Abstract
This paper summarizes the restoration works of Niigata J. N. R. Hospital Building which was damaged by Niigata earthquake. The building is reinforced concrete construction with 6 stories and 1 floor basement. Building area : 1269.7m^2 Total area : 8137m^2 The building was inclined by 3°24′to the transverse direction and by 29′to the longitudinal direction. The crackings of the concrete structure which was caused by the seismic vibration were hardly observed in the building. Restoration work was carried out by following way that is, the subsoil under the foundation slab was partially digged out to increase the contact pressure, at the same time, in order to take away a instability facter caused by the excavation, the building was pushed down by the jacks which was fixed on both sides of the building, therefor building was rotated slowly. In those conditions, the restoration work was carried out within 50 days. During the restoration work, the measured maximum joint translation angle of the structure was 1.7×10^<-3> Rads but generally it was about 0.5×10^<-3> Rads. When the maximum joint translation angle was measured only a few crackings was observed. The maximum difference of the floor level around the building is only about 20mm and the building was completely restored.
