The scaled nonlinear dynamic procedure

A preliminary version of a new seismic analysis procedure is presented. The Scaled Nonlinear Dynamic Procedure (NDP) overcomes inaccuracies associated with other methods of analysis and can readily be used in conjunction with the Nonlinear Static Procedure (NSP) for performance-based seismic design and evaluation

The scaled nonlinear dynamic procedure

Although nonlinear static procedures (NSPs) have become widely accepted for use in seismic design and evaluation in recent years, their accuracy is poor for response quantities that are significantly affected by the vibration of multiple degrees of freedom (termed MDOF effects). In recent work performed for the ATC-55 project, a design-oriented approach, called the scaled nonlinear dynamic procedure (Scaled NDP), was identified for determining such response quantities for nonlinear systems. The Scaled NDP provides an alternative to current code approaches for scaling ground motions for dynamic analyses and is readily used in performance-based seismic design and evaluation. The Scaled NDP appears to provide a valid basis for establishing force quantities at stated levels of confidence and provides an indication of deformation demands for use in design and evaluation. The results can be used to determine the strengths required of members in order to ensure that ductile behavior develops, and to evaluate the deformation performance of a given design. © 2006 Elsevier Ltd. All rights reserved

The web-based World Housing Encyclopedia: Housing Constrction in high seismic risk areas of the world

Recent devastating losses in earthquakes to housing around the world highlight the need to share information on building construction practices and strengthening technologies. The Earthquake Engineering Research Institute and the International Association for Earthquake Engineering have an ongoing Internet-based project called World Housing Encyclopedia (WHE) that provides a framework for sharing such information globally (www.world-housing.net). The purpose of the WHE is to develop a comprehensive global categorization of characteristic housing construction types presented using a standardized format. The encyclopedia provides basic information on the seismic vulnerability and strengths of various structural systems and materials, useful to local, national and international public and private organizations and individuals concerned with improving the seismic resistance of a region’s housing stock. Initially inaugurated at the 2000 World Conference on Earthquake Engineering in Auckland, New Zealand, this web-based project is now in its fourth year. This paper describes the scope of the encyclopedia and provides the examples of its application

A Challenge to Earthquake Engineering Professionals

Recent earthquakes have caused unacceptably high death tolls. We, the editors of theWorld Housing Encyclopedia, believe that reducing such an un- acceptably high loss of life from earthquakes is the most important challenge facing the global earthquake engineering community. This paper acknowl- edges the continuing disparity between life loss from earthquakes in devel- oping and developed countries, and the increasing vulnerability in developing countries. A sampling of current efforts to improve construction practices in- cludes the publication of earthquake tips in India, construction manuals in Colombia, and the formation of various international networks to promote collaboration and information sharing. Future possibilities include more re- wards for research into inadequately engineered construction, greater empha- sis on small-scale, local efforts, and a stronger emphasis on advocacy.We be- lieve that all of us, as earthquake professionals, have a responsibility to make the built environment safer worldwide

Spring tube braces for seismic isolation of buildings

A new low-cost seismic isolation system based on spring tube bracings has been proposed and studied at the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Multiple compression-type springs are positioned in a special cylindrical tube to obtain a symmetrical response in tension and compression-type axial loading. An isolation floor, which consists of pin-ended steel columns and spring tube bracings, is constructed at the foundation level or any intermediate level of the building. An experimental campaign with three stages was completed to evaluate the capability of the system. First, the behavior of the spring tubes subjected to axial displacement reversals with varying frequencies was determined. In the second phase, the isolation floor was assessed in the quasi-static tests. Finally, a ¼ scaled 3D steel frame was tested on the shake table using actual acceleration records. The transmitted acceleration to the floor levels is greatly diminished because of the isolation story, which effects longer period and higher damping. There are no stability and self-centering problems in the isolation floor.</p