| Typically, for compact girders, the Service II Limit State of the AASHTO Load and Resistance Factor Design (LRFD) Specifications (2005) governs the design by limiting the stress in the girder flanges to a fraction of the yield strength of the steel. This limit state corresponds to the overload check in the 1992 AASHTO Standard Specifications and is intended to prevent objectionable permanent deformations due to unexpected severe traffic loadings, which would impair rideability. Because the Service II Limit State: (1) is not calibrated based on LRFD methodology, (2) has an ambiguous objective of preventing "objectionable deformations" and, (3) has a profound governing impact on the design of steel girders, further investigation into the Service II Limit State is needed. Furthermore, there is a concern regarding the implications of the Service II Limit State and the effect on permanent deformations as a result of optional moment redistribution design procedures, which allow steel girder stresses to exceed the yield strength of the steel.; The intention of this thesis is to provide experimental data to further investigate the objectives of the Service II Limit State, the effects of moment redistribution design, and how they relate to one another. Therefore, the objectives of this research are to provide experimental data on service stresses versus deflection/permanent set and to provide experimental data on service stresses at various levels of moment redistribution. In an effort to realize these research objectives, background research was done regarding the origin of the Service II Limit State and other integral aspects of the design criteria. Additionally, an experiment was designed and performed on a composite continuous-span test specimen to collect the needed experimental data on strains and deflections.; The experimental research for this thesis did not provide the data necessary to facilitate further investigation into the objectives of this research due to circumstances beyond the control of the research team. However, a systematic approach was developed for the experimental test specimen design, the construction, the testing procedure, the numeric data analysis, and the graphical display of data/results. These developments will be valuable in future experimental testing of continuous-span specimens. |
