Trepponti Bridge: From 3D Model to Preliminary Nonlinear FE Analysis

This paper aims to investigate the nonlinear structural behavior of a complex in geometry historical pedestrian bridge, the Trepponti di Comacchio (Italy), under its self-weight and the presence of settlement at one springing by seamlessly integrating a CAD environment (PoliBrick plugin) with a standard finite element (FE) software (Straus7). PoliBrick, developed by two of the authors, enables users to generate freeform surfaces that can be meshed according to custom specifications for import into FE software. This mesh also accurately replicates the real stereotomy of the curved structure under study. The main advantage of employing PoliBrick lies in significantly reducing the computational burden during the pre-processing phase of structural analysis. In this preliminary stage of the study, stereotomy is not considered to expedite FE nonlinear analyses. The mesh utilizes elasto-plastic plate and shell and full 3D elements. Material mechanical properties are assumed in agreement with both a LC1 knowledge level as defined by Italian structural codes. Results obtained preliminarily assess the state of degradation and damage observed during in-situ surveys, and represent a valuable starting point for further research.