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SEISMIC BEHAVIOR ASSESSMENT OF LOW-RISE REINFORCED CONCRETE STRUCTURAL WALLS USING QUASI-STATIC REVERSED CYCLIC LOADING PROTOCOL A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF NATURAL AND APPLIED SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY POURANG EZZATFAR PhD, Department of Civil Engineering Supervisor: Prof. Dr. Erdem Canbay Co-Supervisor: Prof. Dr. Güney Özcebe June 2016, 194 Pages The reinforced concrete shear walls of low- to mid-rise residential buildings, having height to length ratio ranging from 1 to 3, are more of a concern in research studies in recent years. Since the failure mode of these walls depends on the interaction between shear and flexural action, predicting the failure mode of this type of shear walls is not straight forward. While seismic behavior of highrise walls (i.e. aspect ratio greater than about 3) is almost known and theoretical assumptions matches well with experimental findings, experimental and theoretical studies are still demanding to better understand the seismic behavior, failure modes, lateral load bearing and deformation capacities of low- to mid-rise RC shear walls. Most of the available experimental studies within the relevant literature were done on isolated cantilever RC walls in laboratories. However, simulating the effect of earthquake loads on large scale RC shear walls surrounded by frame elements is very rare. In order to investigate the seismic performance of the RC shear walls in conjunction with other structural elements as a system in low- to mid-rise buildings, two ½ scaled three-story three-bay RC test frames with RC shear wall in middle bay were tested. One of the specimens was designed to Turkish earthquake code (TEC-2007) and Turkish reinforced concrete practice code (TS500-2000) and the other was designed according to TEC-1975 and TS500- 1981. Modeling parameters and acceptance criteria for nonlinear analysis given by ASCE/SEI41-13 and TEC-2007 for the investigated RC shear wall specimens were assessed. Keywords: reinforced concrete shear walls, large scale experimental testing, seismic behavior, performance evaluation دانلود منبع PEZ.pdf

Seismic Behavior of Direct Displacement-based Designed Eccentrically Braced Frames A. Mohebkhah* , S. Farahani Department of Civil Engineering Faculty of Civil and Architectural Engineering, Malayer University, Malayer, Iran Direct Displacement-Based Design (DDBD) is a performance-based seismic design method that has been proposed and well developed over the past two decades to design RC frame structures, shear walls and bridges. In this method, an equivalent single-degree-of-freedom (SDOF) substitute structure is utilized to estimate seismic displacement demands of a multi-degree-of-freedom (MDOF) system. Although this method has been used to design the above mentioned structures, however, there is just one comprehensive DDBD method to design steel eccentrically braced frames (EBFs) in the literature. The purpose of this study is to investigate nonlinear seismic behavior of the DDB designed EBFs with short, intermediate and long link beams and estimate their seismic demands. To this end, twelve 3, 5, 9 and 12-story EBFs were designed using the proposed DDBD method. To simulate the nonlinear cyclic behavior of link beams, a macro-model proposed in the literature was adopted and validated with the available tests results. In order to describe material nonlinearity of the framing members in the macromodel, distributed plasticity fiber based model was used. After validating the FEM macro-modeling technique of link beams, seismic behavior of the 2D EBFs was investigated with nonlinear time-history analysis under a set of selected earthquake records using the structural analysis software OpenSees (ver. 2.4.0). The results showed that the DDB designed EBFs generally can reach their anticipated performance level. دانلود DDB Designed EBFs.pdf

EVALUATION OF DIRECT-DISPLACEMENT BASED SEISMIC DESIGN METHOD FOR EBFs Amin MOHEBKHAH Assistant Professor of Structural Eng., Dept. of Civil Eng., Malayer University, Malayer, Iran amoheb@malayeru.ac.ir Sina FARAHANI M.Sc. Student of Structural Engineering, Dept. of Civil Eng., Malayer University, Malayer, Iran sina_farahani459@yahoo.com, sina.farahani@stu.malayeru.ac.ir Keywords: Direct displacement-based design, Steel eccentrically braced frame, Seismic behavior, Nonlinear dynamic analysis, Performance level Recent research in the field of earthquake engineering has seen the development of number of different displacementbased seismic design (DBD) methods. Such methods aim to overcome limitations with the force-based design methods incorporated in current codes. The most developed DBD method currently available is the Direct DBD approach, described and investigated in a text by Priestley et al. (2007). While the guidelines in the DDBD code have been relatively well tasted for RC structures, further verification and development is required for steel frame systems. There is just one comprehensive study can be found on DDBD of eccentrically braced frames (EBFs) which has been published recently by Sullivan (2013). The study presented by Sullivan (2013), has been focused of DDBD of EBFs with short (shear) link beams. Therefore, the aim of present study is to evaluate the ability of DDBD method for designing EBFs with intermediate and long link beams. To this end, three five-storey EBFs with short, intermediate and long link beams designed using the DDBD method proposed by Sullivan (2013). Figure 1 shows the case study EBF structures selected for examination in this paper. دانلود منبع 00390-SD.pdf

EVALUATION OF SEISMIC BEHAVIOR OF IRREGULAR TUBE BUILDINGS IN TUBE SYSTEMS ABSTRACT: Setbacks in the volume of a building usually arise from the demands of urban design for illumination, proportion, etc. However, in seismic events they are the cause of abrupt changes in stiffness and mass producing a concentration of stresses in the floors near the site of sudden change. In general terms, one should ensure that the transitions are as gradual as possible in order to avoid such concentration of stresses. This study is intended to investigate seismic behavior of irregular building tube in tube systems, for this purpose seismic behavior of 40-story and 60-story reinforced concrete frame building with irregular plan was evaluated, seismic behavior of irregular buildings was assessed by overall building drifts, story drifts and shear lag behavior factors.. Higher irregularities in the overall plan structure of a building increase the phenomena of story drift and shear lag phenomena. Story drift and shear lag are higher for 60-story building than for a 40-story building. منبع دانلود EVALUATION OF SEISMIC.pdf

