A numerical study on the cumulative out‐of‐plane damage to church masonry façades due to a sequence of strong ground motions          下载免费PDF全文

Siro Casolo 《地震工程与结构动力学》2017,46(15):2717-2737

Seismic shocks occur sometimes as a sequence, close in space and time, of destructive events of comparable intensity. In these cases, a significant portion of the damage to historical buildings can be related with the cumulated damage on structures that become progressively more vulnerable. This research investigates the specific increase of damage determined by a sequence of strong ground motions, focusing the interest on the out‐of‐plane response of 2 church masonry façades. The dynamic analyses were performed by a specific rigid body and spring model RBSM, which only accounts for out‐of‐plane damage mechanisms. Two idealized models of façade, each made of 2 different masonry bonds, have been studied by applying various sequences of recorded accelerograms. The results highlighted a complex relationship between the spectral content of the seismic shocks and the characteristics of the structures that change in the course of the loading sequence due to the development of damage. The Housner spectral intensity proved to be a reliable scalar measure of the ground motion destructiveness for these façades. Moreover, when considering a design‐consistent accelerogram that causes a relevant damage pattern, ie, with a significant elongation of the effective first period of vibration, the numerical results indicated a possible spectral intensity threshold below which the occurrence of repeated seismic shocks, both before and after the reference design shock, can be considered as irrelevant. On the other hand, a catastrophic increase of damage should be expected when this threshold is overcome.  相似文献   

R/C frame–infill interaction model and its application to Indonesian buildings          下载免费PDF全文

Maidiawati  Yasushi Sanada 《地震工程与结构动力学》2017,46(2):221-241

This paper proposes a new analytical model for masonry‐infilled R/C frames to evaluate the seismic performance considering R/C frame–infill interactions. The proposed analytical model replaces masonry infill with a diagonal compression strut, which represents distributed compression transferred between frame and infill interfaces. The equivalent strut width is presented as a function of the frame–infill contact length, which can be evaluated by static equilibriums related to compression balance and lateral displacement compatibility at the frame–infill interfaces. The proposed analytical model was verified through comparisons with experimental results obtained for several brick masonry‐infilled R/C frames representing a typical R/C building with nonstructural masonry infill in Indonesia. As a result, good agreements were observed between the experimental and analytical values of the lateral strength and ductility of the infilled frames. The seismic performances of two earthquake‐damaged R/C buildings with different damage conditions were evaluated considering infill effects by applying the proposed analytical model. Consequently, the nonstructural brick masonry infill significantly affected the seismic resistances of the buildings, which seemed to lead to differing levels of damage for each building. These results indicate that the proposed analytical model can be an effective tool for more precisely screening earthquake‐vulnerable existing R/C buildings in Indonesia. Copyright © 2016 The Authors. Earthquake Engineering & Structural Dynamics Published by John Wiley & Sons Ltd.  相似文献   

Improved evaluation of inelastic displacement demands for short‐period masonry structures          下载免费PDF全文

Gabriele Guerrini  Francesco Graziotti  Andrea Penna  Guido Magenes 《地震工程与结构动力学》2017,46(9):1411-1430

This work discusses the simplified estimation of earthquake‐induced nonlinear displacement demands as required by nonlinear static procedures, with particular attention on short‐period masonry structures. The study focuses on systems with fundamental periods between 0.1 and 0.5 s, for which inelastic amplification of the elastic displacement demand is more pronounced; hysteretic force‐displacement relationships characteristic of masonry structures are adopted, because these structures are more commonly found within the considered period range. Referring to the results of nonlinear dynamic analyses of single‐degree‐of‐freedom oscillators, some limitations of the Eurocode 8 and Italian Building Code formulations are first discussed, then an improved equation is calibrated that relates inelastic and elastic displacement demands. Numerical values of the equation parameters are obtained, considering the amount of hysteretic energy dissipation associated with various damage mechanisms observed in masonry structures. Safety factors are also calculated to determine several percentiles of the displacement demand. It is shown that the proposed equation can be extended to more dissipative systems. Finally, the same formulation is adapted to the estimation of seismic displacements when elastic analysis procedures are employed. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

墙体开洞影响下房屋砖砌体结构地震易损性分析   总被引：2，自引：0，他引：2       下载免费PDF全文

黄艺  王睿喆 《地震工程学报》2019,41(3):574-580

为获取可靠的墙体开洞影响下房屋砖砌体结构地震易损性分析结果,采用ABAQUS有限元分析软件构建房屋砖砌体结构墙体模型,设置合理的墙体模型参数和数值模拟参数;对比模拟数值与以往研究的测试值,证明所构建模型参数取值合理;将截取的峰值段江油地震波作为上述模型的地震动输入,根据测得的房屋砖砌体结构的力学变化数据,分析房屋砖砌体结构的地震易损性。分析结果表明:地震情况下,随着墙体开洞率的增加,墙体荷载能力下降、墙体水平承载力增长幅度降低、墙体相对刚度退化率增加;墙体开洞数量越多,房屋砖砌体结构侧向刚度下降越快。因此分析得出墙体开洞率大、墙体开洞数量多,房屋砖砌体结构的地震易损性越显著。  相似文献   

