جستجو در تالارهای گفتگو

Influence of Aspect Ratio & Plan Configurations on Seismic Performance of Multistoreyed Regular R.C.C. Buildings: An Evaluation by Response Spectrum Analysis Sanjay Kumar Sadh 1, Dr. Umesh Pendharkar 2 1 M.E.(CASDD) Student, Civil Engineering Department, U.E.C. Ujjain, M.P., INDIA 2 Professor Civil Engineering Department, U.E.C. Ujjain, M.P., INDIA Abstract - The behavior of a building during earthquakes depends critically on its overall shape, size and geometry. Earthquake resistant design of buildings depends upon providing the building with strength, stiffness and inelastic deformation capacity which are great enough to withstand a given level of earthquakegenerated force. This is generally accomplished through the selection of an appropriate building configuration and the careful detailing of structural members. Configuration is critical to good seismic performance of buildings. The important aspects affecting seismic configuration of buildings are overall geometry, structural systems, and load paths. The building slenderness ratio and the building core size are the key drivers for the efficient structural design. This paper focuses on the effect of both Vertical Aspect Ratio (H/B ratio i.e. Slenderness Ratio) and Horizontal or Plan Aspect Ratio (L/B ratio), where H is the total Height of the building frame, B is the Base width and L is the Length of the building frame with different Plan Configurations on the Seismic Analysis of Multistoried Regular R.C.C. Buildings. The test structures are kept regular in elevation and in plan .Here, height and the base dimension of the buildings are varied according to the Aspect Ratios. The values of Aspect Ratios are so assigned that it provides different configurations for Low, Medium and High-rise building models. In the present study, four building models having different Horizontal Aspect ratios viz. 1, 4, 6 & 8 ranging from 12m.to 96m.length of different Vertical Aspect ratios (slenderness ratios) viz. 1, 4, 6 & 8 of varying 4, 16, 24 & 32 storeys have been considered and their influence on the behavior of the RCC Multistoreyed buildings is demonstrated, using the parameters for the design as per the IS-1893- 2002-Part-1 for the seismic zone- 3. In this way total 16 building models are analyzed for different load combinations by Linear Elastic Dynamic Analysis (Response Spectrum analysis) with the help of ETABS-2015 software and the results obtained on seismic response of buildings have been summarized. دانلود IRJET-V3I150.pdf

Seismic Performance of Steel Plate Shear Walls Considering Various Design Approaches 14-0005 R. Purba and M. Bruneau MCEER-14-0005 | 10/31/2014 | 562 pages Keywords: In-span plastic hinge; Experimental; Steel plate shear walls; Seismic performance; Deterioration and failure modes; Deterioration model; Collapse potential; Collapse fragility curve; Seismic Performance Factors; Infill plate design; FEMA P695 Methodology Abstract: This report presents the results of experimental and analytical studies to investigate the seismic performance of steel plate shear walls (SPSWs) considering different design philosophies of horizontal boundary elements (HBEs) and infill plates. The experimental study on a three-story SPSW specimen showed the development of HBE in-span hinges which resulted in an accumulation of plastic incremental deformations. A finite element investigation on the tested SPSW specimen demonstrated similar behavior. Furthermore, collapse assessment of SPSWs with various structural configurations (e.g., panel aspect ratio, seismic weight intensity, and number of stories) was conducted to investigate impact of sharing of story shear forces between the boundary frames and infill plates on the performance of SPSWs. SPSWs designed with the current seismic performance factors specified in the ASCE 7-10 and neglecting the contribution of their boundary moment resisting frames to resist story shear forces met the FEMA P695 performance criterion, while that was not the case for SPSWs designed considering the sharing of story shear forces between the boundary frame and infill plates. Adjusted seismic performance factors were required for the latter SPSWs to rigorously meet the FEMA P695 performance criteria. Most importantly, the latter SPSWs were found to have a higher probability to suffer significantly larger interstory drift than the former. This research extends work reported in “Impact of Horizontal Boundary Elements Design on Seismic Behavior of Steel Plate Shear Walls” by R. Purba and M. Bruneau, MCEER-10-0007. The finite element analysis was performed using the software ABAQUS/Standard while the collapse assessment was performed using the software OpenSees. منبع دانلود Seismic_Performance_of_Steel_Plate.pdf

Seismic performance comparison of thin steel shear wall and cross brace by Non-linear static analysis Pooria MOSHAVER Department of Civil Engineering, Engineering Faculty, College of Technical and Vocational University Sanandaj Branch, Sanandaj, Iran. Abstract. Steel shear wall system has been rapidly paid into attention as a resistant system against lateral loads within 3 recent decades. This system also is used for construction and retrofitting of important buildings entire the world particularly in seismicity countries such as Japan and the US. In addition, during the recent years, seismic design of the structures through changing design criterion from resistant methods to performance has been considerably welcomed by engineering society. For evaluation of constructed structures based on prior regulations, structures design regulations (regulation 2800) cannot be used and such instructions as instruction for seismic rehabilitation should be employed which evaluate and rehabilitate the structures using performance-based design concept. In present study, general performance parametric assessment of Intermediate Steel Moment Frame was carried out along with evaluation of thin Steel Shear Wall (SSW) and convergent cross brace. For this purpose, several steel frames were modeled using SAP 2000 software package. Performance assessment of each frame was conducted using non-linear static analysis or Push Over and performance point of each frame was specified using the concepts capacity spectrum and demand spectrum. 5000127326-5000205434-1-PB.pdf

