摘要
针对当前研究隔震曲线梁桥地震可靠度时无法充分考虑地震动随机性和多维性的现状,从全概率角度出发,系统研究了隔震曲线梁桥在多维随机地震作用下的抗震性能,建立双质点六自由度隔震曲线梁桥简化模型并推导其非线性运动方程,通过引入工程地震动加速度功率谱随机模型,采用谱表示-随机函数法生成符合同一集合系统的多维非平稳地震动时程样本,将该样本作为输入隔震曲线梁桥的随机激励,采用四阶龙格-库塔法求解得到隔震曲线梁桥结构的动力时程数据,利用TVD差分格式求解其广义概率密度演化方程来量化地震持时内结构动力响应的概率信息,然后构造极值随机过程得到隔震曲线梁桥下部结构和隔震层的位移极值分布函数和系统可靠度,结果表明:考虑非平稳随机地震激励的多维性会放大隔震曲线梁桥结构的动力响应;概率密度演化法求解隔震曲线梁桥这类强非线性结构的动力响应表现优越;通过调整隔震曲线梁桥桥面宽度和曲率半径的合理取值,能够提升隔震曲线梁桥的抗震性能.
In response to the current situation where the seismic reliability of seismic-isolated curved girder bridges cannot fully consider the randomness and multidimensionality of seismic motion,this paper systematically studies the seismic performance of seismic-isolated curved girder bridges under multi-dimensional random seismic action from thea perspective of full probability.A dual particle,six-degree-of-freedom model of a seismic-isolated curved girder bridge is established and its nonlinear motion equations are derived.By introducing a stochastic model of the engineering seismic acceleration power spectrum,the spectral representation seismic-isolated random function method is used to generate multidimensional non-stationary vibration time history samples that conform to the same set system.The seismic acceleration time history samples are used as the random excitation input for the seismic-isolated curved girder bridge.The fourth-order Runge-Kutta method is used to obtain the dynamic time history data of the seismic-isolated curved girder bridge structure,and the TVD difference scheme is used to solve its generalized probability density evolution equation to quantify the probability information of the structural dynamic response during earthquake duration.Then,an extreme value stochastic process is constructed to obtain the displacement extreme value distribution functions and system reliability of the lower structure and isolation layer of the seismic-isolated curved girder bridge.The results indicate that considering the multidimensionality of nonstationary random seismic excitation amplifies the dynamic response of seismic-isolated curved girder bridge structures.The probability density evolution method shows superior performance in solving strongly nonlinear structural systems such as seismic-isolated curved girder bridges.By adjusting the reasonable values of the bridge deck width and curvature radius of the seismic-isolated curved girder bridge,the seismic performance of the seismic-isolated curved girder bridge can be improved.
作者
李喜梅
范朋辉
李万润
LI Ximei;FAN Penghui;LI Wanrun(Western Engineering Research Center of Disaster Mitigation in Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Institute of Earthquake Protection and Disaster Mitigation,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《湖南大学学报(自然科学版)》
北大核心
2025年第11期190-200,共11页
Journal of Hunan University:Natural Sciences
基金
国家自然科学基金资助项目(52268028)
甘肃省国际科技合作基地开放基金资助项目(GⅡ2023-D02)。
关键词
概率密度演化法
谱表示-随机函数法
多维非平稳激励
动力可靠度
隔震曲线梁桥
probability density evolution method
spectral representation-random function method
multidimensional non-stationary excitation
dynamic reliability
seismic-isolated curve girder bridge
