【作者】 王亚楠；

【导师】 李慧； 杜永峰；

【作者基本信息】 兰州理工大学 ， 结构工程， 2014， 博士

【摘要】 在过去的二十年里,隔震技术已经被证明是一种非常有效的抗震技术,在民用建筑、桥梁以及工业建筑中得到了广泛的应用。基础隔震技术是通过在结构底部安装具有较低抗侧刚度的隔震支座,使结构基本自振频率远离地震动的高频成分,从而减小上部结构地震作用的一种被动抗震技术。由此可见,对于能量集中分布在中、高频段的远场地震动,基础隔震技术非常有效。但是,对于包含长周期、大幅值以及高能量输入频率成分的脉冲型地震动,基础隔震技术的有效性则值得商榷。现有的研究已经表明,隔震支座在脉冲型地震作用下可能会发生屈曲、拉裂等破坏,影响上部结构的安全。为此,本文围绕脉冲型地震作用下,隔震支座的位移需求和分别采用调谐质量阻尼器和粘滞阻尼器对隔震支座位移进行控制的减震-隔震混合控制体系的动力响应、能量耗散机理以及抗震性能展开了以下几方面的研究工作：(1)对既有关于近断层区域划分以及脉冲型地震动特征的研究工作进行了总结,在此基础上建立了脉冲型地震动的选取准则,利用该选波准则从PEER中选取了本文后续工作所需的脉冲型地震记录,通过对脉冲型地震记录的功率谱进行分析,研究了其频谱特征；对现有普通地震动的合成方法以及速度脉冲的数学模型进行了总结,在此基础上通过对目标响应谱进行拟合得到了脉冲型地震动的高频分量,利用He-Agrawal模型合成速度脉冲分量,将两者进行叠加得到包含高频分量和低频分量的合成脉冲型地震动,通过对合成地震动的功率谱进行分析,探讨了该合成方法的可行性。(2)对脉冲型地震作用下隔震支座非弹性位移需求的估算方法进行了研究。建立了隔震结构弹性位移需求谱和等强度位移需求谱的相关方程,运用MATLAB进行编程和求解得到了隔震结构的弹性位移需求谱、等强度位移需求谱和等强度位移比谱；对弹性位移需求谱和等强度位移比谱的谱形特征进行了分析,利用曲线拟合方法得到了弹性位移需求谱和等强度位移比谱的计算公式,通过与真实地震记录的弹性位移需求谱和等强度位移比谱进行对比,探讨了本文所建立计算公式的合理性；最后,将弹性位移需求谱和等强度位移比谱的计算公式进行联立,得到了等强度位移需求谱的计算公式,利用该公式可以快速地估算出隔震支座在脉冲型地震作用下的非弹性位移需求。(3)分别研究了调谐质量阻尼器和粘滞阻尼器的安装对隔震支座以及上部结构地震响应的影响。建立了LRB结构、TMD-LRB体系以及Dsup-LRB体系的非线性运动方程,运用MATLAB编程求解了结构在脉冲型地震作用下的动力响应,通过与LRB结构进行对比,分别研究了调谐质量阻尼器和粘滞阻尼器的安装对隔震支座位移响应和上部结构层间位移响应和加速度响应的影响；进一步研究了速度脉冲周期、支座屈服力、屈服后与屈服前的刚度比、调谐质量比、调谐频率比以及由粘滞阻尼器产生的附加阻尼比对隔震支座和上部结构位移响应的影响；最后,建立了LRB结构、TMD-LRB体系以及Dsup-LRB体系的能量平衡方程,运用MATLAB编程求解了结构的能量响应,通过对地震动输入能、结构阻尼耗能以及隔震支座滞回耗能的对比分析,从能量耗散的角度研究了调谐质量阻尼器和粘滞阻尼器的安装能够削弱结构地震响应的原因。(4)研究了粘滞阻尼器的安装对上部结构和隔震支座抗震性能的影响。对LRB结构和Dsup-LRB体系进行非线性增量动力分析,得到了上部结构和隔震支座的IDA曲线,对单条IDA曲线和多条IDA曲线的特征进行了分析,经过统计得到上部结构和隔震支座的16%、50%和84%分位IDA曲线,从统计的角度对两者的抗震性能进行了分析；进一步对LRB结构和Dsup-LRB体系进行了地震易损性分析,得到了上部结构和隔震支座在不同极限状态下的地震易损性曲线,从概率的角度对两者的抗震性能进行了评估。(5)以串联隔震体系振动台试验为基础,对隔震支座的位移需求进行了动力试验研究。通过对不同强度地震作用下隔震支座的位移响应进行对比分析,研究了地震动强度对隔震支座位移响应的影响：通过与远场地震进行对比,研究了脉冲型地震动对隔震支座位移响应的影响；通过与LRB结构进行对比,研究了粘滞阻尼器的安装对隔震支座位移需求的影响,为数值分析结果提供了试验论据。更多还原

