检索结果-内蒙古大学图书馆

Seismic Performance of Coupled Shear Walls Designed according to old and New codes and Retrofitted with Eb-CFRP Composites

引用

JOURNAL OF EARTHQUAKE ENGINEERING 2022年第4期26卷 1875-1898页

作者： Honarparast, Sara Chaallal, Omar Univ Quebec Dept Construct Engn Ecole Technol Super Montreal PQ Canada

Coupled shear walls (CSW) are an efficient lateral load-resisting system. Their seismic performance depends primarily on their coupling beams (CBs) ability to provide adequate stiffness and strength. However, many existing buildings with CSW resisting system were designed and constructed according to old codes and standards with insufficient requirements for seismic design. These systems feature unsatisfactory behaviour and prematurely collapse in case of major earthquake events. Therefore, their seismic retrofit is urgently needed. The main objectives of this study are, i) evaluate and compare the seismic performance of CSWs designed to old and new codes;ii) highlight the deficiencies of CSWs designed to old codes;iii) investigate a retrofit method using externally bonded (EB) carbon fibre reinforced polymer (CFRP) composites to enhance the seismic response of deficient CSWs. To that end, a 20-story CSW is considered with different design details including one according to old National Building code of Canada (NBCC) before the 1970s and the other one designed consistent with the new NBCC 2015 and the Canadian Standard Association, CSA A23.3-14, for Eastern seismic Canadian zone. The nonlinear analyses of CSWs under earthquake records are conducted in two steps. At first, the nonlinear time-history analyses of two types of CSWs are carried out using RUAUMOKO program and the deficiencies of old-designed CSW are identified through the comparison of obtained results. In the second step, the old design CSW is retrofitted using CFRP sheets and reanalysed to investigate the benefits of the retrofit technique in mitigating the shortcomings. The results indicate that CFRP retrofitting is an efficient method to enhance the seismic performance of deficient old CSWs in terms of story displacement, inter-story drift, CBs rotation, and ductility demand.

关键词： Coupled shear wall coupling beam CFRP retrofit method non-linear time history analysis old code new code

来源：评论

学校读者我要写书评

暂无评论

Experimental Seismic Performance Evaluation of Coupling Beams: Comparison of old with Modern codes

引用

JOURNAL OF EARTHQUAKE ENGINEERING 2021年第11期25卷 2269-2284页

作者： Honarparast, Sara Chaallal, Omar Univ Quebec Ecole Technol Super Dept Construct Engn Montreal PQ H3C 1K3 Canada

This study presents the results of an experimental investigation on the seismic performance of two reinforced concrete coupling beams (CBs) for coupled shear walls, one with a conventional reinforcement layout designed according to the old National Building code of Canada (NBCC) 1941 and the other one with a diagonal reinforcement configuration designed according to modern NBCC 2015 and Canadian Standard Association (CSA) A23.3 2014 requirements. Experimental tests were conducted to investigate the behavior of specimens under reversed cyclic loading. The experimental results reveal that the diagonal reinforcement configuration could increase the load-resisting capacity and energy dissipation capacity by 4.4 and 10.2 times, respectively. Moreover, the maximum rate of stiffness degradation decreased from 96% in conventionally reinforced CB to 57% in diagonally reinforced CBs. Furthermore, diagonal reinforcement layout led to more stable hysteretic behavior without considerable pinching. In contrast and as expected, the conventionally reinforced CB did not comply with the requirements of the new design code. Therefore, such CBs should be retrofitted to upgrade their seismic performance in conformity with updated standards requirements.

关键词： Reinforced concrete coupled shear wall coupling beam seismic performance cyclic loading test old code modern code

来源：评论

学校读者我要写书评

暂无评论

Non-linear time history analysis of reinforced concrete coupled shear walls: Comparison of old design, modern design and retrofitted with externally bonded CFRP composites

引用

ENGINEERING STRUCTURES 2019年 185卷 353-365页

作者： Honarparast, Sara Chaallal, Omar Univ Quebec Ecole Technol Super Dept Construct Engn Montreal PQ H3C 1K3 Canada

When appropriately designed, coupled shear walls (CSWs) are very effective lateral load resisting systems for medium to high rise buildings. They reduce the deformation demands on the building and distribute the inelastic deformation between the coupling beams (CBs) and the wall piers. Their seismic performance depends mainly on the ability of their CBs to provide adequate stiffness and strength. Therefore, the design of the CBs and the walls at their base is of paramount importance. However, many existing buildings with CSWs feature unsatisfactory behaviour under lateral loading as they were designed and constructed according to old codes and standards with insufficient requirements for seismic design. Their seismic retrofit is therefore inevitable. Many conventional retrofit techniques have been attempted in the past to improve the seismic behavior of CSWs. Recently, an innovative technique using externally bonded fibre reinforced polymer (EB-FRP) composite to strengthen existing reinforced concrete (RC) structural elements has emerged. The current study focuses on two objectives related to CSWs: (i) evaluate the seismic performance of old designed CSWs and highlight their deficiencies by comparing its response with that of corresponding modern design CSWs;and (ii) evaluate the effectiveness of EB-Carbon FRP (EB-CFRP) retrofitting on the seismic response of deficient CSWs. To achieve these objectives, two 20-story CSWs located in Western seismic Canadian zone were considered. One CSW was designed according to old National Building code of Canada (NBCC) 1941 and the other one designed in conformity with modern NBCC 2015 and Canadian Standard Association (CSA) A23.3-14. The nonlinear time-history analyses of the two types of CSWs as well as the CFRP retrofitted one under simulated earthquake motions are carried out using RUAUMOKO program. The observed results confirmed the effectiveness of CFRP retrofitting in enhancing the seismic performance of deficient old CSWs

关键词： Reinforced concrete coupled shear wall Coupling beam Non-linear time history analysis CFRP retrofit method Seismic performance old code Modern code

来源：评论

学校读者我要写书评

暂无评论

Collapse Time of Reinforced Concrete Buildings with Brittle Columns

引用

JOURNAL OF ASIAN ARCHITECTURE AND BUILDING ENGINEERING 2018年第3期17卷 495-502页

作者： Nakamura, Takaya Yoshimura, Manabu Niigata Univ Architecture Program Niigata Japan Tokyo Metropolitan Univ Dept Architecture & Bldg Engn Tokyo Japan

Buildings with brittle columns an in danger of gravity load collapse and may be hazardous in the event of future earthquakes. To plan for building evacuation, the time required for such buildings to collapse must be known. This study thus uses dynamic analysis to examine the collapse time of reinforced-concrete (RC) buildings designed according to old Japanese codes. Model lateral load vs interstory drift relations are represented based on previous collapse tests of brittle columns. The results reveal that (1) in most cases, the time between shear failure and collapse is very short for individuals to safely evacuate a building, and (2) the collapse time can be long for earthquakes with long durations.

关键词： reinforced concrete collapse time old code shear failure

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：