Parametrical analyses for the DDBD method error estimation with Opensees

Structural response prediction in transverse direction of continuous girder bridges based on displacement-methods like DDBD method (Direct Displacement-Based Design) presents some intrinsic difficulties related to the equivalent system representativeness and to the displacement shape assumed at the design stage. This paper presents the procedure used for the implementation of the iterative DDBD method and its results, compared with ones obtained from non-linear dynamic analyses, to verify the structural response of continuous bridges with RC piers: using Tcl scripting, 108 regular and irregular geometrical configurations have been generated, considering bridges with 3 and 5 circular piers, designed with different drift levels (up to 4%) and different procedures, and verified using different synthetic accelerograms compatible with the design spectrum. The use of OpenSees software has allowed to automatically manage the input, modeling, simulation and post-processing data for a large number of cases study.