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 Minimum Design Loads for Buildings and Other Structures written by American Society of Civil Engineers and published by Amer Society of Civil Engineers. This book was released on 2000 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Engineering Handbook written by Edwin Henry Gaylord and published by McGraw-Hill Companies. This book was released on 1990 with total page 1242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sixth brilliant book from Andy McDermott-Clive Cussler's heir apparent-featuring archaeologist Nina Wilde and ex-SAS member Eddie Chase.
Download or read book Lateral Tests on Full Scale Lumber and Plywood Sheathed Roof Diaphragms written by Stillinger, JR. and published by . This book was released on 1955 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: During 1952 and 1953, the Timber Mechanics Section of the Oregon Forest Products Laboratory built and tested eight lumber-sheathed and two plywood-sheathed roof diaphragms 20 by 60-ft in size, in order to determine the strength and stiffness at various load levels when the following structural elements were investigated: (1) 3/8 -in. plywood sheathing; (2) 1.-in. lumber sheathing used green and dry and applied in a longitudinal or diagonal orientation; (3) different nailing patterns; (4) variations in boundary member construction; (5) presence or absence of bridging and blocking; (6) different corner connections; (7) use of metal corrugated fasteners; and (8) presence or absence of skylight openings.
Download or read book Tests on Light Gage Steel Diaphragms written by Tamirisa Venkateswara Sree Rama Appa Rao and published by . This book was released on 1966 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analytical Development of Capacity Design Factors for a Precast Concrete Diaphragm Seismic Design Methodology written by Ge Wan and published by . This book was released on 2008 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of the dissertation work is to examine the capacity of precast concrete diaphragms. This work is part of a multi-university research effort to develop a new seismic design methodology for precast/prestressed concrete floor diaphragms. To accomplish this, two-dimensional finite element (FE) models of precast floor diaphragms are created, including new elements to match the response of reinforcing details under combined forces. Using these models, nonlinear static"pushover"analyses are performed by applying body forces in the plane of the floor. The analyses are composed of three major parts:(1) Parametric studies to determine the required diaphragm shear strength relative to design (flexural) strength, termed"shear reinforcement overstrength", to promote a ductile mechanism in precast diaphragms. The performance of precast diaphragms with different shear reinforcement overstrength is examined. Appropriate shear reinforcement overstrength design factors are proposed to produce certain performance targets, in terms of a number of key parameters related to diaphragm geometry and the properties of the diaphragm reinforcing details.(2) Parametric studies to examine the effects of"secondary"diaphragm elements (spandrels, internal beams) on precast diaphragm behavior. Though not directly counted in design to participate diaphragm action, the secondary elements and their connections to the main diaphragm may modify the strength, stiffness and deformation capacity of the diaphragm. Analytical studies are performed to examine their effect on the global characteristics and local demands of precast floor diaphragms. The parameters evaluated include the characteristics of the connection details, the seismic hazard level used in design, diaphragm geometry, and layouts of spandrels and internal beams.(3) Development of a rational method for calculating the service stiffness and yield strength of precast concrete diaphragms. The method involves input of diaphragm geometry andreinforcing details. The method is verified analytically through comparisons to a set of FE analyses for an idealized diaphragm representation (regular single span diaphragm idealized with simple end supports). The method verified for a single set of diaphragm reinforcement details is used to estimate the properties over a range of untopped and topped diaphragm systems. Consideration of spandrel and internal beams in the method is discussed.
Download or read book International Building Code 2015 written by International Code Council and published by International Code Council. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers the latest regulations on designing and installing commercial and residential buildings.
Download or read book Structural Performance of Light Gage Steel Diaphragms written by Larry Donovan Luttrell and published by . This book was released on 1965 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precast Concrete Diaphragm Design by ASCE 7 16 written by Brandon Cook and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Floor and roof diaphragms are an important aspect of a building's structural lateral system. The diaphragm resists in-plane seismic loads and transfers them to the vertical lateral force resisting system. If they are not properly designed, the failure could be devastating. After the 1994 Northridge earthquake the failures of multiple precast structures were investigated, and it was determined that inadequate diaphragm design was the cause of the failures. It was found that previous code provisions underestimated the diaphragm design forces. Additionally, diaphragms were assumed to behave elastically during seismic events, but it was observed that a large earthquake could cause inelastic behavior of diaphragms. Code provisions prior to the ASCE 7-16 determined diaphragm design forces based solely on the fundamental modal response of structures. However, further research proved that higher modes also influenced diaphragm forces. Therefore, a change was warranted to diaphragm design provisions in the ASCE 7-16. The diaphragm design provisions in the ASCE 7-16 ensure adequate ductility and strength of diaphragms and provides different options for elastic or inelastic diaphragm design. Not all design options are applicable and permitted for every scenario. The selection of the design option will depend on the seismic design category, the geometry of the diaphragm, and the number of stories of the building. The new diaphragm design provisions in the ASCE 7-16 are required for precast diaphragm design. This report provides a detailed design procedure for precast diaphragms and briefly discusses the research done on precast diaphragms that led to the provisions in the ASCE 7-16. In addition, a parametric study was conducted to illustrate how the design options change the diaphragm design forces and required reinforcement.
Download or read book Rapid Visual Screening of Buildings for Potential Seismic Hazards Supporting Documentation written by and published by Government Printing Office. This book was released on 2015 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Rapid Visual Screening (RVS) handbook can be used by trained personnel to identify, inventory, and screen buildings that are potentially seismically vulnerable. The RVS procedure comprises a method and several forms that help users to quickly identify, inventory, and score buildings according to their risk of collapse if hit by major earthquakes. The RVS handbook describes how to identify the structural type and key weakness characteristics, how to complete the screening forms, and how to manage a successful RVS program.
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 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Designing for Earthquakes written by Federal Emergency Management Agency and published by www.Militarybookshop.CompanyUK. This book was released on 2006-12 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This full color manual is intended to explain the principles of seismic design for those without a technical background in engineering and seismology. The primary intended audience is that of architects, and includes practicing architects, architectural students and faculty in architectural schools who teach structures and seismic design. For this reason the text and graphics are focused on those aspects of seismic design that are important for the architect to know.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1948 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidelines for earthquake resistant non engineered construction written by Arya, Anand S and published by UNESCO. This book was released on 2014-08-25 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2012 International Building Code written by International Code Council and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers the latest regulations on designing and installing commercial and residential buildings.
Download or read book Tentative Provisions for the Development of Seismic Regulations for Buildings written by Applied Technology Council and published by . This book was released on 1978 with total page 556 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:
