Defying Disaster: A Multi-faceted solution
By Randy Southerland
Structural Engineer
March 2000

ot knowing of the devastation to come, Izmit, an industrial city in northwestern Turkey, rested quietly on the morning of August 17, 1999. Suddenly, they were awakened to the roar of a 7.4 magnitude earthquake. It is the sneak attack of earthquakes that make them so terrifying. You never know when or where one will hit.

Striking along the Antolian fault line, the earthquake lasted just seconds, but in that brief moments the human and physical landscape was destroyed. Moving with devastating power, its deadly force caused thousands of buildings to collapse, trapping or killing tens of thousands of people.

In the horrific aftermath, it became apparent that poor construction, not the trembling earth alone, was also responsible for the numbing loss of more than 16,000 people. A horrified and grief-stricken public quickly realized that the human cost could have been much lower if the buildings in which so many slept had not been so poorly constructed.

The story was replayed again on September 21st when an earthquake in Taiwan killed more than 21,000 people. Another severe earthquake struck Mexico a couple of months later. Plates have been rattled off of shelves by small quakes in places as unlikely as middle Georgia.

The fury of nature is an all too familiar story that takes different forms in different locations.

Hurricanes spawned in the Atlantic make their way to land every year and wreak havoc on everyone and everything in their path.

Hurricane Floyd drove 2.6 million coastal dwellers inland from Florida to north Carolina when its massive energy buffeted the East Coast last September. High winds and rain caused billions of dollars in damage.

Hurricane Andrew’s devastation in 1992 was the most expensive, causing $25 billion in property damage, with about $18 billion of that insured. Twenty-six people died as a result of its power.

In just four years, four of the Atlantic’s most powerful hurricanes wrecked coastal North Carolina. In 1996, Bertha and Fran made landfall at Cape Fear. Last year, tens of thousands of North Carolinians were evacuated from the path of Hurricane Dennis. Two weeks later, Floyd left behind extensive flooding and beach erosion.

Inland areas are not without threat either. In the first week of January, tornadoes roared through the western counties of Kentucky causing extensive damage to homes and businesses.

Although nothing can be done to stop Mother Nature’s wrath, plenty can be done to prepare for it. This recent string of natural disasters is a wake up call to the many communities around the country that have not taken precautions.

Understanding the Extent of the Problem

At one time, the government’s resources allocated for natural disasters went primarily to disaster relief. Today, the trend seems to be shifting towards preparedness through education, retrofitting of existing structures, research, code development, and code enforcement.

For many areas of this country, education is essential. In order for communities to take initiatives seriously, they must understand the potential for disaster.

In an address to Congress last year, Michael J. Armstrong, associate director for mitigation with the Federal Emergency Management Agency (FEMA) warned, “A large magnitude earthquake located under one of several urban regions in the United States could cause thousands of casualties and losses approaching $200 billion.” He noted that all but seven states have the potential for considerable seismic activity. California’s Northridge earthquake in 1994, a moderate 6.7 on the Richter scale, centered on the fringe of a major metropolitan area, caused $40 billion in losses by some estimates. One year later, the Kobe earthquake in Japan demonstrated the impact of a large scale earthquake directly under a major metropolitan area.

While everyone understands the impact of earthquakes in California, there is also potential for devastation in the East. The New Madrid Fault, a 120-mile crack running from northeast Arkansas to southern Illinois, has been quiet since the winter of 1811-12 when its violent shifting caused the Mississippi River to flow backwards. It won’t be silent forever and its heaving force could rattle a 200,000 square mile affecting 14 million people. Experts say there is also a high potential for earthquakes in coastal South Carolina as well as the Pacific Northwest.

There are initiatives throughout the country to help us prepare for disaster. This article will take a brief look at efforts of state and federal agencies, organizations, and the private sector, to help make this nation a safer place for everyone.

Putting Seismic Research to Use

The Building Seismic Safety Council (BSSC), the Applied Technology Council (ATC) and FEMA translated the results of research and technological development into its “Recommended Provisions for Seismic Regulations for New Buildings and Other Structures.” The provisions present standards and guidelines for design and construction of buildings subject to earthquakes throughout the country. It is now widely used by practicing design professionals and building officials.

This document has either been adopted or has influenced changes to the seismic provisions of three model codes. In addition, it recently became an integral part of the new International Building Code developed by the code organizations.

The 1997 edition of the National Earthquake Hazard Reduction Program (NEHRP) provisions made available new seismic design maps and design procedures based on seismic hazard maps developed by the U.S. Geological Survey. It also presented the latest thinking on steel design from the Northridge earthquake experience.

“They found that when all the energy was imparted in one shot, something had to give and a lot of stuff did break. The biggest thing they found was that if you made everything totally rigid it winds up giving,” said Ray Moore, an engineer with Los Angeles-based J.A. Jones Construction. “So they’ve gone back to some of the older ways of thinking, calling for buildings to be a little more flexible. So when the earthquake hits, (a building) moves here and there to impart its energy, but it isn’t sitting there trying to take it head-on.”

“One of the critical lessons of the Northridge earthquake was the brittle fractures of the beam to column connections in welded steel, monument-resisting frame buildings,” Armstrong told Congress last year. “While no casualties or collapses occurred, a wide range of brittle connection damage has been found in almost 200 buildings, although the number of buildings suffering severe damage was far less. The effect of this damage was a loss of confidence in the codesand design procedures and a concern that these structures may not be safe.”

Production of the 2000 edition of the NEHRP Provisions in now underway and it is also expected to be highly influential in the design community.

But FEMA isn’t just interested in new construction, “FEMA’s goals are twofold,” said Brian Cowan, an official with the FEMA Disaster Mitigation Office, “The first is to make sure new construction is built to a high seismic standard and second is to reduce the risk of existing structures through rehabilitation.”