【Abstract】 In the last two decades, the seismic isolation technology has proved to be a very effective aseismic technology, giving rise to many applications for civil buildings, bridges, and industrial buildings. Base isolation technology is a positive aseismic technology that can keep structural basic frequency away from high frequency components of the seismic ground motion, and reduce the superstructure’s seismic action by using isolation bearing having lower lateral stiffness. The isolation bearings are installed at the bottom of the buildings. Thus it can be seen that, isolation technology is very effective under far-field ground motions, which have a large energy distribution especially for medium to high vibration frequencies. However, the effectiveness of the isolation technology is questionable under pulse-like ground motions, which have a long period, large amplitude, and high energy pulse component. Existing studies have shown that near-fault pulse-like ground motions can lead to buckling or rupture of the isolation bearings, and can influence the safety of superstructure. For these above reasons, this paper will study isolator bearing’s displacement demand, dynamic response, energy dissipation mechanism and seismic performance of the vibration reduction device-base isolation hybrid control system, as follows:(1) Existing studies on division of the near-fault region and characteristics of the pulse-like ground motions were summarized, selection rules of the pulse-like ground motions on the basis of those existing studies was established, and pulse-like ground motion records from PEER strong ground motion database were obtained using the selection rules. Frequency characteristics of the pulse-like earthquake records were studied on the basis of power spectrum. Existing studies on ordinary seismic ground motions’synthetic methods and velocity pulse model were summarized, high frequency component was generated by using spectrum matched technology, velocity pulse component was generated by using He-Agrawal model, and pulse-like ground motions were generated through superposition of the high frequency component and velocity component. Reliability of the synthetic method was studied by analyzing power spectrum of the pulse-like ground motions.(2) The estimation method of the isolation bearing’s inelastic displacement demand was studied. The equations of motion that related to base isolated structure’s elastic displacement demand spectrum and inelastic displacement demand spectrum were established. On the basis of these equations, base isolated structure’s elastic displacement demand spectrum, constant yield strength inelastic displacement demand spectrum, and constant yield strength inelastic displacement ratio spectrum using MATLAB were obtained. Spectrum characteristics of the elastic displacement demand spectrum and constant yield strength displacement ratio spectrum were studied, and fitting expressions of the elastic displacement demand spectrum and constant yield strength inelastic displacement ratio spectrum were proposed. Reliability of the fitting expressions was studied by comparing between real spectrum and fitting spectrum. At last, the estimation equation of the constant strength displacement demand spectrum was established, and the displacement demand can be obtained easily by using this equation.(3) The effect of the TMD and viscous damper on the seismic response of the supstructure and isolation bearing was studied. Nonlinear equations of motion for the LRB structure, TMD-LRB system and Dsup-LRB system were established, dynamic response of the structure under pulse-like ground motions were solved, and effect of the TMD and viscous damper on the isolation bearing displacement response, superstructure inter-story drift and acceleration response was analyzed. Moreover, influence of the velocity pulse period, bearing yield force, stiffness ratio, mass ratio, frequency ratio and additional damping ratio on superstructural and isolation bearing displacement response was studied. At last, Energy equilibrium equations of the LRB structure, TMD-LRB system and Dsup-LRB system were established, energy responses were solved, and the cause of the structural response’s reduction was studied from the perspective of energy dissipation.(4) The effect of the viscous damper on seismic performance of the superstructure and isolation bearing was studied. Nonlinear incremental dynamic analysis of the LRB structure and Dsup-LRB system was performed respectively, IDA curves were obtained. Characteristics of the single IDA curve and multiple IDA curves were analyzed.16%,50%and84%fractile IDA curves were obtained through statistical analysis. Seismic performance of the superstructure and isolation bearing was analyzed from the perspective of statistics. Moreover, Seismic fragility analysis of the LRB structure and Dsup-LRB system was conducted, the seismic fragility curves of the superstructure and isolation bearing under different limit states were obtained, and the seismic performance of the superstructure and isolation bearing was assessed from the viewpoint of probabilit. (5) On the basis of shaking table test of the series seismic isolation system, displacement demand of the isolation bearing was studied. The effect of the ground motion intensity on displacement response of the isolation bearing was studied through the comparison between the seismic responses under ground motions that have different intensity. The effect of the pulse-like ground motions on displacement response of the isolation bearing was studied through the comparison between far-field seismic responses and the seismic responses under near-fault pulse-like ground motions. The effect of the viscous damper on displacement demand of the isolation bearing was studied through the comparison between the LRB structural seismic responses and the Dsup-LRB system’s seismic responses. The test results provided a reference for the results of numerical analysis.更多还原