Performance of industrial facilities and lifelines during the October 23rd, 2011 Van, Turkey Earthquake Kiarash Nasserasadi; Mehran Seyed Razzaghi Damage to essential facilities (e.g. lifelines and industrial facilities) due to extreme loads may cause remarkable indirect impact as well as direct physical loss. Hence understanding seismic performance of essential facilities is very important in high seismic risk regions. On October 23, 2011 an earthquake of magnitude Mw7.2 occurred in Van province in eastern Turkey. Several damages occurred at industrial plants. Damage to equipment and buildings caused work abandon in some industrial plants. In this paper the observed damage to essential facilities such as transportation systems, silos and gas stations are presented. منبع دانلود JSEG451443558600.pdf

Seismic Performance of Steel Plate Shear Walls Using Nonlinear Static AnalysisDHAR, MOON MOON (2015) Seismic Performance of Steel Plate Shear Walls Using Nonlinear Static Analysis. Masters thesis, Concordia University. AbstractUnstiffened steel plate shear wall (SPSW) is considered as a primary lateral load resisting system due to its significant post-buckling strength, high ductility, stable hysteretic behaviors and robust initial stiffness. Nonlinear seismic analysis can accurately estimate structural responses, however, the method is very time consuming and may not be suitable for regular engineering practice. On the other hand, traditional pushover analysis method does not consider contributions of higher modes to the structural responses and thus, often do not provide good estimation of seismic responses for taller buildings. Capacity-Spectrum Method (CSM) and modal pushover analysis (MPA) are two simple nonlinear static methods that have been proposed and recently used for seismic performance evaluation of few lateral load-resisting systems. This research further examines the applicability of CSM and MPA methods to assess seismic performance of steel plate shear walls. A nonlinear finite element model was developed and validated with experimental studies. Three different SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed by subjecting the steel shear walls under artificial and real ground motions for Vancouver. The CSM and MPA procedures were applied to analyse the selected SPSWs and the results were compared with more accurate nonlinear seismic analysis results. It is observed that both CSM and MPA procedures can reasonably predict the peak roof displacements for low-rise SPSW buildings. In addition, MPA procedure, which includes contributions of higher modes when estimating seismic demands of buildings, provides better predictions of critical seismic response parameters for taller SPSWs. منبع: [Hidden Content] دانلود: [Hidden Content]1/Dhar_MASc_S2015.pdf Dhar_MASc_S2015.pdf

Design and seismic response of modified suspended zipper braced frames Haifeng Yu ⁎, Yaran Guo, Yan Zhang, Xin Wang Hebei University of Science and Technology, Shijiazhuang 050018, China a b s t r a c t In a conventional suspended zipper braced frame (SZBF), the required strength of zipper columns and top story braces increases rapidly with the number of stories, resulting in unacceptable cross sections for these members. To overcome these drawbacks, a new modified suspended zipper braced frame (RZBF) is proposed in this paper. Compared with SZBF, the two central ideas of RZBF are that the unbalanced vertical forces at each story do not reach the maximum values simultaneously, and that the braced beams can transfer part of the unbalanced vertical forces during earthquakes. In order to understand better the seismic performance and design advantages of RZBF, nonlinear time history analyses were conducted on 3, 6, 10, 15, and 18-story RZBF and SZBF models. Comparison of the results obtained demonstrates the efficiency and viability of RZBF. Moreover, it is shown that the RZBF saves more steel material as the number of stories increases. © 2015 Elsevier Ltd. All rights reserved. Keywords: Braced frame Seismic design Zipper column Nonlinear time history analysis Seismic performance 10.1016_j.jcsr.2015.12.025-Design-and-seismic-response-of-modified-suspended-zipper-braced-frames.pdf

Study on Seismic Performance of a Stiffened Steel Plate Shear Wall with Slits Jin-yu Lu,1,2 Lu-nan Yan,1,2 Yi Tang,1,2 and Heng-huaWang1,2 1Key Lab of Concrete and Prestressed Concrete Structures of Ministry of Education, Nanjing 210096, China 2School of Civil Engineering, Southeast University, Nanjing 210096, China Correspondence should be addressed to Jin-yu Lu; davidjingyu@gmail.com Received 8 June 2015; Revised 4 August 2015; Accepted 16 August 2015 Academic Editor: Giorgio Dalpiaz Copyright © 2015 Jin-yu Lu et al.This is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. To determine the force mechanism for the steel plate shear wall with slits, the pushover analysis method was used in this study. An estimated equation for the lateral bearing capacity which considered the effect of edge stiffener was proposed. A simplified elastic-plastic analytical model for the stiffened steel slit wall composed of beam elements was presented, where the effects of edge stiffeners were taken into account. The wall-frame analysis model was established, and the geometric parameters were defined. Pushover analysis of two specimens was carried out, and the analysis was validated by comparing the results from the experiment, the shell element model, and a simplified model.The simplified model provided a good prediction of the lateral stiffness and the strength of the steel slit wall, with less than 10%error compared with the experimental results.Themutual effects of the bearing wall and the frame were also predicted correctly. In the end, the seismic performance evaluation of a steel slit wall-frame structure was presented. The results showed that the steel slit wall could prevent the beams and columns from being damaged by an earthquake and that the steel slit wall was an efficient energy dissipation component. downloads.hindawi.com/journals/sv/aa/689373.pdf 689373.pdf