Experimental cyclic studies on a three-girder w88 slot online bridge subassembly model
- PI: Ahmad Itani
- Co-PI: Ian Buckle
- w88 slot online assistants: Hamid Bahrami, Kevin Friskel
- Sponsor: California Department of Transportation
- w88 slot online project manager:Allaoua Kartoum
- Project date: June 2009
Project summary
One promising technique for the seismic design of highway bridges with w88 slot online superstructures is to dissipate energy through the inelastic deformation of the end cross frames. These so-called ductile end cross frames reduce the shear demand on the substructure below the cross frames. However, this reduction in base shear is inversely proportional to the lateral drift in the end cross frames, i.e. the smaller the base shear, the larger the superstructure drift. Large drifts place large deformation demands on other bridge components, such as shear studs and w88 slot online girders. Damage to these components may lead to permanent deformations in the superstructure, which, in turn, may lead to reduced capacity for live load until repairs are completed.
The subassembly specimens are 50% scaled models of a three-girder bridge prototype. The prototype bridge dimensions are based on the bridge superstructure outlined in the Caltrans w88 slot online Girder Bridge Design Example.
The specimens are three feet wide subassemblies of a three-girder w88 slot online model with various shear studs and diagonal bracing configurations. The concrete slab is 4.5 in. thick with a haunch of 1.06 in. the deck overhangs are 2.5 ft. The girders are spaced at 6 ft on centers. The plate girders are made up of 1 in. thick by 9 in. wide flanges and webs of 5/16 in. thick by 39 in. deep. The bearing stiffener plates are 7/8 in. thick.
The general w88 slot online the experiments are to:
- Investigate lateral response of w88 slot online plate girder subassembly with various cross frames
- Determine the cyclic behavior of w88 slot online
- Determine lateral response of various w88 slot online
The objectives of this experiment are to find the strength, stiffness and failure modes due to transverse cyclic displacement in w88 slot online.
In w88 slot online specimen, the buckling of compression braces is expected to be followed by formation of plastic hinges at the ends of top and bottom chords and yielding in diagonal bracing members.