竖向不规则结构基于延性抗震设计法的基础研究

发布时间：2018-01-13 19:05

本文关键词：竖向不规则结构基于延性抗震设计法的基础研究　出处：《华南理工大学》2014年博士论文　论文类型：学位论文

【摘要】：竖向不规则布置是导致建筑结构地震损伤破坏的主要原因之一，国内外学者针对竖向不规则结构的地震损伤破坏特点、地震反应规律以及抗震设计方法开展了广泛的研究。然而，竖向不规则结构抗震性能研究是一项十分重要且复杂的课题，虽然目前的研究已取得很大的进展，但随着建筑形式以及社会经济的发展，研究尚不完善。本文综合考虑结构竖向不规则、近断层速度脉冲地震作用、结构侧移模式等因素，针对建筑抗震设计中急需解决的几个问题进行了探索性研究。主要工作如下： (1)竖向布置规则剪切型结构的延性折减系数(DRF)研究。通过调整等效单自由度(SDOF)体系DRF,研究多自由度体系(MDOF)的DRF。以剪切型集中质量MDOF体系模型为分析对象，通过非线性动力时程分析，研究MDOF体系因高模态延性需求集中而影响抗震DRF的规律。结果表明：MDOF体系DRF比其相应的等效SDOF体系的DRF小,系统位移延性和振动周期是影响MDOF的DRF之修正系数的主要因素。 (2)近断层速度脉冲地震作用下竖向不规则结构的抗震需求变化规律研究。选取8条近断层速度脉冲地震记录，通过非线性动力时程分析，研究速度脉冲地震效应和结构底层刚度、强度以及两者组合竖向不规则的综合不利情况下，结构的位移、位移延性和能量需求变化规律及其沿楼层的分布模式。结果表明：速度脉冲型地震作用下竖向不规则结构有更大的延性需求；底层强度不规则比底层强度和刚度组合不规则对结构最大层间延性需求的影响大，，底层刚度不规则时延性需求则表现出不同规律；底层竖向不规则引起底层位移需求和能量需求急剧加大，形成塑性变形和耗能集中的薄弱层，而其它楼层位移和能量需求有减小趋势。 (3)剪切型竖向不规则结构DRF的研究。通过修正参考竖向规则结构的DRF，研究竖向不规则结构在速度脉冲强震作用下的DRF。采用集中质量剪切型MDOF模型，构建了竖向规则结构的DRF应用于竖向不规则结构时修正系数的研究方法，并探讨了主要影响因素。结果表明，竖向不规则结构的DRF明显小于参考规则结构的DRF；修正系数随着不规则比率减小或延性需求增大而减小。通过比较得出，速度脉冲地震作用下修正系数比相应非速度脉冲地震作用下修正系数值小。 (4)弯曲型与剪切型MDOF体系的抗震DRF的差异比较以及竖向强度不规则弯曲型结构的DRF研究。以多质点系悬臂柱模拟弯曲型结构、抗侧串联弹簧系统模拟剪切型结构，研究楼层位移延性和基本振动周期对弯曲型结构DRF的影响，并比较其与剪切型结构DRF的差异。通过修正竖向规则结构的DRF来研究不规则弯曲型结构的DRF，并探讨楼层数、延性、不规则比率和速度脉冲地震效应对修正系数的影响。结果表明：弯曲型结构的DRF比剪切型结构的DRF总体上约大40%；楼层数和延性水平是影响DRF的重要因素；竖向强度不规则结构的DRF明显小于其相应规则结构的DRF，修正系数随不规则比率的减小而减小；速度脉冲地震作用工况下的修正系数比非速度脉冲地震作用工况下的修正系数小，且速度脉冲地震效应与不规则比率有显著交互影响。 (5)基于蒙特卡罗模拟分析量化RC框架结构竖向不规则极限参数的抗震控制效果。以底层和中间层楼层承载力和刚度不规则的5层和10层RC框架结构为分析对象，考虑地震动输入的随机性，通过非线性动力时程分析确定结构最大层间位移，并分析其随竖向不规则参数变化的规律和超越极限状态标准的失效概率。结果表明：承载力和刚度不规则对结构最大层间位移的影响较大，最大层间位移随竖向不规则系数的减小而增大，底层不规则比中间层不规则的影响大，承载力不规则比刚度不规则的影响大；竖向不规则对结构超越极限状态水准的失效概率有显著的影响，失效概率随竖向不规则系数的减小而增大。 (6)地震动持时效应对结构抗震阻尼折减系数的影响研究。采用简谐正弦波和集集地震记录，基于SDOF体系不同阻尼比水平的位移反应谱研究了有效地震动持时对阻尼折减系数影响。结果表明：阻尼折减系数随有效地震动持时比和简谐激励循环数的增加而减小；基于分析结果的统计平均值，通过非线性回归分析给出了考虑地震动持时影响的阻尼折减系数谱。
[Abstract]:Vertical irregular layout is one of the main causes of earthquake damage of building structure, domestic and foreign scholars on the failure characteristics of vertical irregular structure of earthquake damage, seismic response law and seismic design method has carried out extensive research. However, the vertical irregular structure seismic performance research is a very important and complicated issue, although the research has made great progress, but with the development of architectural forms and social economy, the research is still not perfect. Considering the vertical irregular structure, near fault velocity pulse earthquake, lateral displacement mode and other factors, aiming at some problems need to be solved in the seismic design of buildings was studied. The main work is as follows:
(1) ductility rules of vertical arrangement of shear type structure coefficient (DRF). By adjusting the equivalent single degree of freedom (SDOF) system of DRF, the research of multi degree of freedom system (MDOF) to the DRF. shear lumped mass MDOF system model as the analysis object, the nonlinear dynamic time history analysis, the research of MDOF system for the high modal ductility demand concentrated and influence the seismic regularity of DRF. The results show that the equivalent SDOF system MDOF system DRF than the corresponding DRF system, displacement ductility and vibration period are the main factors that influence the correction coefficient MDOF of DRF.
(2) the near fault pulse under earthquake vertical irregular structure seismic demand changes. A total of 8 near fault velocity pulse seismic records by nonlinear dynamic time history analysis of velocity pulse seismic effect and the underlying structure of the stiffness, strength and the two groups combined adverse situation of vertical irregular structure. The variation of displacement, displacement ductility and energy demand and its distribution pattern along the floor. The results show that the velocity of pulse type earthquake under the action of vertical irregular structure has greater impact ductility demand; the underlying strength and stiffness than the irregular bottom layer strength irregular structure of maximum story ductility demand from the bottom, just the degree of irregular ductility demand showed a different pattern; the bottom vertical irregularity caused by bottom displacement and energy demands increase rapidly, the formation of plastic deformation and energy dissipation concentrated thin The weak layer, and the other floor displacement and energy demand has a decreasing trend.
(3) the research of shear type vertical irregular structure DRF. By modifying the structure of the DRF vertical reference rules, the research of vertical irregular structure in the velocity pulse under strong earthquake DRF. using the lumped mass shear type MDOF model, constructed the DRF application of the vertical rule structure research method of correction coefficient on vertical irregular structure. And the main influence factors were discussed. The results show that the vertical irregular structure of DRF is significantly less than the reference rule structure DRF; correction coefficient decreases with the decrease of ductility or irregular ratio increased demand. Through the comparison, the speed of impulse correction coefficient under earthquake than the corresponding non velocity pulse seismic coefficient is small.
(4) DRF DRF study on difference of seismic bending and shear type MDOF system and the comparison of vertical bending strength irregular structure. The multi particle system simulation of bending of cantilever column type structure, lateral shear type structure simulation series spring system, influence of floor displacement ductility and the fundamental vibration period on the bending type structure of DRF, and compared with the shear type structure of DRF difference. By modifying the structure of the DRF to study the rules of vertical irregular bending type structure of the DRF, and to explore the floor number, ductility, irregular pulse rate and speed of earthquake effect on the impact of the correction coefficient. The results show that the bending type structure DRF shear type structure DRF is generally about 40%; the number of floors and the ductility level is an important factor affecting the strength of DRF; vertical irregular structure DRF is much less than the corresponding rule structure of DRF correction coefficient with irregular ratio decreases with the reduction of The correction coefficient of velocity pulse seismic action is smaller than that of non velocity impulse seismic operation, and the velocity pulse seismic effect has a significant interaction with the irregular ratio.
(5) Monte Carlo simulation analysis of seismic control effects of quantitative RC frame structure of vertical irregular limit parameters based on the bottom and middle floors. The bearing capacity and stiffness of irregular 5 layer and 10 layer RC frame structure as the research object, considering the randomness of earthquake ground motions, determined by nonlinear dynamic time history analysis the maximum displacement between layers, and the analysis with vertical irregular parameter changes and the failure probability exceeding limit state standards. The results show that the influence of bearing capacity and stiffness of the irregular structure of the maximum drift greatly, reduce the maximum interlayer displacement with vertical irregular coefficient increases, irregular bottom effect than the middle layer of irregular, irregular bearing capacity than the effect of stiffness irregular; vertical irregularity has a significant effect on the failure probability of structure beyond the limit state level, the failure probability of the vertical irregular Then the coefficient decreases and increases.
(6) to study the seismic effects to the seismic response time structure damping reduction factor. The harmonic sine wave and the Chi Chi earthquake records, SDOF system with different damping ratio, displacement response spectra of the effective level of ground motion duration on damping reduction factor based on impact. The results show that the damping coefficient decreases with the increase of effective seismic reduction when the ratio and the number of cycles of harmonic excitation decreases; the results of statistical analysis based on average, by nonlinear regression analysis is presented considering damping reduction factor spectra reduction effects of ground motion duration.

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU352.11

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