Japan: Strict Building Codes Save Lives

Hidden skeletons inside high-rise buildings, extra steel bracing, giant rubber pads, and embedded hydro-seismic shock absorbers help modern Japanese buildings withstand most earthquakes. Across Japan's coastline, tsunami warning signs, high seawalls, and clear escape routes have helped protect against tsunamis.

These warnings about earthquakes and tsunamis have become part of the daily drills of the Japanese people. This also explains why Japan is the country with the best disaster reduction in the world in the face of the dual disasters of earthquakes and tsunamis. Although the final casualties are still unknown, there is no doubt that they have saved lives.

Earthquakes are much more common in Japan than in the United States, and Japanese building codes are much stricter, such as how much sway buildings can withstand in an earthquake.

Since the 1995 Kobe earthquake, which killed more than 6,000 people and injured more than 26,000 others, Japan has poured huge resources into research on earthquake-resistant structures, including retrofitting the country's old, fragile building structures. The country has spent billions of dollars developing state-of-the-art technologies to withstand earthquakes and tsunamis.

Japan has taken the lead in the United States in installing advanced "isolation pad foundation devices" and "energy dispersion units" in new buildings to resist the shaking of the earth's crust in earthquakes.

The "isolation pad foundation device" is made of huge rubber and steel structural pads installed at the bottom of the building, and the "energy dispersion unit" is installed at the skeleton of the building structure. They are "hydraulic cylinders" that can be stretched to slow down the shaking of buildings and reduce the impact of energy.

Of course, nothing is completely solid. Structural engineers monitored the event closely and the death toll continued to rise as more information became available. "From the TV footage, it looks like the old buildings have all collapsed," said structural engineer Dr. Jack Moehle of UC Berkeley.

In the '80s and' 90s, Japan showed people what a tsunami was. They built a lot of concrete breakwaters, some of which were 40 feet high, to be the first line of defense against the sea. In some coastal towns, when an earthquake occurred, a network of sensors would send out alarms to every resident's home. Automatically close the sluice to prevent upstream flood backflow.

Critics of the breakwaters consider them unsightly and environmentally damaging, saying they give the illusion of protecting coastal residents from regular evacuation drills. Moreover, it affects the seascape of the residents and the effect of watching the wave shape.

In some of the affected areas of Friday's tsunami, the sea water overflowed the breakwaters. Japanese engineer Kit Miyamoto said, "The tsunami rushed up the breakwaters in Sendai, swept away cars, houses and farm tools, and then reversed its direction and swept into the sea. Due to the burst of the gas pipe, Some of the houses were in flames.

Rich Eisner, a retired tsunami preparedness expert who attended a Friday meeting of the National Institute of Standards and Technology in Gaithersburg, said "public education in the Japanese community" had saved many lives.

Unlike Haiti last year, where shoddy construction led to a large number of deaths, in China, the 2008 Sichuan earthquake, where a large number of buildings that did not meet building codes led to destructive deaths. Japan enforces some of the world's strictest building codes, and Mr. Moehle, an engineer at Berkeley, said Japanese buildings are even stiffer than comparable California structures in the same earthquake zone. Japanese building codes allow the top of a tall building to sway without collapsing during an earthquake.

"The difference is that in the United States, building standards are aimed at preventing collapses, while in Japan, because of the high number of earthquakes, their goal is to prevent buildings from shaking and causing large casualties," Mr. Moehle said.

"Japanese residential and office developers are flaunting earthquake-resistant technology as a marketing tool to promote the use of the latest technology in Japanese buildings," said Ronald O. Hamburger, a structural engineer.

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