Download or read book Use of Flexible and Ductile Roof Diaphragms in the Seismic Design of Single storey Steel Buildings written by Kishor Mohan Shrestha and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis documents an investigation of the use of the roof diaphragm flexibility in the seismic design and analysis procedure of single-storey steel buildings designed otherwise in accordance with the provisions of the 2010 NBCC and the 2009 CSA S16. The design approach considers the members of the vertical bracing system as the ductile fuse elements in the seismic force resisting system (SFRS), whereas the diaphragm remains elastic. An alternative design approach was also examined in which the steel deck roof diaphragm acts as a ductile fuse element in the SFRS; at present this procedure is not permitted by the NBCC or CSA S16. The investigation was reliant on a complementary three phase test program in which nineteen large-scale roof diaphragm specimens were dynamically excited with a sequence of increasing amplitude loading protocols. The first part of the study comprised the development of a deep horizontal plane truss numerical model using the OpenSees ...
Download or read book Behaviour of Steel Structures in Seismic Areas written by Federico Mazzolani and published by CRC Press. This book was released on 2009-12-03 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt: Behaviour of Steel Structures in Seismic Areas comprises the latest progress in both theoretical and experimental research on the behaviour of steel structures in seismic areas. The book presents the most recent trends in the field of steel structures in seismic areas, with particular reference to the utilisation of multi-level performance bas
Download or read book Seismic Design for Buildings written by United States. Department of Defense. Tri-Service Seismic Design Committee and published by . This book was released on 1973 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fourth International Conference on Advances in Steel Structures written by Z Y Shen and published by Elsevier. This book was released on 2005-06-07 with total page 963 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two volume proceedings contains 11 invited keynote papers, 33 invited papers, and 225 contributed papers presented at the Fourth International Conference on Advances in Steel Structures (ICASS '05) held on 13-15 June 2005 in Shanghai, China. ICASS provides a forum for discussion and dissemination by researchers and designers of recent advances in the analysis, behaviour, design and construction of steel structures. Contributions to the papers came from 22 countries around the world and cover a wide spectrum of topics including: Constructional Steel, Hybrid Structures, Nonferrous Metals, Analysis of Beams and Columns, Computations, Frames, Design, Space Structures, Fabrication, along with a variety of other key subjects presented at the conference.
Download or read book Dynamic Behaviour and Inelastic Performance of Steel Roof Deck Diaphragms written by Robert Massarelli and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidelines for Seismic Evaluation and Rehabilitation of Tilt up Buildings and Other Rigid Wall flexible Diaphragm Structures written by and published by . This book was released on 2001 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Design Repair and Retrofit Strategies for Steel Roof Deck Diaphragms written by John-Edward Franquet and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Design for Buildings written by and published by . This book was released on 1982 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Analysis and Design of Rigid Wall Flexible Roof Diaphragm Buildings written by Maria Koliou and published by . This book was released on 2014 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, the seismic response and design of Rigid Wall-Flexible Roof Diaphragm (RWFD) buildings under extreme ground shaking was investigated. RWFD buildings are a type of low-rise industrial construction widely used in North America that incorporates rigid in-plane concrete or masonry walls and flexible in-plane wood, steel or "hybrid" roof diaphragms. This type of structure has exhibited poor seismic response during past earthquake events, where the global system response was dominated by the response of the roof diaphragm. This is mainly attributed to large diaphragm displacements, which can significantly exceed the displacements of in-plane walls. A two-dimensional (2D) simplified numerical framework of RWFD buildings was developed to investigate the seismic performance of this type of structure and validate current and proposed design approaches. The modeling approach is detailed enough to capture the nonlinear response of RWFD buildings, and simplified enough to efficiently conduct a large number of nonlinear time-history dynamic analyses. The 2D numerical framework is based on a three step sub-structuring approach including: (1) hysteretic response database for diaphragm connectors, (2) 2D inelastic diaphragm model incorporating hysteretic connector response and (3) 2D building model incorporating hysteretic diaphragm model response. This numerical framework was validated using experimental and analytical data available in the literature. A case study investigating the out-of-plane wall anchorage forces for a typical RWFD building archetype was performed in this dissertation. The main objectives of this case study were to: (i) evaluate the out-of-plane wall anchorage force distribution along the roof span, (ii) evaluate the influence of wall-to-roof diaphragm connection stiffness on the magnitude of the out-of-plane wall anchorage forces, and (iii) evaluate the correlation between the in-plane shear forces in the roof diaphragm and the out-of-plane wall anchorage forces. The seismic collapse capacity of RWFD buildings designed to current code provisions in the United States was evaluated by applying the FEMA P695 methodology for a large set of representative archetype buildings. This study showed that certain "weak" aspects of the code provisions referring to the seismic response of RWFD buildings and the underestimation of their fundamental period of vibration. Two fundamental period formulas (a rigorous mechanics based period formula and a semi-empirical period formula) were recommended to address the underestimation of the fundamental period. The concept of distributed yielding in the flexible roof diaphragm by weakening certain intermediate diaphragm zones was explored as a cost effective means to improve the seismic collapse capacity of RWFD buildings and mitigate their seismic vulnerability. The efficiency of the proposed concept was numerically investigated in this dissertation for two case study RWFD buildings incorporating a steel and a hybrid flexible roof diaphragm, respectively. This dissertation concluded by proposing a new rational seismic design approach for RWFD buildings based on the concept of distributed roof diaphragm yielding. This approach relies on forcing yielding of the roof diaphragm as the predominant inelastic response under extreme ground shaking instead of the vertical elements of the seismic force-resisting system (SFRS). In a force-based design framework, a response modification factor (R) for the roof diaphragm is recommended to be used along with the R-factor for the vertical elements of the SFRS as currently used in seismic design codes. Moreover, the proposed design approach includes stronger end diaphragm regions, to spread yielding deeper into the roof diaphragm, by introducing an overstrength factor increasing the design shear forces for the diaphragm boundaries. The proposed design approach was validated through the FEMA P695 methodology for a large set of building archetypes.
Download or read book The Effects of Diaphragm Flexibility on the Seismic Response of One Storey Steel Buildings written by Pedram Mortazavi and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Development of Seismic Design Forces for Flexible Floor Diaphragms in Reinforced Concrete Wall Buildings written by Jorge Alberto Rivera and published by . This book was released on 2009 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Civil Engineering written by and published by . This book was released on 1999 with total page 968 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Response of Low Rise Masonry Buildings With Flexible Roof Diaphragms written by Gregory L. Cohen and published by . This book was released on 2001 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study compares the responses from shaking-table testing and analytical predictions evaluated in the context of geometric scaling, to provide a coherent description of the seismic response of low-rise masonry buildings with flexible roof diaphragms. Two half-scale, low-rise reinforced masonry buildings with flexible roof diaphragms are subjected to carefully selected earthquake ground motion on the Tri-axial Earthquake and Shock Simulator at the Construction Engineering Research Laboratory. Damage to the half-scale specimens is assessed using published protocols. Geometric scaling analysis relates response and damage of the half-scale specimens to those of the full-scale prototype structures. Linear elastic modeling is simplified to a generalized two-degrees-of-freedom idealization. Response-spectrum analysis of such an idealization is accurate and justified for prediction of dynamic response of the half-scale specimens and the corresponding full-scale prototype. It is shown that low-rise masonry buildings with flexible roof diaphragms can be designed for seismic loads as single-degree-of- freedom systems, using the degree of freedom associated with the in-plane response of the diaphragm in the building's transverse direction, rather than the degree of freedom associated with the in-plane responses of the shear walls.
