방조제 배수갑문 교량의 비선형 시간이력 해석을 통한 지진응답 평가

초록

Unlike conventional road bridges, seawall drainage sluice bridges are highly irregular composite structures with massive gates directly integrated into the piers, making them particularly vulnerable to concentrated seismic damage. To accurately evaluate complex dynamic interactions such as collisions, this study conducted a three-dimensional nonlinear time history analysis of the seawall drainage sluice bridges using ABAQUS. The concrete damaged plasticity model and connector elements for pot bearings were applied to simulate the ultimate nonlinear behavior of the structures. In total, 36 seismic load cases were considered for the analysis and scaled to peak ground accelerations based on three actual earthquake records. The results revealed distinctly different failure mechanisms depending on the direction of seismic excitation. Nonlinear collisions between the abutments and the gates occurred under longitudinal earthquakes, causing damage to the piers. By contrast, under transverse earthquakes, the heavy gates functioned as passive dampers, absorbing seismic energy and preventing the overall collapse of the piers. However, the undissipated seismic energy was redistributed to the lower sections of the girders, increasing the response spectrum amplification factor. This increase was confirmed to induce damage exceeding the functional maintenance limits, such as tensile cracking and yielding of the main rebars.

키워드