Modified Layered-Sectional Analysis for Forensic Investigation

Abstract

This paper describes a modification to the layered-sectional analysis approach, which provides the engineer with a tool to assess structural behavior of concrete beams with localized damage, a problem not well suited to classical, closed-form solutions. The modified layered-sectional analysis (MLSA) framework is applied to a forensic investigation case study in which two prestressed double-tee beams are exposed to a short duration, intense fire in a parking structure. The results of the MLSA are within 1% of the case study load test, which indicates that the MLSA could be a useful, computationally efficient tool for the investigating engineer to predict the postfire serviceability and strength of damaged beams, and potentially eliminate the need for expensive load testing. A short parametric study is included for the research engineer interested in the MLSA for predicting the postdamage behavior of non-standard materials such as enhanced sustainability concrete (ESC).