GRAPHICALLY-ORIENTED ANALYSIS OF POST-TENSIONED SLAB BRIDGES ON MICROCOMPUTERS. FINAL REPORT

This is the fourth in a series of reports documenting a research program aimed at detailed investigation of a new type of bridge structure that has a moderately thick, post-tensioned, concrete slab resting directly on columns without bent caps. In this program, two scaled laboratory models, named Model One and Model Two, are tested in the laboratory along with instrumentation of a full-scale 3-span bridge. Analysis of this class of bridge structure is carried out by means of a nonlinear finite element analysis code that has been specially designed to run on microcomputers. This report relates to the analysis code and is intended to serve as a user manual for design engineers. A suite of computer codes, mnemonically titled TEXSLAB, automates input of bridge geometry and loads, performs finite element simulation to determine deflections, strains, and stresses in the slab and tendons, and provides graphical output of salient quantities for the designer. A user-oriented system of menu-driven interfaces makes generation of the input model relatively simple. In addition, graphical representation of many input parameters, such as tendon profiles, allows error-checking before execution of the analysis module. Full program operation takes place on a microcomputer. This package is developed using FORTRAN 77 as the primary coding language, C as a secondary language for operating system function calls, and a commercially available graphics package for rapid visualization of results. TEXSLAB runs under OS/2 version 1.1, 1.2, 1.3, 2.0, or 2.1 with the DOS compatibility box active. File development and program execution take place in OS/2, while graphic model confirmation and examination of analysis results occur in DOS.