Japan’s Quake Planning Is Imperfect but Instructive

A carefully coordinated effort to predict and prepare for the next great earthquake here is without parallel.

Western experts marvel at the thoroughness of the Japanese program, leading many to wonder what the United States--and particularly California--has to learn from Japan.

A report prepared by the Southern California Earthquake Preparedness Project a few years ago concluded that many key elements of the Japanese program could be transferred to California, and in recent years the United States has, indeed, instituted some programs that are very similar to Japan’s. But there are still vast differences stemming in part from the great dissimilarities between the two regions and their people.

The most striking difference is the level of involvement by private citizens. Residents of Japan are told precisely where they are to go when the quake hits, and safe areas such as open parks have been designated throughout the city. Most residents take part in major earthquake drills at least once a year.

Other steps include creating an early warning system that will shut down some key facilities before the shock waves hit. Strict fire codes have been instituted. A huge earthquake-proof housing project has been completed, and one of the toughest structural engineering programs in the world has been instituted.

All of that represents a considerable investment in earthquake safety. Although the exact cost is hard to pin down, Western experts believe the city of Tokyo alone spends an estimated $1 billion a year on earthquake preparations.

But Japan has by no means solved all of its problems.

A taxi ride through the suburbs of this sprawling city will reveal the endless rows of small homes that many experts predict will collapse in a major earthquake. Yet there is no program to force homeowners to upgrade their structures to meet modern earthquake standards, a curious failure for a country that is hit by large quakes several times a year.

“Old-time Japanese buildings were top heavy,” Etsuzo Shima, one of Japan’s leading seismologists, said as he pointed at a building with a blue tile roof. It is even heavier than the red tile roofs that dot the hillsides and the valleys of California.

“So when the earth moves . . . “ he said, his voice trailing off.

Even commercial buildings that are used for public purposes are not required to be upgraded here unless the owner decides to modify the building in some way. In California, and particularly Los Angeles, the law has required many owners to improve their structures.

The differences between the two countries are less pronounced for newer buildings, which are required to meet a tough engineering code that has placed California and Japan on about an equal footing, officials agree.

But while the United States and Japan may share some problems and some progress, there can be no doubt that Japanese authorities have made far greater strides in their efforts to reduce the hazards from the great earthquakes that unquestionably lie in Japan’s future.

Japan is the only country in the world, for example, with a major earthquake prediction project that is integrated into its disaster planning program. Scientists here hope to predict a great quake in the Tokai area south of Tokyo in time to evacuate several crowded cities.

That prediction effort is part of a broad-scale program that involves everything from top officials to small property owners, and there is nothing quite like it anywhere else in the world.

There is disagreement over whether prediction of a major quake is indeed possible, but Japan already has taken numerous steps to reduce overall hazards when a quake hits.

“In Japan, the first thing to do is to control the fires,” said Hirokazu Iemura, a leading earthquake engineer at Kyoto University.

Iemura noted that Tokyo sustained greater damage from fire during the great quake of 1923 than it did from the quake itself. And he wonders if California is fully aware of that threat despite the fact that San Francisco also was destroyed by fire after the 1906 quake.

“Look at that,” he said, holding up a picture of fire in San Francisco’s Marina District following the Oct. 17 Bay Area quake. Iemura, who toured the area after the quake, noted that smoke from the fire was spiraling straight up.

“You were just lucky,” he said. “If there had been a wind, the fire would have spread.”

Fire is of particular concern during an earthquake because water mains can be damaged, access to the area may be blocked by debris and fire departments may be overwhelmed.

To reduce that hazard, many Japanese cities--including Tokyo--have required homeowners to reduce fire hazards, and a special effort has been made to fireproof structures along Japan’s crowded roadways.

“Now, almost all the oil heaters in the homes have automatic shut-off,” Iemura said. “If they feel the vibration (from the earthquake), they cut off.” Automatic shut-off valves are available for gas meters in the United States, but they rarely, if ever, are required by law.

Japan also has instituted an early warning system. Seismometers placed in areas along the coast, where most great quakes strike, telegraph a warning as soon as the earth begins to shake. That warning is transmitted to such things as the high-speed rail system that cuts through the Tokai region, and it shuts down Japan’s famous “bullet trains” before the damaging shock waves reach the rails.

