为滑动支座的墩柱受预应力影响较小,而顶部为固定支座的墩柱会因施加预应力而显著增大地震内力。因此,在进行此类桥梁抗震设计时,需综合考虑结构体系布置和桥址处地震基本烈度。
In order to investigate the feasibility that ETM captures the seismic performance of self-centering bridges incorporating prestressed concrete-filled steel tube(CFST)piers and expand its research scope in structural field,the applicability analysis of ETM in the bridge structures with unbonded posttensioned piers is conducted.A 3D finite element model of a typical 4-span continuous beam bridge which adopts prestressed CFST piers is established by OpenSees software.By the method that comparing with the incremental dynamic analysis(IDA)result,the feasibility of ETM to predict the seismic response of self-centering bridges is also verified.Based on the feasibility analysis,the influence of prestressing force in piers on the seismic performance of self-centering bridge systems is further studied by ETM.The result shows that(1)ETM can be used in the seismic evaluation of bridges with prestressed self-centering piers.The seismic response,such as prestressing force and residual displacement,can be well predicted by using this method.(2)The influence of prestressing force in piers on the seismic response of bridges is related to the type of bearings and the intensity of earthquakes.For the superstructure,the displacement of main girder can be reduced by prestressing force,but the shear forces of fixed bearings will be increased accordingly.For the substructure,the piers with sliding bearings on the top are less influenced by prestressing force,while the piers with fixed bearings on the top will significantly increase the seismic internal force due to prestress.Therefore,it is necessary to comprehensively consider the structural system arrangement and basic seismic intensity at site during seismic design of such bridges.
作者
杜晓雷
葛华
DU Xiao-lei;GE Hua(Zhejiang Institute of Communications Planning,Design and Research,Hangzhou Zhejiang 310006,China;PowerChina Sichuan Electric Power Engineering Co.,Ltd.,Chengdu Sichuan 610041,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2021年第10期82-91,99,共11页
Journal of Highway and Transportation Research and Development
关键词
桥梁工程
抗震分析
耐震时程法
无黏结预应力桥墩桥梁
数值仿真
OPENSEES
bridge engineering
seismic analysis
endurance time method(ETM)
bridge with unbonded prestressed piers
numerical simulation
OpenSees
