Evaluation of Dynamic Response Analysis Comparing with Actual Behavior of Concrete Bridge Damaged by Earthquake

许多钢筋混凝土桥梁在兵库县南部地震中受损严重。然而，也有一些桥梁几乎没有受损。重要的是使用相同的分析工具对这两座桥梁进行分析，并评估模拟损伤和观察到的损伤的差异。本研究的目的是通过实际行为与模拟行为的对比来验证分析工具的有效性。(1)利用断层模型获得了兵库-肯-南地震作用下三洋新干线混凝土桥墩受损部位的地震波。利用所开发的地震波，根据土体特性计算三维输入地震动。(2)利用计算得到的地震动值，对三洋新干线九座损伤桥梁和两座非损伤桥梁进行了三维非线性动力分析。在对这些桥梁进行建模时，采用平面内理论定义的梁柱单元来表示钢筋混凝土桥墩，用三维实体弹性单元来表示钢筋混凝土板。假定这些楼板在地震中没有损坏。根据经验公式对桥墩的抗剪承载力进行了计算。通过比较各时间步的响应剪力和承载能力来进行破坏分析。结果表明，桥墩的反应剪力略大于所有破损桥梁的抗剪能力。(3)混凝土结构地震反应分析存在三种不确定性：地震动不确定性、结构模型不确定性和分析工具不确定性。研究发现，为了预测结构在强震作用下的行为，需要利用结构所处位置的三维地震动输入数据进行三维非线性反应分析。

Many reinforced concrete bridges were severely damaged by the Hyogo-ken-nanbu Earthquake. However, there were also some bridges that suffered almost no damage. It is important to analyze both these bridges using the same analytical tools and to evaluate the differences in the simulated and observed damage. The purpose of this study is to verify the analytical tool by comparing between actual behavior and simulated one.The following studies were conducted in this research:(1) The seismic wave at the locations of damaged concrete bridge piers at Sanyo Shinkansen under the Hyogo-ken-nanbu Earthquake obtained using the fault model was developed. Three dimensional input ground motion was calculated in the basis of the soil characteristics using the developed seismic wave.(2) Three dimensional nonlinear dynamic analysis was conducted using the calculated ground motion at nine damaged bridges and two non-damaged ones in Sanyo Shinkansen. In modeling these bridges, beam/column elements defined by the inplane theory were used to represent the reinforced concrete piers and three dimensional solid elastic elements represent the reinforced concrete slabs. It is assumed that the slabs are not damaged during the earthquake. The shear capacity of the pier was calculated based on the empirical equation. The failure analysis was performed by comparing the response shear force and capacity at each time step. As a result, it is clear that the response shear forces of the piers are a little larger than the shear capacities at all of the damaged bridges.(3) There are three kinds of uncertainty to conduct the seismic response analysis of concrete structures; the ground motion, modeling of structures and analytical tools. From this research it is found that three dimensional nonlinear response analysis using the input data of three dimensional ground motion at the location of the structure is necessary to predict the behavior under severe earthquake.