What sets Japan’s program apart from most others, however, is the level of involvement of the public. Japan is one of the most seismically active regions on Earth, and small to moderate quakes hit here all the time. Residents of Tokyo, for example, experience earthquakes several times a year.

Most cities in Japan hold regular earthquake drills, and local residents have been told specifically where to go when the earthquake hits. Evacuation centers have been set up all over the country in areas that should be free from fire, such as open parks or along river banks.

The most dramatic manifestation of Japan’s concern over earthquakes is a huge apartment complex that was designed from theground up to withstand a major quake. The complex houses up to 6,000 families and is designed to serve as an evacuation center for 60,000 people.

The complex sits in an area that had been destroyed twice before--once by the Great Kanto Earthquake in 1923 and again by bombing raids in 1945 during World War II. Wooden structures that housed many low-income families sprouted up throughout the congested area after the war, and Tokyo officials were alarmed when they learned that the flimsy buildings had been erected on a soft, damp sedimentary basin that ranks among Tokyo’s greatest geological hazards. The ground there will be subjected to powerful shaking during a major earthquake.

Ample open spaces surround the new buildings to allow residents to stand free of falling objects during a quake. The buildings themselves include many engineering features that minimize the danger from ground shaking and fire. Even doors are designed to avoid jamming. Special evacuation routes lead to safe areas.

Enough water, food and medicine is stored in specially designed tanks at the site to take care of 60,000 people for a week.

None of that, however, came cheaply. The Tokyo Metropolitan Government spent more than half a billion dollars on the project, and no one knows what it would cost to provide similar protection to the millions of people who live in Tokyo’s crowded suburbs.

Many of the features developed in the design of the complex, however, have been incorporated in other structures throughout Japan.

Japan’s leading construction firms are also deeply involved in earthquake reduction programs, and most have their own research institutes.

The Taisei Corp., for example, has pioneered in the development of “base isolation systems” for medium-size buildings. The system isolates the foundation so that the ground can move beneath the building without endangering the structure. Similar systems have been developed in the United States.

Taisei built a four-story building at its technology research center in Yokohama “to demonstrate our technology,” said Soichi Kawamura, manager of earthquake engineering for the firm.

“Usually, a building is hitched to the ground,” Kawamura said. “But in this case the building is supported by isolated columns,” so the structure in effect stands on four stubby legs. The upper part of each leg is a steel casing, and the bottom is a bearing made of rubber and steel.

During a moderate earthquake, the bearings deform, absorbing the energy from the temblor, and then they return to their original shape. And during a major quake, the bearings can slide back and forth on massive steel plates.

The building is next door to an identical structure that has a conventional foundation. Both buildings are heavily instrumented, and the 40 earthquakes that have hit the area since the structures were built reveal that the base-isolated building shook only about one-fourth as much as the conventional building, Kawamura said.

That technique only works for medium-size buildings, and Japanese firms have developed other techniques to protect high-rises. The designs allow the buildings to sway safely, performing something like a human body--bending but not breaking.

Japanese engineers are required to design for two types of earthquakes.

“One is the small- and medium-size earthquake that occurs frequently in Japan, and the very big earthquake that is expected in the life of the building,” said Tani, of the Kikken Sekki engineering firm.

The two-pronged approach assures that a moderate quake will not eliminate the “usability of the building,” he said. “For the big earthquake, we only try to save life.”

Such engineering measures have led most Japanese experts to conclude that newer buildings will do quite well during an earthquake, a conviction that was bolstered by the success of similarly designed structures during the Bay Area earthquake in October.

But, as is the case in California, many people live in structures that were built long before modern earthquake standards were set. And, as in California, there are just too many folks, wanting to live in all the wrong places, for emergency planners to ever grow comfortable.

“It’s difficult to tell people they can’t build,” even in areas where the soils constitute a geological hazard, said Kyoto University’s Iemura. “San Francisco is like Japan; it’s very crowded. People want to accept the earthquake risk. We want to build things.”