两自由度滑移隔震体系的上部结构最大地震反应分析  

Maximum seismic response of superstructure of two degree of freedom sliding base system

作　　者：胡红松 徐礼文 林凡 高毅超[1,2] 郭子雄 HU Hongsong;XU Liwen;LIN Fan;GAO Yichao;GUO Zixiong(College of Civil Engineering,Huaqiao University,Xiamen 361021,China;Key Laboratory for Structural Engineering and Disaster Prevention of Fujian Province,Xiamen 361021,China)

机构地区：[1]华侨大学土木工程学院,福建厦门361021 [2]福建省结构工程与防灾重点实验室,福建厦门361021

出　　处：《建筑结构学报》2023年第1期23-32,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51608210,51878303);福建省自然科学基金项目(2019J06016)。

摘　　要：基础滑移隔震是提高高烈度区村镇低层建筑抗震能力的有效方法。通过输入大量地震波,对两自由度滑移隔震体系上部结构归一化峰值伪加速度进行了数值分析,研究地震动和结构特性对滑移隔震结构最大地震反应的影响,并建立了上部结构峰值伪加速度的简化计算公式。研究结果表明:归一化峰值伪加速度随着上部结构周期的增大呈先增大后减小的变化趋势,可近似保守地取归一化峰值伪加速度平均值的最大值作为滑移隔震结构的最大地震反应;滑移发生后,震级、震中距及近场脉冲对结构响应的影响较小,动静摩擦系数差异的影响也可忽略不计;场地条件对上部结构响应有一定影响,表现为场地土越软,结构响应越大,但这一影响总体上随着归一化地面峰值加速度的增大而减小;对于给定的场地类别、质量比和归一化地面峰值加速度,归一化峰值伪加速度基本服从正态分布。基于参数分析结果,建立了归一化峰值伪加速度平均值与变异系数的简化计算公式,公式计算结果与简化模型计算结果吻合较好,可用于计算任意超越概率下的归一化峰值伪加速度值。Sliding base(SB) system is an efficient system for protecting low-rise buildings in high-seismic rural areas. By using a large number of ground-motion records, the normalized peak pseudo-acceleration(NPPA) of a 2-degree-of-freedom(2 DOF) sliding base system and its dependency on various structural and ground motion characteristics are investigated in this study;based on the numerical results, simplified equations were developed for estimating the NPPA. The NPPA first increases and then decreases as the natural period of the superstructure increases;the responses at the period of the maximum mean NPPA can be used to represent the responses of SB structures in real practice. The earthquake magnitude, source-to-site distance and near-fault pulses have little effect on the superstructure response after sliding occurs. The effect of possible difference between the static and kinetic friction coefficients is also negligible. Local site conditions affect the superstructure response, with softer site soil leading to larger NPPA;however, this effect decreases rapidly as the normalized ground motion intensity increases. For a given site class, mass ratio and normalized ground motion intensity, the NPPA approximately follows a normal distribution. Simplified equations with associated values of the regression coefficients were proposed to estimate the mean values and coefficients of variation(COVs) of NPPAs. The proposed equations can accurately estimate the computed values based on the response history analysis.These equations can be further used to predict the value of NPPA corresponding to any probability of exceedance.

关 键 词：滑移隔震体系 峰值伪加速度 地震反应 参数分析 场地条件 

分 类 号：TU352.12[建筑科学—结构工程]