【作者】 江洋；

【导师】 石永久；

【作者基本信息】 清华大学 ， 土木工程， 2010， 博士

【摘要】 伴随着科学技术的发展和经济水平的提高,建筑结构的设计、施工技术发展迅速,国内外出现了大量跨度达到百米甚至数百米的大跨建筑结构。大跨建筑结构的支座间距很大,地震动空间效应导致不同支座处的地震动输入不一致(多点输入效应),进而导致结构地震响应与一致输入情况有较大差别。研究多点输入效应对大跨建筑结构的影响,对确保结构在地震中的安全具有重要意义。目前,对大跨建筑结构多点输入地震响应的研究仍处探索阶段,尚未建立完善的理论分析体系或设计计算方法。本文采用理论分析和数值计算等方法,对大跨建筑结构多点输入地震响应计算和抗震设计领域中的关键环节开展了较深入、系统的研究。本文主要完成了以下几方面的工作:(1)利用数值计算方法研究地震动功率谱位移特征对多点输入地震响应的影响,构造基于规范反应谱且适用于多点输入计算的实用地震动功率谱模型。(2)通过理论公式推导,提出多点地震动时程人工合成的简化方法。由简化方法合成的多点地震动时程可用于大跨建筑结构的多点输入时程分析计算。(3)基于理论分析,将静力修正方法引入多点输入动力方程的绝对位移求解法,提出修正绝对位移法,为多点输入动力方程提供了新的求解方法。(4)基于理论分析,提出多点输入虚拟激励法的实用求解方法。提出在现有通用有限元计算软件中实现多点输入虚拟激励法的思路与方法,为多点输入随机地震响应分析提供简便有效的计算平台。(5)推导简化模型多点输入地震响应功率谱解析式,研究多点输入效应对大跨结构地震响应的影响机理。根据简化模型得出的规律,提出适用于大跨建筑结构抗震设计的多点输入最不利工况的快速确定方法,指导工程设计计算。(6)提出新的评价参数和基于抗震验算内容的综合评价方法,用于评价多点输入效应对结构响应的影响程度,为提出以传统一致输入抗震设计为基础的多点输入抗震设计简化方法提供了有效工具和思路。更多还原

【Abstract】 With the development of science and technology, and the elevation of economic level, building structures’design and construction technologies have developed rapidly, which results in the appearance of many large-span building structures with a span of hundreds of meters. The distance between the restraints of large-span building structures is large, and the spatial variation of ground motion results in the discrepancy of seismic excitations between different restraints (multi-support excitation effect), which causes that the seismic response of structures under multi-support excitations is quite different from that under uniform excitations. Thus study on the influence of multi-support excitation effect on large-span building structures has a great significance for the structure safety during the earthquake. Currently, research on the multi-support excitation effects is still in the exploratory stage, and neither theoretical analysis system nor design method is perfect. By using theoretical analysis and numerical calculation, this dissertation conducts a systematic research on the seismic response analyses and design methods for large-span building structures under multi-support excitations. The main work in this dissertation includes several aspects as follows:(1) The influence of displacement characteristics of ground motion power spectral density (PSD) on the seismic response of large-span building structures under multi-support excitations has been studied by using numerical method. A practical ground motion PSD model, which is based on the code response spectrum and suitable for multi-support excitation calculation, has been built.(2) Based on theoretical formula derivation, the improvement and simplification of simulation method of spatially correlated earthquake ground motions have been proposed. The consistency between the simulated ground motions and the target PSD model has been validated by numerical examples. (3) Based on theoretical analysis, the static correction method has been introduced into the absolute displacement method for multi-support excitation dynamic equation, and the modified absolute displacement method, which provides a new method for solving the multi-support excitation dynamic equation, has been proposed.(4) Based on theoretical analysis, the Pseudo Excitation Method (PEM) has been improved into a more practical form. A realizing method in the existing finite element analysis software for PEM has been proposed, which provides a simple and effective computing platform for the multi-support excitation calculation.(5) The analytic formulae of seismic response PSD of simplified large-span structure models have been derived to study the influence mechanism of multi-support excitation effects. Based on the response law derived from simplified models, the fast method of determining the most unfavorable conditions of multi-support excitation effect has been proposed for engineering design calculations.(6) The design response ratio has been proposed to evaluate the influence of multi-support excitation effects on structure response, and the evaluation system based on seismic design has been built, which provides an effective tool for the simplification of multi-support excitation seismic design that is base on the conventional uniform excitation seismic design.更多还原