Load distribution in multi-webbed bridge structures from tests on plastic models

A multi-webbed bridge structure is one which is intermediate between the two extreme cases, i.e. a no-torsion grillage and a full-torsion slab, considered in the load distribution analyses.

The theoretical interpolation formula which gives the distribution factors for this type of construction makes use of a torsion parameter, α. Tests have been made on Perspex bridge models to determine the correct value of this parameter to be consistent with the assumptions of analysis.