大跨斜拉桥多维多点地震激励减震控制方法分析

Analysis of earthquake mitigation control method for large-span cable-stayed bridge under multi-component multi-support earthquake

首先利用SIMULINK仿真工具箱建立了大跨度斜拉桥在多维多点地震激励下的半主动减震控制分析模型.然后采用拟合规范反应谱的多点人工地震动时程,研究并比较分析了一致激励以及同时考虑行波效应和部分相干效应等激励工况下,行波波速以及部分相干程度对斜拉桥减震效果的影响规律.数值结果表明:无论是有控还是无控结构,考虑多点激励后,主梁中跨跨中出现较大竖向位移和轴力,且竖向位移随着行波波速的减小和部分相干程度的减弱呈增大的趋势;行波效应和部分相干效应总体上对减震效果的影响很小;主动和半主动控制算法控制效果接近,优于始终提供最大阻尼力的被动控制算法.

First,the semi-active earthquake mitigation control model of large-span cable-stayed bridge under multi-component multi-support earthquake is established using SIMULINK toolbox. Then,artificial multi-support earthquake time histories compatible with code response spectrum are simulated,and the influence of wave-passage velocity and the extent of incoherence to the mitigation rates is studied under uniform excitation and multi-support excitation considering wave-passage and incoherence effect together. The results show that considering multi-support excitation,large vertical displacement and axial forces occur with or without control devices. The vertical displacement increases along with the decreasing of wave-passage velocity and the extent of incoherence. Generally,good mitigation rate can still be obtained considering wave-passage and incoherence effect together. Active and semi-active control algorithms are similar in control effectiveness,and always superior to passive control algorithm with the maximum damping forces.