【作者】 安栋；

【导师】 梁建文； 屈铁军；

【作者基本信息】 天津大学 ， 防灾减灾工程及防护工程， 2013， 博士

【摘要】 根据建筑抗震加固规程，部分地区对原有未进行抗震设计的砖砌体房屋进行了抗震加固，多采用外加钢筋混凝土梁柱的加固方法，目前这些房屋仍在正常使用。这些砖砌体房屋能否达到我国现行规范的抗震设防目标需要进一步研究。地震动的非平稳性表现在强度和频率两个方面，目前研究多为地震动强度的非平稳性，对频率非平稳性的研究还不充分。频率非平稳性对结构地震反应有多大的影响还没有结论。本文的研究旨在评价不同砖砌体结构的抗震性能和外加钢筋混凝土梁柱砖砌体结构的加固效果，并通过拟动力试验研究地震动的非平稳性对砖砌体结构地震反应的影响。本文设计制作了三类砖砌体房屋，外加钢筋混凝土梁柱进行抗震加固的砖砌体结构、按现行规范要求设置构造柱和圈梁的砖砌体结构以及未采取抗震设防措施的普通砖砌体结构，每类房屋分别输入频率平稳和非平稳的地震加速度时程，完成了六个近似足尺模型的动力特性试验、拟动力抗震试验和拟静力抗震试验。本文试验采用的两种地震动输入，一种是人工合成强度非平稳频率平稳的地震加速度时程，另一种是强度和频率都具有非平稳特性的真实强震记录。为使试验结果具有可比性，对真实强震记录进行调整，保证两种输入的峰值加速度相等，峰值出现时间相近，阿里亚斯强度和谱强度相近。通过动力特性试验，得到了房屋的自振频率、振型和阻尼比，比较三类结构自振特性的异同。通过拟动力试验，研究了不同地震动输入下结构的地震反应，包括位移、加速度、恢复力等，还研究了相同地震动输入下不同结构的地震反应特性。通过拟静力试验，得到了六个模型的滞回曲线、骨架曲线、刚度退化曲线以及极限承载力和极限位移等，研究不同结构的变形性能、刚度退化和破坏形态等，并采用无量纲表示以及归一化回归分析方法研究了三类砌体结构的骨架曲线和刚度退化规律。此外，本文还讨论了采用相位差谱和时变功率谱两种方法合成非平稳地震动的可行性，对生成的地震加速度时程进行短时傅里叶变换分析，讨论了这两种方法的合成效果，以供工程应用参考和后续研究。更多还原

【Abstract】 According to current technical specifications, seismic strengthening of thebuildings was applied for masonry buildings which designed without adequatedetailing following seismic code in parts of country. Masonry strengthening with RCbeam-column was mostly used. These buildings are available at present. Whetherthese strengthened masonry buildings can satisfy the seismic fortification criterionneed to be further studied. The non-stationarity of earthquake motion is shown both inamplitude and frequency content. Current research on non-stationarity is mostly intime domain, meanwhile non-stationarity in frequency domain has not been fullystudied. The effect of non-stationarity on the structural seismic response has not beenstudied comprehensively. This thesis wants to assess seismic behavior of masonrybuildings and evaluate the retrofit effect of masonry strengthened with RCbeam-column. The influence of non-stationary characteristics on masonry seismicresponse is analyzed using pseudo-dynamic test.Three groups of brick masonry buildings were designed and constructed, includingmasonry strengthened with RC beam-column, masonry with tie-column andring-beam according to the requirements of present codes, common masonry withoutseismic fortification measures. The earthquake motions with frequency stationarityand non-stationarity are taken as seismic input in each group of masonry. Totally, sixapproximate full-size models of masonry buildings were constructed and dynamiccharacteristics tests, pseudo-dynamic tests and pseudo-static tests have carried out.In this thesis, two kinds of earthquake motion input were adopted. One is artificialsynthesized earthquake acceleration time-history with amplitude non-stationary butfrequency stationary. The other is real strong motion record with non-stationarity bothin amplitude and frequency. In order to contrasting the test results, adjustments to theoriginal record are made to ensure that peak value of the two acceleration time-historyis equal, the time reaching the peak is similar, and arias intensity and spectral intensityare close.Through dynamic characteristics tests, natural frequencies, damping ratios andmode shapes of the six masonry buildings were obtained. The similarities anddifferences of dynamic characteristics of three types’ masonry were concerned. Pseudo-dynamic tests of homogeneous structure under different earthquake motioninput were carried out to compare and investigate the structural response includingdisplacement, acceleration, restoring force. Seismic response of different structureunder same earthquake motion were analyzed and contrast. The hysteretic cures,skeleton curves, stiffness degradation curves, maximum resistance and ultimatedisplacement of the buildings were obtained from pseudo-static tests of the sixmasonry buildings. The deformation capacity, stiffness degradation and failure patternof different structure were contrasted and studied. The method of non-dimensionalrepresentation and normalized regression analysis are provided in the skeleton curvesand the stiffness degradation.Also, this article discusses the feasibility of using two methods of phase differencespectrum and evolutionary power spectra to synthesize non-stationary earthquakemotion. The Short-time Fourier Transform (STFT) of the simulated earthquakeacceleration time-history was analyzed. The issues in synthesis effects of the twomethod can be for the engineering application and further research.更多还原