Stability of Long-Span Pretensioned High-Performance Concrete Girders

摘要

Development of high performance concrete has increased the span length of given size precast prestressed girders up to 40 percent. While the designer's main concerns were the safety and stability of the bridge once construction was completed, attention should also be given to the temporary stresses and stability of these precast girders during handling, erection and construction. This research investigated long-span girder stability during handling and erection along with girder stability during bridge deck construction. Bulb-tee, NU (developed by the University of Nebraska) and AASHTO sections were considered. The effects of intermediate diaphragms on the behavior of long span prestressed high performance concrete girder bridges were evaluated using finite element analysis. The limit on diaphragm spacing as stated in AASHTO was found to be conservative. Different methods to improve the lifting spans of long high performance concrete girders were also recommended. The outcome of this research will expedite and help assure safety in the construction of high performance concrete long-span girders.