|Seismic reinforcement of viaduct columns is usually done by the steel jacketing construction method where the entire circumference of the column is cladded in steel plates. But when a columns is at the boundaries of shops, the cooperation of shops on both sides of the column is required. Gaining the cooperation of shops on both side at the same time, however, proves to be a difficult proposition.
We thus developed a reinforcement construction method where, when the cooperation of one shop can be gained, steel plates are partially installed on one section of the column in advance. When the shop on the other side is unoccupied, the remaining part of the column is jacketed in steel plates. The steel plates are not closed in construction for the advance part, so mortar can leak out. This prompted us to develop a measure to prevent leaking. When the remaining half is attached a certain amount of time after the advance construction, jacketing is done surely and aseismic performance exhibited thanks to a developed correction tool even if construction accuracy of the advance steel plates is poor or if the steel plates deform over time.