Download or read book Analytical Study to Investigate the Seismic Performance of Single Story Tilt up Structures written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes an analytical study to investigate the seismic performance of single-story tilt-up structures with steel deck roof diaphragms. A review of current practice in North America for the seismic design of tilt-up structures reveals two points of interest; the flexibility of the roof diaphragm is not considered in calculation of the fundamental building period for the design, and that a force-based approach is used for seismic design that does not incorporate the principles of capacity-design currently used in other building systems, such as moment frames, braced frames, and shear walls. To explore the application of capacity design for tilt-up structures, three possible failure mechanisms are investigated and compared: rocking of wall panels, sliding of wall panels, and frame action for buildings with wall panels incorporating large openings. Based on results of an industry survey, two building archetypes are created to represent the most common building types found in seismically active areas; one including solid panels and the second incorporating panels with large openings. Consideration of the sliding mechanism suggests it would be difficult to incorporate into common applications due to building geometry irregularities, difficulties in estimating sliding resistance, and permanent deformation resulting from the mechanism. Analytical results from this study are compared with findings from previous research; the most interesting comparison showed the period from the analytical model to be within 10% of the estimated building period from ASCE 41 when the weight of the out-of-plane walls are considered in the estimate. The rocking mechanism and frame mechanism are studied further by carrying out a preliminary assessment of seismic performance factors (R-values) utilizing concepts from the ATC-63 Methodology. Various analyses, including non-linear time history analyses for a suite of earthquakes, are carried out on 3D models of the building archetypes.
Download or read book Examination of Lateral Stiffness and Strength of Pitched Residential Roof Diaphragms with Implications for Seismic Design written by William J. Kirkham and published by . This book was released on 2013 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are about 80 million single-family dwellings (SFD) in the United States, predominantly of wood-frame construction. Of these, 68% are owner occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all SFD in America, 50% were built before 1974, and 76% built before 1990. Most wood frame SFD (WFSFD) were built to prescriptive code provisions before seismic requirements were introduced. This dissertation examines a broad field of seismic research applicable to WFSFD seismic analysis and the design, and to the retrofit of existing WFSFD. It summarizes the "state-of-the-art" of seismic experimentation and seismic evaluation, and provides observations and recommendations for future research. The study showed that performance based design (PBD) needs to develop a consensus on performance objectives for WDSFD with respect to damage and repair costs, including new design techniques which balance life-safety with the effects of damage to building finish materials. There is also a strong need to develop a better understanding of the effects of WDSFD components, attachment, the lateral force resisting system and how loads are distributed to these elements within the structure. To address concerns with limited pitched light-frame roof diaphragm experiments, ten full size (3.7 x 4.9 m) plywood roof diaphragms with metal plate connected (MPC) common and hip wood trusses or joists, typical of WFSFD construction were tested according to ASTM E455. Specimens included three gable roof slopes of 33, 67 and 100%, a hip roof of 33% slope, and a flat roof. Gable and hip roofs experiments examined the effect of eave sheathing and gypsum ceilings on the bottom chord. Results showed eave plywood had negligible effect on diaphragm apparent stiffness; gable roofs had apparent stiffnesses that were about 50% that of the flat roofs; and gypsum provided more than 1/3 of the total roof apparent stiffness for gable roofs at slopes of less than 33%. There was no effect of pitch on ultimate roof strength in any configuration and all exhibited approximately the same ultimate shear strength. Failure modes of roofs included nail withdrawal, nail tear-through, metal plate tear-out on trusses and chord tensile failure. This dissertation also examines code provisions applicable to WFSFD seismic design, compares rigid and flexible diaphragm analyses for different geometries of "L" shaped WFSFD applying stiffness reductions due to differing roof geometry and pitch. These analyses are applied to historic earthquake damage reports and compared with a practical rigid, semi-rigid or flexible diaphragm plate FEM analysis method. This study determined that most WFSFD should be designed using an envelope method due to a mix of diaphragm types and the effects of roof pitch and geometry on the stiffness. Cases may occur where determination of semi-rigid or flexible diaphragm behavior is difficult because the code prescribed analysis is contradictory or fallacious. This suggests that use of semi-rigid finite element model (FEM) or a manual envelope method is prudent. The use of RP, FP or SP FEM methods can be simple and practical methods for analyzing WFSFD with a reasonable level of detail and effort.
Download or read book Seismic Design of Rigid Wall flexible Diaphragm Buildings written by Building Seismic Safety Council (U.S.) and published by . This book was released on 2015 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NEHRP Recommended Provisions National Earthquake Hazards Reduction Program for Seismic Regulations for New Buildings and Other Structures Commentary written by United States. Federal Emergency Management Agency and published by . This book was released on 2001 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
