Gudang Garam Office Tower is located in Cempaka Putih, Jakarta. The tower has 25-storeys, a 2-level basement, and a total floor area of approximately 30,000 square metres. The structural system used was a reinforced concrete core and outriggers with steel frame, sitting on 1.0 and 1.2 metre diameter bored piles – seismically isolated with elastomer rubber bearings developed by Bridgestone, Japan.
The high damping rubber bearings will isolate the building from the severe ground movement that occurs during an earthquake and will protect the building and its occupants including the contents. The superstructure needed to be rigid to take full advantage of the system. For this building, we used reinforced concrete core and outriggers as the lateral resisting system. The isolation level was taken at the foundation/B-2 level, and the building was supported by a bored pile foundation. The fundamental period for the fixed base structure and isolated is 1.56 sec and 3.48 sec respectively. The shift in the period reflects the effectiveness of using a base isolation system, where the lateral acceleration in the isolated structure during an earthquake event will be much less than if it is not.