Japan Analyzes Seismic Standards for Buildings Following Recent Noto Peninsula Earthquake
Japan aims to standardize seismic resistance specifications nationwide following recent earthquakes. Learn more about their efforts to examine damage to reinforced concrete buildings and implement new standards for post-revision construction.
(Photo : Pexels/Serkan GönültaÅŸ)
Reviewing Seismic Standards for Buildings
Following a sequence of significant earthquakes that have struck the Noto region in Ishikawa Prefecture, Kumamoto Prefecture, and other areas where seismic resistance is conventionally permitted to be substandard, the Land, Infrastructure, Transport, and Tourism Ministry intends to standardize their specifications nationwide. As mentioned, seismic resistance standards stipulate that structures must withstand an earthquake of magnitude six or seven on the Japanese seismic intensity scale of seven.
Nevertheless, certain geographical areas permit more lenient regulations concerning reinforced concrete structures and wooden constructions exceeding three stories in height, necessitating structural calculations. Considering that most of the damage caused by the two earthquakes was to timber houses with two floors or fewer, the authorities did not alter the coefficient since they believed its impact was minimal.
Moreover, given that the January Noto Peninsula earthquake, which measured a magnitude seven on the seismic intensity scale, also had a coefficient of 0.9, the ministry has decided to examine the system that accounts for regional variations thoroughly. An expert group intends to investigate the connection between seismic resistance and damage by surveying the damage to reinforced concrete buildings in Ishikawa Prefecture. After that, it will develop a policy by the fall of this year.
Accordingly, the government intends to apply the new standard to buildings constructed after the modification, provided that the coefficient is set to 1 for all regions. Those structures built before the revision will not be regarded as violating the legislation, and they will not be required to undergo reinforcement following the alteration.
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The Severity of Noto Peninsula Earthquake
On January 1, 2024, at precisely 16:10 Japan Standard Time, a formidable earthquake measuring 7.6 on the Richter scale shook the serene landscape of the Noto Peninsula, nestled amidst the scenic beauty of Ishikawa Prefecture, Japan. Significant earthquakes were felt in several locations since the epicenter was located at a relatively shallow depth, and a tsunami warning was issued. Over 1,500 aftershocks have succeeded the primary earthquake since then.
According to Japanese estimates, the tsunami-damaged around 160 hectares of Suzu City and Noto City. Even after the power and water supply were shut off, communication patterns were disrupted.
Necessities such as food, water, blankets, and fuel are still in low supply, and certain districts are cut off from the rest of the world due to the lack of roads. Also, fires broke out in several places due to the earthquake, and it has been estimated that the flames destroyed hundreds of homes. In addition, to spearhead nationwide relief efforts, the Japanese government implemented the Disaster Relief Act in 35 cities, 11 municipalities, and one village across four prefectures: Niigata, Toyama, Ishikawa, and Fukui.
Furthermore, on February 16, around fourteen o'clock, the local government stated that there had been 241 deaths in the prefecture of Ishikawa. In addition to this, there are nine persons currently missing in the prefecture of Ishikawa, and at least 1,296 people have been injured. It has reportedly been estimated that more than 60,614 homes have been destroyed or collapsed, resulting in around 12,929 individuals remaining in 521 centers for evacuation.
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