100 likes | 212 Views
TOHOKU, JAPAN EARTHQUAKE RE-THINKING SAFETY OF HIGH-RISE BUILDINGS AND RECLAIMED LAND IN TOKYO. DR. WALTER HAYS GLOBAL ALLIANCE FOR DISASTER REDUCTION. IMPACTS AND ACTIONS BETWEEN MARCH 11, 2011 AND JULY 19, 2011. TOHOKU EARTHQUAKE: MARCH 11, 2011.
E N D
TOHOKU, JAPAN EARTHQUAKE RE-THINKING SAFETY OF HIGH-RISE BUILDINGS AND RECLAIMED LAND IN TOKYO DR. WALTER HAYS GLOBAL ALLIANCE FOR DISASTER REDUCTION IMPACTS AND ACTIONS BETWEEN MARCH 11, 2011 AND JULY 19, 2011
TOHOKU EARTHQUAKE: MARCH 11, 2011 • The Tohoku earthquake, which occurred offshore in the Sendai area, had a magnitude of 9.0.
A DESIGN SUCCESS • On March 11, 2011, the high-rise buildings in Toyosu Center, Tokyo swayed for 15 minutes in an arc of up to 1.1 m (4 ft), but, as they were designed to do, the high-rise buildings, which were on reinforced concrete pilings, successfully withstood the ground shaking from the M9.0 quake.
THE INITIAL EXODUS FROM HIGH RISE BUILDINGS HAS BEEN REVERSED • After the March 11, 2011 experience, many of the high-rise residents could not relocate fast enough. • Four months later, the occupancy rate has climbed by several percentage points and occupancy is now about 95 percent.
VULNERABILITY OF RECLAIMED LAND EXPOSED • The ground shaking triggered liquefaction and other kinds of ground failure in the reclaimed land that makes up much of Tokyo, damaging underground gas, water and sewage pipes, road systems, and parking lots.
RETHINKING SOCIETAL IMPACTS: 4 MONTHS LATER • The earthquake has forced Japanese officials and professionals to re-think the best ways to protect people inside high-rise buildings in future quakes: for example, making sure that the integrity of pile foundations was not compromised on March 11th and that elevators have backup power systems.
PLANS OF TOKYO METROPOLITAN GOVERNMENT • The Tokyo Metropolitan Government plans to spend about $50.4 million yen ($ 630 million) to equip the buildings with about 150 oil dampers — giant hydraulic shock absorbers — so that the buildings can withstand strong ground shaking even better and the swaying is reduced.
EARTHQUAKE COUNTERMEASURES • Tokyo office buildings (e.g., the 54-story Roppongi Hills Mori Tower, which has Goldman Sachs and Google as tenants) are investing in countermeasures. • Mori Tower spent 10 billion yen ($126 million) on an underground gas power plant to provide backup electricity in emergencies, and to stock 100,000 emergency meals. • .