Evaluation of various reports regarding the effects of earthquake on spatial trusses

History and static

In this section we aim to provide a summary report of what was happened in Kobe Earthquake in Japan in terms of the level of vulnerability in spatial trusses.

This earthquake happened in an industrial state in Japan in January 17th 1995.The center of the earthquake was close to a city named Kobe where almost 1.4 million people had been living there .In this event of earthquake and the consequent fire more than 140,000 houses damaged and 100,000 square meter of living areas destroyed, 5400 were killed and almost 300,000 people became homeless.

Highways and buildings were extremely damaged. The maximum horizontal acceleration rate of this earthquake was 800/8 gal and the maximum vertical acceleration rate of this earthquake reported to be 323/2. In the aftermath crisis, many of these trusses with a wide underneath cover became a safe place for the earthquake victims to settle down. In many reports, it has been mentioned that some trusses had been damaged to a great extent, while the damage in steel trusses has been reported to be related to their supporting concrete parts.

In many cases, roof panels and their hanging parts such as speakers and headlamps had fallen down, and the roof itself was not damage.

The damaged trusses had all been in areas with more severity of earthquake and no damage was reported in distant areas.