Report No.: CCEER 88-2

Title: A Micro-CAD System for Seismic Design of Regular Highway Bridges

Authors: Donald Orie, Mehdi Saiidi, and Bruce Douglas

Date: June 1988

Sponsoring Agency: National Science Foundation

Performing Organization:
Department of Civil Engineering/258
University of Nevada, Reno
Reno, NV 89557


A microcomputer model for implementing a seismic analysis procedure for bridges is presented. The method is procedure 1 of the Applied Technology Council (ATC-6) document, and is applicable to bridges with "regular" geometry and stiffness along their length.

The input portion of the program was enhanced by interfacing the program with the AutoCAD drafting package. AutoCAD is used to create points and lines which represent nodes and elements.

A parameter study examining the effects of varying the abutment and pier base spring stiffness properties was performed on a five-span reinforced concrete bridge. In addition, the limits of applicability of the computer model are established through a sensitivity study examining the effects of skew angle and curvature in a two-span bridge.
The program was named MicroSARB, and was developed in IBM FORTRAN 77 on an IBM PC-XT. The program can run on an IBM PC, PC-XT, PC-AT, or compatible with a minimum of 256K of memory.

Given the quick turnaround and accessibility of microcomputers, programs like MicroSARB provide a new means by which new and complex design and analysis methods can be transferred to design offices (Abstract by authors).