大跨度斜拉桥边墩横向抗震体系研究

发布时间：2018-09-19 09:53

【摘要】：为了给大跨度斜拉桥边墩横向抗震体系设计提供依据,讨论了减震体系的合理性,并研究了减震体系的适用范围。首先,针对横向全滑动体系,分析了梁端横向位移的控制振型,推导了边跨主梁横向基本周期的简化计算公式,并利用反应谱法,推导与简化了地震下梁端横向位移的计算公式,通过与有限元计算结果对比,验证了其可靠性。然后,依据实际项目工程经验,通过合理简化与假定斜拉桥结构参数,在工程精度允许范围内,进一步对计算公式进行简化。最后,以主跨跨径与地震动输入为主要变量进行共计384个工况的计算,分析了各工况下梁端最大横向位移,得到了不同跨径下横向全滑动体系斜拉桥在不同场地类型与不同峰值加速度(PGA)下的梁端最大横向位移变化规律。研究结果表明:以梁端横向位移为抗震目标时,对于Ⅲ,Ⅳ类场地,各PGA作用下,主跨跨径大于400m的斜拉桥均需考虑采用减震体系;对于Ⅰ,Ⅱ类场地,PGA不大于0.1g,主跨跨径不大于600m的斜拉桥可以不考虑采用减震体系;其中,如果结构的抗震能力大于地震需求,建议采用全限位体系;如果结构的抗震能力接近或小于地震需求,且梁端横向位移不控制时,则建议采用全滑动体系。
[Abstract]:In order to provide the basis for the design of lateral seismic system of side pier of long-span cable-stayed bridge, the rationality of the system is discussed, and the applicable range of the system is studied. First of all, the control mode of transverse displacement of beam end is analyzed, and the simplified calculation formula of lateral basic period of side span main beam is deduced, and the response spectrum method is used. The calculation formula of transverse displacement of beam end under earthquake is deduced and simplified, and its reliability is verified by comparing with the results of finite element calculation. Then, according to the actual project engineering experience, the calculation formula is further simplified by reasonably simplifying and assuming the structural parameters of cable-stayed bridge and within the scope of engineering accuracy. Finally, the main span and the input of ground motion are taken as the main variables to calculate a total of 384 working conditions, and the maximum transverse displacement of the end of the beam under each working condition is analyzed. The variation of maximum transverse displacement at the beam end of the cable-stayed bridge with transverse sliding system under different spans under different site types and different peak acceleration (PGA) is obtained. The results show that when the transverse displacement of the beam end is taken as the seismic target, for the sites of type 鈪，

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