2020 年 76 巻 4 号 p. I_320-I_336
The robustness evaluation and development of robust structure for the air-raid proof bridge are presented. The effect of damage of structural components on the performance of the bombing resistant double diagonal ten panel three span continuous truss bridge with regarded to the different robustness indices of structure are inspected by conducting linear static analysis using OpenSees software. The damage of internal indeterminacy and the damage of external indeterminacy are considered for enhancing the bombing resistant redundant robust structure. The new idea of influence lines are proposed in the evaluation of the robustness of the structure and the critical components are found out. In addition, the behavior of air-raid proof bridge for the intact and damage conditions are determined by means of damage influence lines of stresses and the real acting stresses of the detected members. The practices of improving robust structure are proposed by adding the suspension truss structure to the existing double diagonal ten panel three span continuous truss bridge and by increasing cross sections of the affected members based on the damage of critical parts of structure. In relating with the structural strengthening on the damage condition of structure, the traffic control technology from the structural engineering point of view are suggested. In order to improve the bombing resistant high redundant robust structure, the combination of different countermeasures of internal indeterminacy, external indeterminacy, suspension truss structure and estimation of cross sections of members are recommended.
