7. Concluding remarks
The end cross-girder plays a significant role against seismic loading, while it is located where corrosion tends to occur easily and the inspection is not necessarily easy to conduct. Against this background, the end cross-girder with inspection holes were studied. In short, the load-carrying capacity of the end cross-girder under horizontal load was investigated by the 3-D nonlinear finite element analysis. The following observations were made from the present study: (1) The inspection hole reduces the load-carrying capacity signifi- cantly: the larger the hole is, the greater the reduction becomes. (2) The influence of the inspection hole on the load-carrying capacity depends greatly on the horizontal position: as the hole approaches the center of the web, the reduction in the load-carrying capacity becomes larger. (3) Even though the loading condition is different, the standard reinforcements for a manhole help recover the load-carrying capacity of the end cross-girder with inspection holes. (4) For the reinforcement, the doubling is more effective than the stiffeners. (5) The standard plate thickness of the reinforcement for a manhole is sufficient. Further increase in the plate thickness does not improve the capacity. (6) When the size of the inspection hole is the same as that of the standard manhole, the doubling can recover the load-carrying capacity up to 90% of the original capacity. The combination of the doubling and the stiffener can achieve the almost full recovery. (7) For a larger inspection hole, even the combined reinforcement cannot recover the load-carrying capacity fully. Safety against seismic loading must be verified carefully.
