Ultimate Design of Hollow Thin-Walled Box Girders

The ultimate load characteristics of thin-walled box girders are investigated. The objective was to arrive at basic ultimate design criteria. Of primary importance was the development of theoretical relations that would accurately predict the ultimate load for a given cross section. The theoretical load-displacement relations are idealized to consist of a linear elastic portion up to the ultimate load and a horizontal portion at ultimate load. Four models were tested to failure to verify the theoretical relationships. Deflections, rotations, load, and strains were measured for each ultimate load test. Results indicated good comparison between experimental and theoretical values. Specific ultimate design criteria are presented and suggested design methods reviewed.