ISDP - INTEGRATED APPROACH TO SEISMIC DESIGN OF REINFORCED-CONCRETE STRUCTURES

Limitations of present procedures for the design of reinforced concret e structures to withstand seismic loads are discussed. An integrated s eismic design procedure (ISDP) is proposed, the main features of which are (1) The automatic selection and scaling of design ground motions given the earthquake magnitude, epicentral distance, and the type of o verlying soil strata; (2) prediction of the inelastic behavior of rein forced concrete elements when subjected to random lateral loads up to and including failure; and (3) calculation of cumulative damage that i s directly correlated to observed states of damage from laboratory tes ts of reinforced concrete elements. The analytical tools required to i mplement these capabilities are discussed. New seismic design criteria are proposed, which are based on acceptable damage indices as functio ns of earthquake energy content and structural importance. The propose d seismic design approach is demonstrated by means of a practical exam ple involving the seismic retrofit of a spiral reinforced bridge colum n. This example incorporates new and existing analytical tools, and de monstrates the feasibility of the proposed approach.