Showing papers on "Earthquake resistant structures published in 1979"

Considerations in the earthquake-resistant design of earth and rockfill dams

Abstract: The factors to be considered in the earthquake-resistant design of dams are discussed and defensive measures which may be taken to mitigate the effects of these factors are summarized. Available information concerning the field performance of dams during earthquakes is reviewed and conclusions are drawn concerning the potential for earthquake-induced sliding for different types of construction materials and earthquake shaking intensities. Finally, available methods for evaluating the stability and deformations of the slopes of a dam due to earthquake shaking are reviewed and their applicability illustrated. Conclusions are drawn concerning the significance of the type of soil used for construction and the possibility of delayed failure, after the earthquake ground motions have stopped, due to pore water pressure re-distribution within an embankment. Suggestions are made concerning the appropriate role of analytical procedures in the overall assessment of the seismic stability of dams in relation to the un...

Seismic Design of Low-Rise Steel Buildings

Abstract: The behavior of selected low-rise steel buildings subjected to earthquake base motions has been studied, and recommended techniques for the earthquake resistant design of low-rise buildings have been presented. The seismic response of buildings of practical proportions when subjected to seismic response of buildings of practical proportions when subjected to seismic excitation was determined using inelastic time-history analysis. Practical methods of analysis, specifically the modal method and the quasi-static building code (equivalent lateral force) approach, have been evaluated for use in estimating seismic response. For practical design purposes it is suggested that the quasi-static approach for calculating shear distribution, overturning moments, and displacements be employed. Practical guidelines leading to building design that can resist earthquake base motion with an adequate margin of reserve strength are presented. The study demonstrates that it is possible and desirable to employ modern principles of earthquake engineering for low-rise buildings with simple framing systems.

Earthquake Response of Offshore Platforms

Abstract: The response and performance of conventional offshore platforms subjected to intense earthquake ground motions is a topic of vital concern to the offshore energy industry. The platforms discussed are steel, tubular-membered, truss-framed structures supported by tubular piles and conductors. Elastic and inelastic response, and platform system element characteristics are considered. An offshore platform system, if properly designed and carefully proportioned according to API RP 2A guidelines, can develop earthquake resistance which equals or exceeds that of comparable conventional onshore building structures.

Structural engineering handbook, 2nd edition

Abstract: Contents: Structural Analysis; Computer Applications; Earthquake-Resistant Design; Fatigue and Brittle Fracture; Soil Mechanics and Foundations; Design of Steel Structure Members; Plastic Design of Steel Structures; Design of Cold-Form Steel Structural Members; Design of Aluminum Structural Members; Design of Prestressed-Concrete Structural Members; Concrete Construction Methods; Design of Composite Beams and Girders; Masonry Construction; Timber Structures; Arches and Rigid Frames; Bridges; Buildings; Thin-Shell Concrete Structures; Suspension Roofs; Reinforced-Concrete Bunkers and Silos; Steel Tanks; Towers and Transmission Pole Structures; and Buried Conduits and Chimneys.

Seismic retrofit measures for highway bridges-volumes 1 and 2

Abstract: Since the San Fernando earthquake in 1971, interest in methods of retrofitting existing highway bridges to provide protection against collapse due to earthquakes has been increasing among highway engineers. In the majority of cases, existing highway bridges in the United States have not been designed to resist the forces generated by seismic activity. As a result, many bridges are subject to some degree of failure under strong seismic loadings. In response to this situation, the FHWA contracted with the Illinois Institue of Technology Research Institute (IITRI) in Chicago, Illinois for the development of a report on seismic retrofitting measures for highway bridges. The primary objectives of the report are to (1) provide current information on the theory and techniques for seismic analysis of highway bridges, including background material on basic structural dynamics, (2) identify the appropriate criteria necessary to decide if a bridge needs retrofitting and the type of retrofit measures to employ, and (3) demonstrate design details and installation specifications for retrofitting existing highway bridges to minimize earthquake damage. This report is in two volumes: Vol 1 "Earthquake and Structrural Analysis" Vol. 2 "Design Manual". Volume two is a design manual and contains illustrations of various retrofit concepts and specific design procedures which can be applied to existing bridges. /FHWA/

Seismic design of bridges

Abstract: This bulletin consists of 2 parts. The first part reviews recent New Zealand research on the ductile design of reinforced concrete bridge piers. The inelastic dynamic analysis of bridge structures, including the effect of soil-structure interaction, to establish the ductility demand of typical reinforced concrete bridge piers when responding to severe earthquakes was studied. Reinforced concrete bridge piers were analytically and experimentally investigated in order to establish the available ductility capacity and hysteretic energy dissipation. A study of the quantity of spiral reinforcement required to confine the concrete and to prevent buckling of longitudinal bars was an important part of the study. The second part of this bulletin presents recent developments in an alternative to the current seismic resistant design approach for bridges and other structures based usually on flexural yielding of members designed to deform in a ductile manner. The alternative method is based on two elements: firstly, the structure is supported on flexible mountings to isolate it from the predominant earthquake ground motion frequencies, and secondly, extra damping is provided to keep deflections within acceptable limits. Details of devices to provide extra damping are described. Results of dynamic analysis studies to investigate the sensitivity of seismic response to principal parameters for bridges incorporating energy dissipators are described and design charts to determine forces and displacement for various earthquake excitations are presented.

Hydrodynamic Pressures on Dams with Inclined Face

Abstract: In this paper an approximate formulation and a closed form solution are obtained, based on an extension of the elementary formulation of Von Karman.

CWPEEF’s Views on Earthquake-Resistant Design of Earth Dams

Abstract: The California Water and Power Earthquake Engineering Forum was formed in April 1945 by several major local, state, and Federal water and power agencies. The principal purposes of the Forum are to share information and stay abreast of the latest developments in the field of earthquake engineering for water and power facilities.