多层砖房底部两层框架抗震变形性能分析          下载免费PDF全文

杨建华  叶郁 《地震工程学报》2019,41(5):1141-1146,1176

为实现多层砖房底部两层框架结构的加固,需要研究其抗震变形性能。以某底部两层框架、上部四层砖房建筑为对象,通过STRAND7有限元软件构建有限元计算模型,考虑水平荷载与垂直荷载,深入分析多层砖房底部两层框架抗震变形性能。仿真结果表明,建筑结构振型受结构横向楼板刚度的影响较显著,不同振型的频率变化中,X向1阶频率与Y向2阶频率变化最快,楼板平面内弯曲频率变化最慢;整体结构在X向与Y向分别呈现线性剪切变形和弯剪变形,Y向上由于填充墙发挥抗震墙功能,底部两层框架变形较小;在7度多遇地震影响下,底部两层结构中第二层楼板变形较第一层严重,多层砖房底部两层框架建筑结构处于弹性工作状态。  相似文献   

基于BIM的建筑砌体结构抗震性能评估方法研究          下载免费PDF全文

胡瑛  裴利剑  韩春秀 《地震工程学报》2019,41(1):221-226

建筑砌体结构抗震性能评估,对建筑结构安全的稳定性至关重要。本文从四个方面分析建筑砌体结构抗震性能提升的条件,根据建筑结构的抗震性影响因素,评估抗震能力。构建建筑砌体结构抗震性能的评估BIM指标体系;利用BIM模型中的三角模糊数,定量计算建筑砌体结构抗震性能指标的模糊判断矩阵,得到建筑砌体结构的三角模糊数值,分析筑砌体结构抗震性能指标的单排序情况,结合对建筑砌体结构抗震性能评估体系指标权重系数和单项得分的计算,实现基于BIM的建筑砌体结构抗震性能评估。结合模拟建筑实例分析,利用建筑结构倒塌概率测试建筑砌体结构的抗震性能,并利用评估结果与实际评估结果的拟合度测试提出方法的准确性。实例结果证明,能够准确的得到抗震性能的评估结果。  相似文献   

砖砌体单轴压缩与拉伸应力应变关系          下载免费PDF全文

肖遥  底欣欣  黄河 《世界地震工程》2019,35(1):210-219

砖砌体是被广泛应用的建筑材料,大量学者对砖砌体的压缩和拉伸行为特性以及应力-应变关系进行了试验研究。研究发现:砖砌体表现出与混凝土相近的应力-应变关系,为基于混凝土应力-应变关系模型发展砖砌体的应力-应变关系模型提供了基础。对已经提出的几种不同的砖砌体应力-应变关系模型进行了比较,通过比较分析,基于中国混凝土应力-应变关系模型,推荐了可用于估计砖砌体单轴压缩和拉伸载荷下应力-应变曲线的简单分析模型,模型中使用的参数不仅可以很容易地通过实验获得,而且常在规范中被规定使用。  相似文献   

无筋砌体农居地震弹塑性有限元研究          下载免费PDF全文

付亚男  熊礼全  闫磊  苏启旺  蔡高创  程龙飞  郭远臣 《世界地震工程》2019,35(4):018-32

利用ABAQUS软件对既有的砌体墙试验结果进行了数值模拟,验证了模型的正确性以及混凝土损伤塑性模型对模拟砌体结构受力性能的可用性。在此基础上,借助实地调查获得的结构参数和材料性能数据,以重庆典型农居建筑为例,建立了无筋砌体农居的三维有限元模型,对数值模型进行了动力特性分析和不同烈度下多遇及罕遇地震的动力弹塑性时程分析,并建议了无筋砌体结构农居在不同地震烈度破坏下墙体表面积受拉损伤率的临界值。最后,利用既有文献提出的层间位移角限值,分析了该农居的破坏程度,比较了墙体表面积受拉损伤率和层间位移角限值衡量砌体结构的破坏程度。分析结果表明:提出的墙体表面积受拉损伤率和层间位移角限值衡量砌体结构破坏程度吻合良好;当墙体表面积受拉损伤率小于1%时,结构轻微破坏;当位于1%~5%时,发生中等程度破坏;当位于5%~30%时,发生严重破坏;当大于30%时,结构倒塌。  相似文献   

北京历史文化街区建筑第五立面特征分析     

陈品祥  张翼然  贾光军  陶迎春  祝晓坤  左效刚 《测绘通报》2019,(12):128-131

历史文化街区及其房屋建筑是重要的历史文化资源,需要有效的保护和利用;同时又是城市的有机组成部分,需要持续的更新和发展。本文从历史街区保护的角度着眼,以北京市老城范围内历史文化街区建筑物肌理及第五立面特征为研究内容,对建筑物的第五立面色彩及形态特征、临时建筑的分布及演变等进行了分析。加强对第五立面的规划管控,在对历史文化传统风貌保护、实现旧城有机更新,提高北京老城居住环境和生活品质的目标等方面发挥作用。  相似文献   

Comprehensive Assessment of Sustainable Tourism-oriented Revitalization in a Historic District: A Case Study of Qianmen Area,Beijing, China     

ZHU He  WANG Jingru  ZHANG Xiyue 《资源与生态学报(英文版)》2019,10(5):559-568

Tourism-oriented revitalization of historic districts has been identified as a form of sustainability which is believed to contribute to both conservation and development. Comprehensive assessments of the effects of such tourism-oriented revitalizations in historic districts are thus a great challenge, and are needed to support sustainable development and management efforts. In this study criteria and indicators were identified by using the AHP method with experts scoring four aspects on two levels. We assess a case in China using this system and outputs indicated infrastructure and environment performed best, while the score for residents’ living condition and participation was the lowest. Finally, we offer some suggestions to improve the relatively poor status in order to assist historic districts in achieving sustained revitalization.  相似文献