Highways Agency Reports

A 2-D upper-bound plastic model for the assessment of shear in concrete beam-and-slab bridges was documented in Interim Report no. 1. A more general 3-D collapse anaysis is formulated here, which involvesfailure of the slab and beams. Calibrated from the 2-D theory is extened to this mechanism analysis and comparison carried out against recent experimental tests conducted atcambridge University Engineering Department under the same contract. It is shown that the method has potential for use as a possible shear assessmenttool. It is, however, emphasised that the method relies on adequate ductility of the structure, so that the Engineer needs to be fully aware of the limited range of applicability of this plastic analysis technique. It finally concluded that further work in this field is justified as the method has proved an adequate model, based on comparisons with the few tests used as calibration.