Field Test and Finite-Element Modeling of a Three-Span Continuous-Girder Bridge

摘要

A live-load test and a three-dimensional (3D) finite-element (FE) model of a three-span continuous prestressed-concrete girder bridge are described in this paper. The precast prestressed-concrete simple-span girders are made continuous by pouring a continuity diaphragm between the girders ends. Special reinforcement is extended from the girders' bottom flanges into the diaphragm to ensure continuity under positive moments that result from time-dependent effects such as creep, shrinkage, and temperature gradient. This detail was adopted in a recently constructed bridge. The bridge has been instrumented with embedded and surface-mounted sensors and was monitored for over 2 years to evaluate the performance of the new continuity detail. A live-load test was carried out to evaluate the response of the new detail under truck loads. Field test data were used to validate a 3D FE model that was developed for the entire monitored segment. Once the FE model was validated, it was used to investigate the efficiency of the detail in transferring loads between adjacent girders. From the FE results, it has been found that the continuity index is approximately 88%.