Collapse Mechanism and Full-Range Analysis of Overturning Failure of Continuous Girder Bridges

In recent years, failings of girders due to overturning in continuous girder bridges have repeatedly occurred China. To investigate the collapse mechanism and also evaluate rationality anti-overturning design method using beam element models that are commonly adopted practical design, detailed 3D finite solid a typical single-column pier three-span box bridge were built full-range numerical analysis was conducted. The included prestressing effect diaphragms. Both boundary geometric nonlinearities taken into consideration. Bearings modeled considering actual construction dimensions pot rubber bearings, material characteristics conditions pads, contact properties between each part bearings. results revealed behavior approached nonlinear state at onset first bearing disengagement; rotation (overturning) gradually transitioned from deformable-body rigid-body rotation; all end middle bearings had been disengaged totally or locally ultimate failure. showed disengagements would lead ineffectiveness constraint transverse direction, which significantly reduced load structural ductility before final collapse. Prior disengagement, vertical reactions calculated model good agreement with those model, while not. behaviors inaccurate after disengagement movement axis transition failed be realized. Reliable stoppers tensile anchors sections recommended efficiently improve stability design.