混合梁斜拉桥随机地震响应分析

发布时间：2018-04-23 21:09

本文选题：混合梁斜拉桥 + 随机振动　；参考：《西南交通大学》2015年硕士论文

【摘要】：近些年,斜拉桥发展迅速,跨度也由几百米增大到千米级,而随着跨度的增大,其抗震设计也变得复杂,因此对其进行地震分析十分必要。地震具有明显的随机性,采用随机振动法对斜拉桥进行抗震分析显然是合理的。论文利用有限元分析软件ANSYS,以鄂东大桥为工程背景,采用随机振动分析法计算分析了混合梁斜拉桥在一致激励和非一致激励下的地震响应,并通过结构地震响应的功率谱探讨了结构地震响应的机理。计算结果表明,纵向一致激励下,结构的顺桥向响应较大,其余两个方向的响应很小；横向一致激励下时结构的响应特点与纵向一致激励时相似,仅是横桥向响应较大；竖向一致激励时,除竖向响应较大外,结构的顺桥向响应和横向响应也较大；三维一致激励下结构的地震响应比一维一致激励时明显要大。对结构的非一致激励分析主要考虑了行波效应、部分相干效应和局部场地效应,计算结果表明,考虑行波效应后结构的地震响应有所下降,对抗震设计有利；考虑部分相干效应后的结构响应比不考虑相干效应时响应明显要大,而比完全相干时的响应稍小；考虑局部场地效应后结构的响应和一致激励时的响应相差很小,说明局部场地效应结构的地震响应影响不明显。无论是一致激励还是非一致激励,混合梁斜拉桥总是边跨混凝土梁段内力响应大位移响应小,而中跨钢梁段内力响应小位移响应大。同时本文通过结构响应功率谱分析,确定了各工况下结构各响应的控制振型,阐明了结构的地震响应机理。
[Abstract]:In recent years, the cable-stayed bridge has developed rapidly and the span has also increased from several hundred meters to a thousand meters. With the increase of the span, the seismic design of the cable-stayed bridge is also complicated. Therefore, it is necessary to carry out seismic analysis of the cable-stayed bridge. The earthquake has obvious randomness. The seismic analysis of the cable-stayed bridge by random vibration is obviously reasonable. The software ANSYS, taking the Eastern Hubei bridge as the engineering background, uses the random vibration analysis method to calculate and analyze the seismic response of the mixed girder cable-stayed bridge under the uniform and non uniform excitation, and discusses the mechanism of the structural seismic response through the power spectrum of the structural seismic response. The results show that the bridge direction response of the structure is better under the longitudinal uniform excitation. The response of the other two directions is very small; the response characteristic of the lateral uniform excitation structure is similar to that of the longitudinal uniform excitation, only the transverse response of the bridge is larger; the vertical response and the lateral response of the structure are larger except the vertical response. The seismic response of the structure under the three dimension uniform excitation is more than one dimension one. The results show that the seismic response of the structure is decreased after considering the traveling wave effect, and it is beneficial to the seismic design, and the response of the structural response to the partially coherent effect is compared to the response without consideration of the coherent effect. The response of the structure to the local site effect is very small, and the response of the local site effect structure is very small. It shows that the effect of the seismic response of the local site effect structure is not obvious. The response of the mixed beam cable-stayed bridge is always larger than that of the concrete beam. The response of the middle span steel beam is small, and the response of small displacement in the middle span steel beam is large. At the same time, through the analysis of the structural response power spectrum, the control mode of the response of the structures under various working conditions is determined and the seismic response mechanism of the structure is clarified.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U448.27

【参考文献】