Structural Safety Gets Close Look As Dust Settles

AIDEEN MURPHY returned to her apartment here this week to find the building still standing but leaning so far to one side that even the slightest force might turn it into rubble. ``I didn't realize it would look like the leaning Tower of Pisa,'' she says. ``I'll have to find a sturdier building.''

Ms. Murphy is one of millions of Bay area residents trying to return to normalcy in the wake of the second most catastrophic earthquake in American history.

Three days after the earth moved, a nervous calm is descending on the area as cleanup continues and the full impact of the quake begins to emerge.

The tale of the temblor of '89 is one of individual heroism and community esprit de corps - of police who risked their lives to pull victims from tombs of debris, of volunteers who directed traffic and thwarted looters in the first frenzied hours, and of residents who have offered what they have to those who are now without.

Yet it is also a story of how destructive nature can be and a sober reminder of the distance man must still go to cope with its various fits and moods. In weeks ahead debate will likely swirl around two central questions:

Why did certain roads and bridges fail when many engineers thought they should have been able to withstand the quake?

What can be done to ensure that these and other structures do in the future?

Federal and state investigations into the collapse of a 1 1/4-mile section of Interstate 880 in Oakland appear likely. The upper deck of the highway fell on the lower deck during rush hour, accounting for as many as 250 of the estimated 270 quake deaths, officials say. Also likely is an investigation into reasons for the damage to a portion of the San Francisco-Oakland Bay Bridge.

After touring the damage this week, California Gov. George Deukmejian called for an investigation into the highway collapse saying he was ``greatly distressed'' the structures did not withstand the 6.9-magnitude temblor. Congressman Ronald Dellums (D) of California was more pointed:

``This should never happen again,'' Representative Dellums said. ``People should not have to deal with the fear of traveling on a structure that could collapse at any time.''

The din will likely increase as the economic impact of the earthquake grows. San Francisco Mayor Art Agnos now puts the damage in his city alone at more than $2 billion. Millions more was incurred in Oakland and areas to the south.

Just who will be paying for all the destruction is already becoming a testy issue. Repairing the crippled highway network, for example, will cost at least $500 million, according to state transportation officials. Vice President Dan Quayle surveyed the damaged region this week and promptly promised full federal support.

But Mayor Agnos, among others, detected equivocation in his commitment and is pushing for Uncle Sam to pay for all of San Francisco's $2 billion damage.

The quake that struck at rush-hour on Tuesday has left a peculiar patchwork of destruction. Oakland experienced the largest human toll. The collapsed freeway looks like Beirut - fissured tar and huge sections of concrete pressed on top of scores of cars.

In salt-scented Santa Cruz, the city 50 miles south of here (just 10 miles south of the quake's epicenter), the devastation was predictably severe.

Four people were reported killed and about one-third of Santa Cruz downtown mall area - the city's heart - was destroyed. As much as three-quarters of the area's mobile homes were knocked off their foundations. Local authorities estimate at least 40 other structures in the area were damaged.

In San Jose, 18 miles north of the epicenter, the quake's imprint was far less noticeable. Experts attribute the different impacts to differences in geology, construction, and proximity to the epicenter. San Jose may have escaped catastrophic damage because much of the city sits on stream deposits somewhat firmer than the bay mud and fill that underlie portions of San Francisco's waterfront.

The impact on San Francisco was particularly fickle. Many of the downtown high-rises appear undamaged. But the Marina District, a toney, upscale area near the waterfront, was severely hit. The area sits on soft landfill, making it particularly vulnerable to the earth's upheavals. Many structures in the area are also made of unreinforced masonry.

Several engineers said the city was fortunate that the quake did not occur closer to San Francisco since the intensity of ground shaking is generally strongest near the epicenter.

``If it had been [closer], you would have seen dozens more buildings collapsed,'' says one prominent area structural engineer.

As it was, the impact was not trivial. Many buildings in the area ended up as rubble. Sidewalks buckled like pup tents. Cracks web the streets. It is from this district that many stories of human survival are emerging.

Jennifer King and Tim Fredel, for instance, arrived home from a honeymoon in Maine two hours before the quake occurred. They walked into their apartment to a surprise candlelight dinner party. Just as they sat down to eat, the earth quivered. ``It was amazing,'' says Ms. King. ``We're lucky we survived.''

While Jennifer and Tim plan to stay in the area, Kristy Schlatter is moving out. Her three-story building was knocked so far askew that it will have to be demolished.

``I don't want to live here anymore,'' she says, peering up at her sagging building, which she cannot even enter to retrieve her possessions. ``I don't want to deal with it anymore.''

Utilities are being restored in most areas, though certain pockets will be without power for several weeks. About 300,000 customers south of the city remained without power early Thursday.

The city, though, is slowly regaining its footing. As it does, however, residents will have to begin focusing on a long-term concern: how to make sure the area's buildings are quake-proof.

For as scientists are quick to point out, aftershocks are expected for months to come. The US Department of the Interior Geological Survey Center warned warned that although the likelihood was ``remote'' there is the possibility of another large earthquake in coming days.

``This was not a major event,'' says Peter Yanev, a structural engineer. ``It was just a big warning for us.''