What is the minimum seismic design criteria for bridges or buildings?

ASCE7-05 and latest ASCE7-10 is broadly used which determine seismic forces depending on different factors and coefficients like direction x or y, +eccentricity,time period like8 sec response, Story range top bottom, Factors like omega cd & I, Coefficien for .2 sec1 sec, site coefficient etc.

 

American National Standard Committee A58 periodically issues revisions to ANSI Standard A58 - "Building Code Requirements for Minimum Design Loads in Buildings and Other Structures." This document defines magnitudes of dead, live, wind, snow andearthquake loads suitable for inclusion inbuilding codes and other regulatory documents. The A58 Standard Committee is a broad-spectrum group of professionals from the research community, building code groups, industry, professional organizations and trade associations. Their approval of a proposed standard signifies that a consensus of those substantially concerned with its scope andprovisions has been reached, in that affected parties have had an opportunity to comment on the standard prior to its implementationand opposing points of view have been treated fairly.

 

The A58 Standard is concerned solely with structural loadings. The specification of specific allowable stresses or design strengthsfor materials of construction is outside its scope. The current version of the A58 Standard, ANSI A58.1-1972, is being revised, with a tentative approval and publication date set for1980.

 

This report addresses itself to changes to the A58 Standard which may occur subsequent to the1980 revision. Its purpose is to develop a load criterion, including load factors and load combinations, which would be suitable forlimit states design with different materials andmethods of construction. The current standard already contains a set of load combinationsand probability factors for allowable stressdesign. This Executive Summary is presented to review briefly the conclusions of the main report, giving an overview of the recommendations and a concise rationale fortheir development.