Seismic behavior of code designed steel plate shear walls Jeffrey W. Berman∗ Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195-2700, United States Engineering Structures 33 (2011) 230–244 AbstractThe AISC Seismic Design Provisions now include capacity design requirements for steel plate shear walls, which consist of thin web plates that infill frames of steel beams, denoted horizontal boundary elements (HBEs), and columns, denoted vertical boundary elements (VBEs). The thin unstiffened web plates are expected to buckle in shear at low load levels and develop tension field action, providing ductility and energy dissipation through tension yielding of the web plate. HBEs are designed for stiffness and strength requirements and are expected to anchor the tension field formation in the web plates. VBEs are designed for yielding of web plates and plastic hinge formation at the ends of the HBEs. This paper assesses the behavior of code designed SPSWs. A series of walls are designed and their behavior is evaluated using nonlinear response history analysis for ground motions representing different hazard levels. It is found that designs meeting current code requirements satisfy maximum interstory drift requirements considering design level earthquakes and have maximum interstory drifts of less than 5% for maximum considered earthquakes. Web plate ductility demands are found to be significantly larger for low rise walls than for high rise walls where higher modes of vibrations impact the response. The percentage of story shear resisted by the web plate relative to the boundary frame is found to be between 60% and 80% and is relatively independent of panel aspect ratio, wall height, or hazard level, but is affected by transitions in plate thickness. Maximum demands in VBEs in design level shaking are found to be considerably less than those found from capacity design for SPSWs with 9 or more stories. Research highlights► Steel plate shear walls designed via current building code requirements meet drift limitations. ► Web plate ductility demands in low-rise steel plate shear walls are significantly larger than those in taller steel plate shear walls. ► The percentage of story shear resisted by the web plates was found to range from 60–80% and is independent of aspect ratio, wall height and seismic demand but is affected by transitions in web plate thickness. ► Maximum demands in steel plate shear wall columns from nonlinear response history analysis are found to be considerably less than those determined from capacity design in steel plate shear walls with 9 or more stories. Keywords Steel plate shear walls; Seismic behavior; Ductility; Seismic design; Column demands; Steel structures; Shear walls 10.1016_J.ENGSTRUCT.2010.10.015-Seismic-behavior-of-code-designed-steel-plate-shear-walls.pdf

Seismic Behavior Assessment of The Historical Tomb of Sheikh Shahab-edin Ahary Original Article, D58 Pouraminian M, Pourbakhshian S, Khodayari R. J. Civil Eng. Urban. 4(4): 382-389. 2014 ABSTRACT: This study aims to investigate failure mechanism of historical tomb of Shahab-edin Ahary elements and determines areas prone to structural failure. Since Ahar is one of the most earthquake-prone cities of Iran with relative risk of large earthquakes, the presence of multiple faults in this area as well as historical, cultural and tourism importance of the building, makes its vulnerability assessments and retrofitting inevitable. Because of low adhesion strength of masonry used in the building and regarding its vulnerability records on previous earthquakes, the building seems weak against relatively intense earthquakes. The aim of this study is to investigate vulnerability of this building against possible earthquakes. Selected earthquakes for seismic loading are modified for the maximum horizontal acceleration obtained for this region. Various results have been studied after utilize finite element model using Ansys software and various analyses. Keywords: Seismic Behavior, Historical Buildings, Dynamic Analysis, Sheikh Shahab-Edin Ahary, Macro Modeling. منبع: [Hidden Content] دانلود: [Hidden Content].,%204%20(4)%20382-389,%202014.pdf J. Civil Eng. Urban., 4 (4) 382-389, 2014.pdf

Toward buckling free tension-only braces using slack free connections Seyed Amin Mousavi a, Seyed Mehdi Zahrai a,⁎, Murat Saatcioglu b a School of Civil Engineering, College of Engineering, The University of Tehran, P.O. Box 11155-4563, Tehran, Iran b Department of Civil Engineering, The University of Ottawa, Ottawa KIN 6N5, Canada a r t i c l e i n f o a b s t r a c t Article history: Received 15 July 2014 Received in revised form 25 August 2015 Accepted 28 August 2015 Available online xxxx Keywords: Tension-only brace Buckling free Hysteretic behavior Energy dissipation Seismic behavior Slack free connection This study introduces a slack free connection (SFC) by which pinchingwould be removed fromhysteretic behavior of tension-only braces (TOBs). SFC through its mono-directional behavior, eliminates undesirable pinching of the tension-only bracing and changes it to a reliable lateral load resisting system with high energy dissipation capability. A Matlab/Simulink-based model, called Macro-Simulink model, is developed to simulate hysteretic behavior of TOBs with orwithout SFC. Derived Macro-Simulink model is also able to account for hysteretic behavior of the frame. The frame itself can have either deteriorated or non-deteriorated hysteretic behaviors. The Macro- Simulink model is verified through different techniques including earlier experimental results, explicit finite element modeling, and other pre-verified analytical/numerical tools. It is observed that initial pre-tension load only affects initial stiffness of the TOB and has no contribution on its nonlinear hysteretic behavior. Obtained results of this study indicate that energy dissipation capacity of TOBs with SFC would be improved up to 6 times compared with that of conventional TOBs. Moreover contribution of SFC is more pronounced in the case of frames with highly deteriorated behaviors. As a result TOB with SFC can be considered for retrofit purposes as well. منبع [Hidden Content] دانلود: [Hidden Content] EoGZ7fgV.pdf