Recent Earthquakes in Indonesia and Japan: Observed Damage and Retrofit Solutions

Damage from two earthquakes that occurred in 2007 was surveyed. The 2007 Sumatra earthquake struck Indonesia. The results were typical of damage observed in developing countries from this magnitude event. Due to questinable detailing and inadequate construction practices, there was significant structural damage, including thousands of collapsed structures. The damage exceeded what is expected from this level of shaking. To mitigate such damage in future events, cost-effective and robust retrofits are proposed. Implementing such program would greatly reduce casualties and structural damage in the next earthquake. The 2007 Niigata earthquake struck a part of Japan that had experienced several major earthquakes since 1960’s. This was a moderate event. Since in Japan, most modern buildings use the current seismic code design and there is good construction quality, the structural damage was minor to moderate. However, there was significant nonstructural, including equipment, damage. This caused business interruptions and significant loss of operation for many industrial buildings. To alleviate such economic loss in future earthquakes, it is recommended that structural engineers increase their scope of activity and work with architects and owners and develop better detailing and installation practices for building equipment