OF EARTHQUAKES TRAINS AND AIRPORTS
Asian Property Review chats with award-winning writer and entrepreneur Christopher Dillon on earthquakes and infrastructure in Japan – 2 key issues that investors are keen to know more about before investing.
1. Japan’s construction technology, which includes advanced earthquake-resistant designs, is among the most developed in the world. How effective are the buildings against earthquakes, say, above Richter Scale 6?
Earthquakes in Japan are measured using the shindo scale, which rates them as 0, 1, 2, 3, 4, 5 lower,
5 upper, 6 lower, 6 upper and 7, where 0 is only perceptible by seismometers. In a 7, it is impossible to remain standing, buildings collapse, cracks appear in the earth’s surface and landslides occur.
Japan’s building standards are designed to achieve two goals. In a moderate earthquake, up to about
5 on the Japanese scale, the building should suffer little or no structural damage and still be safe for occupancy. In a stronger earthquake, the building should not collapse and there should be no casualties as a result of structural failure. This is important because 80% of the fatalities in the 1995
Great Hanshin Earthquake (GHE) were due to collapsing buildings.
The GHE demonstrated the importance of revisions to national building standards that took effect on June 1, 1981. Of 923 buildings surveyed in central Kobe after the GHE, 35% of those built before 1971 collapsed or were seriously damaged, 40% had moderate or minor damage and 25% had slight or no damage. For buildings constructed between 1972 and 1981, the statistics were 12%, 31% and 57%, respectively. But only 8% built after 1982 were seriously damaged, with 17% incurring moderate damage and 75% sustaining slight or no damage.