近断层地震动合成方法及其对超大跨斜拉桥地震响应影响

发布时间：2018-05-28 08:10

本文选题：桥梁工程 + 近断层地震动合成　；参考：《中国公路学报》2017年02期

【摘要】：为研究具有破裂前方效应和滑冲效应的2类脉冲型地震动对超大跨斜拉桥不利响应的影响,提出近断层脉冲型地震动合成的"分解-叠加"新方法,从频谱特性及结构地震响应两方面对该方法的有效性进行了验证。以苏通长江公路大桥为研究对象,分析了脉冲周期、脉冲速度峰值、脉冲数等参数对超大跨斜拉桥地震响应的影响规律。结果表明:近断层地震动高频成分对结构的响应不容忽视,"分解-叠加"法能够反映近断层地震动高频成分及低频脉冲成分对结构响应的贡献;具有滑冲效应的低峰值脉冲可激起主塔的高阶阵型,破裂前方效应地震动主要激起主塔的基本振型;当破裂前方效应和滑冲效应复合作用且两者同时达到脉冲峰值时,结构地震响应最为显著;脉冲速度峰值对斜拉桥主塔内力和位移等响应影响显著;不同脉冲周期的地震动作用下,滑冲效应引起斜拉桥地震响应明显高于破裂前方效应;脉冲个数为奇数的地震动较偶数的地震动对结构响应影响更为显著。
[Abstract]:In order to study the influence of two types of impulsive ground motion with fracture forward effect and slip effect on the adverse response of super-large span cable-stayed bridge, a new method of "decomposition-superposition" for near-fault pulse type ground motion synthesis is proposed. The validity of the method is verified in terms of spectral characteristics and structural seismic response. Taking Sutong Yangtze River Highway Bridge as the research object, the influence of pulse period, pulse velocity peak value and pulse number on the seismic response of super-large span cable-stayed bridge is analyzed. The results show that the response of the high frequency components of near-fault earthquake to the structure can not be ignored, and the "decomposition-superposition" method can reflect the contribution of the high-frequency components and the low-frequency pulse components of the near-fault earthquake to the structural response. The low peak pulse with slip effect can excite the high order formation of the main tower, the ground motion of the front effect of rupture mainly excites the basic mode of the main tower, and when the forward effect of rupture and the slip effect are combined and both of them reach the peak value of the pulse at the same time, The seismic response of the cable-stayed bridge is the most remarkable, the peak value of the pulse velocity has a significant effect on the responses of the main tower of the cable-stayed bridge such as internal force and displacement, and the seismic response of the cable-stayed bridge caused by sliding impact is obviously higher than that of the forward effect of rupture under the action of different pulse periods. The effect of the odd number of pulses on the structural response is more significant than that of the even number of ground motions.
【作者单位】：东南大学混凝土及预应力混凝土结构教育部重点实验室;上海市政工程设计研究总院(集团)有限公司;
【基金】：国家自然科学基金项目(51378110) 江苏省“六大人才高峰”项目(JZ-007) 东南大学优秀博士学位论文培育基金项目(YBJJ1611) 江苏省研究生科研创新计划项目(KYLX15_0086)
【分类号】：U442.55;U448.27

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