近场地震下基础隔震结构反应谱研究

发布时间：2018-07-01 19:20

本文选题：近场地震动 + 远场地震动　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：本文围绕近场地震下基础隔震结构反应谱展开研究,为了得到近场地震下基础隔震结构的弹塑性反应谱,对结构进行基于性能的抗震设计。本文通过建立单自由度弹性反应谱的运动微分方程,对于弹性体系的运动微分方程和基本公式进行了研究,提出了对反应谱研究应当集中考虑的问题。分析了隔震结构的基本原理,并结合隔震结构的特点选择了等效单质点计算模型,根据铅芯叠层橡胶支座的特性选择Bouc-Wen模型作为恢复力模型,建立了基于Bouc-Wen恢复力模型的弹塑性动力微分方程,同时对动力反应的数值计算方法进行了分析,并利用Newmark-β法对动力微分方程进行了求解。为了得到结构在地震作用下的反应谱,本文首先研究了近远场地震动的基本特征,并分析了其对结构的影响,根据近场和远场的划分原则和场地类别的划分原则,对从美国地震数据库(PEER)选取的134条地震波进行了分类,根据地震动特征周期的定义和地震动的特点,得到各类场地的特征周期和地震动水平影响系数最大值。本文对阻尼比为0.05和0.2情况下的加速度反应谱进行计算,通过对弹性微分方程的求解,得到近远场地震下各类场地的相对加速度反应谱,根据相对加速度反应谱和水平影响系数的关系建立了不同场地条件下的水平影响系数谱,利用最小二乘法对水平影响系数谱进行拟合,得到了弹性加速度水平影响系数反应谱。研究发现,近场地震下的水平影响系数最大值相比远场较大。在给定强度折减系数和阻尼比的基础上,对基于Bouc-Wen恢复力模型的弹塑性微分方程进行求解,得到近场和远场地震下三类场地条件下的等强度延性需求谱,对等强度延性需求谱进行拟合,建立R-μ-T三者的关系,利用R-μ-T关系并基于弹性加速度水平影响系数谱建立近场和远场地震下三类场地条件下的弹塑性位移谱。研究发现,近场地震下弹塑性位移谱谱值比远场谱值小,表明对近场地震下的结构进行隔震效果比远场较好。对铅芯隔震橡胶支座进行了压剪试验,并对铅芯隔震橡胶支座压剪试验的结果进行分析,由试验结果计算出支座屈服后刚度值和屈服力试验值,对液化天然气储罐进行振动台试验,将振动台试验结果与弹塑性位移谱结果进行对比,发现基于性能的反应谱分析较接近结构的实际反应,验证了本文所提出反应谱的合理性,表明本文的研究成果具有一定的工程应用价值。
[Abstract]:In this paper, the response spectrum of base-isolated structure under near-field earthquake is studied. In order to obtain the elastic-plastic response spectrum of base-isolated structure under near-field earthquake, the performance-based seismic design of the structure is carried out. In this paper, the differential equation of motion and the basic formula of elastic system are studied by establishing the differential equation of motion of single degree of freedom elastic response spectrum, and the problems that should be considered in the study of response spectrum are put forward. The basic principle of the isolated structure is analyzed, and the equivalent single mass point calculation model is selected according to the characteristics of the isolated structure, and Bouc-Wen model is chosen as the restoring force model according to the characteristics of the lead-core laminated rubber bearing. The elastoplastic dynamic differential equation based on Bouc-Wen restoring force model is established, and the numerical calculation method of dynamic response is analyzed, and the dynamic differential equation is solved by Newmark- 尾 method. In order to obtain the response spectrum of structures under earthquake action, the basic characteristics of near-far-field ground motions are studied in this paper, and their effects on structures are analyzed, according to the classification principles of near-field and far-field and the classification of sites. 134 seismic waves selected from American seismic database (per) were classified. According to the definition of characteristic period of ground motion and the characteristics of ground motion, the maximum value of characteristic period and horizontal influence coefficient of ground motion were obtained. In this paper, the acceleration response spectra with damping ratios of 0.05 and 0.2 are calculated. By solving the elastic differential equations, the relative acceleration response spectra of various sites under near-far-field earthquakes are obtained. According to the relation between the relative acceleration response spectrum and the horizontal influence coefficient, the horizontal influence coefficient spectrum under different site conditions was established. The horizontal influence coefficient spectrum was fitted by the least square method, and the response spectrum of the elastic acceleration horizontal influence coefficient was obtained. It is found that the maximum value of horizontal influence coefficient in near field earthquake is larger than that in far field. On the basis of given strength reduction coefficient and damping ratio, the elastoplastic differential equation based on Bouc-Wen restoring force model is solved, and the equivalent strength ductility demand spectrum under three kinds of site conditions under near-field and far-field earthquakes is obtained. The R- 渭 -T relation is established by fitting the demand spectrum of ductility of equal strength, and the elastic-plastic displacement spectrum under three kinds of site conditions under near-field and far-field earthquakes is established by using R- 渭 -T relation and based on the spectrum of the influence coefficient of elastic acceleration level. It is found that the spectrum of elastic-plastic displacement is smaller than that of the far-field in near-field earthquake, which indicates that the isolation effect of the structure under near-field earthquake is better than that in the far-field. The compression shear test of lead isolated rubber bearing was carried out, and the results of compression shear test of lead isolated rubber bearing were analyzed. The stiffness value and yield force test value after bearing yield were calculated from the test results. The vibration table test of liquefied natural gas storage tank is carried out. The results of shaking table test are compared with the results of elastic-plastic displacement spectrum. It is found that the performance-based response spectrum analysis is closer to the actual response of the structure, which verifies the rationality of the response spectrum proposed in this paper. It shows that the research results of this paper have certain engineering application value.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU435;TU352.12

【相似文献】