Bridge response under loading test was the interaction of various parameters. Many field tests were conducted on the existing bridges and the field test responses were suggested to calibrate the FEM for further research (Seo et al. The actual boundary condition for the bridge was quite important for analyzing the bridge structural behavior. Emon and Nowak ( 2001) proposed that the hinge-roller supports can be partially fixed (frozen) due to many factors and they found that the code-specified DF values without considering the effect of possible support fixity can be too conservative. Bridge test in Ontario had shown that slab-on-girder bridges are usually significantly stiffer in flexure because of horizontal restraint provided by the girder bearings (Bakht and Jaeger 1988). However, it was reported that even slight changes in boundary conditions have a considerable effect on the results (Schulz et al. Most hollow slab bridges in the design plan were designed as simply supported. To describe and simplify the effect of these parameters, the distribution factor (DF) is proposed by assigning fractions of transmitted load amongst the primary structural members (Harris 2010 Song et al. The live-load response of this kind of bridge could be affected by span length, bridge deck thickness and skewed angle, etc. Many hollow slab bridges are designed to be skewed bridges to satisfy the traffic requirements. It was found that AASHTO LRFD specification is conservative compared with the analysis in the FEM, while this conservatism decreased as the span length and skew of the hollow slab bridge increased. A parametric study using the calibrated FEM was then used to investigate the effect of various parameters including span length, skew and bridge deck thickness on the DFs. From the FEM, DFs for this hollow slab bridge were determined and compared with the DFs in the AASHTO LRFD specification.
The measured data in the multi-stages of the field test could be used to calibrate the support condition of the bridge and transverse connection between adjacent girders in the finite element model (FEM) using beam and plate elements.
The instruments used to record the response of the bridge were strain gauges and dial indicators. This field test was divided into two stages: a concentrated force loading test on the prefabricated girder that settled on the bridge supports before the girders were connected transversely and a vehicle loading test after the girders were connected transversely. The response of the bridge was recorded during the field test. To study this diversity, this paper presents an evaluation of lateral load DFs for prefabricated hollow slab bridges. The diversity between design and actual DFs may be varied as the bridge parameters changed. Distribution factors (DFs) for one typical cross-section as specified in the AASHTO LRFD specification can be varied when the bridge parameters such as span length, loading lanes and skew are changed.
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