The “NEHRP Guidelines for the Seismic Rehabilitation of Buildings” and its commentary has become the technical criteria handbook for rehabilitation work on all building types. It presents different design approaches based on building location and seismic threat.

The guidelines for rehabilitation work, however, are very much a work in progress with changes and updates being made as knowledge and research increase.

“The guidelines are called a ‘pre-standard,’” said Jim Stamper, an engineer with Atlanta-based Heery International who is engaged in producing seismic evaluations of several federal buildings in the Southeast. “The standards are a moving target.”

“As is often the case with new advances in any field, potential users need to be convinced that the new information yields rational results, is not too difficult to apply, and is not too restrictive,” said Armstrong. “The seismic engineering community is no exception.”

To demonstrate the value of the guidelines, FEMA sponsored a case study of the seismic design of 41 federally owned buildings in areas around the country. Private engineering firms prepared designs based on the provisions. Their results are now published as FEMA 343.

Federal Buildings Retrofitted for Earthquakes

FEMA is also leading the charge to make the nation’s federal buildings safe. Under executive orders first issued by President Bush, all federal agencies have undertaken an extensive analysis of their owned and leased spaces for seismic vulnerability.

In addition to setting seismic standards that the agencies have to follow, the order also required them to conduct an inventory of their buildings and estimate cost of rehabilitating those that needed it by December 1, 1998.

It fell to FEMA to prepare and submit to Congress by December 1, 2000 “an economically feasible plan” for bringing these buildings up to standards. It will not be easy, or cheap, according to government officials.

“The number is big—about $30 billion for all federal agencies. General Services Administration’s portion, nationwide, is about $3.7 billion and that’s only for seismic strengthening,” said Bela Palfalvi, seismic director for GSA’s Region 9, which encompasses Western states and Hawaii.

Palfalvi explained that the costs of retrofitting could be a lot higher. Along with retrofitting for seismic standards, the project might also have to include upgrading accomodations for the handicapped and removing hazardous materials like asbestos with a price tag rising as high as $100 billion.

“We’re hoping to get Congress to authorize some money specifically for this project in a 20 to 30 year plan,” said Palfalvi. “There’s no way we’re going to get everything in one shot. Until we get it (the money) there’s nothing we can do.”

Utilizing the services of the Army Corps of Engineer’s Engineering Construction Research Laboratories, FEMA is compiling a database of buildings. A report is now being prepared for Congress on the costs and how to tackle the long list of buildings that need repair.

“One of the proposals in this package to Congress is the priority,” the GSA official observed. “The list is going to include essential facilities first in the high seismic zones. These facilities have to be operating during and after an earthquake—such as the FAA (Federal Aviation Administration) facilities, security centers, IRS, and the SSA (Social Security Administration) regional payment centers. Part of the report is concerned with determining which facilities are essential. Then you look at the buildings which performed poorly in the last earthquake, such as unreinforced masonry and adobe buildings. Then you go down to moderate seismic zones with whatever money is left.”

Making California Hospitals Safe—for a Price

While seismic retrofitting is getting attention throughout the country, California still remains the leader in seismic legislation and education. From Earthquake Preparedness month in April—when the governor urges the citizens to “duck, cover, and hold,” to passing stringent codes, the state leads the way, with good reason. During the 1990s, the area experienced 12 major earthquakes of magnitude 4.5 or higher.

California is now getting ready to spend billions of dollars for seismic retrofitting of all its hospitals. Under legislation passed following the Northridge earthquake in 1994, all of the state’s 600 hospitals must meet strict new Structural Performance Category 3 requirements by 2030, no exceptions. The facilities need seismic updates or they must close.

“After we had the Northridge earthquake here, the only two hospitals that failed were those built before the installation of the Office of Staewide Health Planning and Development (OSHPD),” explained Moore, who serves as preconstruction manager for J.A. Jones. “As a result, they passed Senate Bill 1957, which required that all hospitals be upgraded to current code.”

While the legislation gives hospitals a lengthy period to accomplish this task, the shear size of the effort could seriously effect the viability of many hospitals. Private hospitals are using their own funding, without state assistance to meet a timetable that mandates extensive upgrading of facilities.

Many retrofit jobs are completed; however, hospitals are now looking at major replacement work for those facilities that cannot be brought up to code simply through retrofit alone.

“That is substantial because there are many hospitals built prior to 1974 when Title 22 and 24 (of the California Building Code) were made into law regarding the seismic requirements for health care facilities,” Moore said.

The measure is designed to ensure that acute care facilities not only survive an earthquake, but also keep serving the public after the tremors have ceased. The dollars required to meet the standards are substantial as well, according to Mark Vogele, manager of special projects/health care with J.A. Jones.

“I’ve heard people say it’s as high as $20 billion, but I think it’s more in the neighborhood of four to six billion,” he said. “By 2030, when it is all completed, we might have spent $15 billion to upgrade hospitals.”

While the effort has been sometimes painful one for hospitals required to spend upwards of $200 million or more to make their facilities safe, it has produced considerable new business for architects and structural engineers.

“Some people have called it the Guaranteed Employment Act for architects and engineers,” joked Vogele. All kidding aside, he added that, “For some, this is going to be the ‘hospital closure’ act when it is all said and done. A lot of the private hospitals are going to have serious problems.”

Every hospital or acute care facility in the state that is governed by the OSHPD must comply with these strict new provisions.

“It basically comes down to the question of ‘are there beds and do patients spend the night there?” said Moore.

“It there’s a day surgery facility on a hospital campus and that facility is tied into the central plant then it might be covered by OSHPD because it’s hooked up to the others,” Vogele said.

Project Impact for Safer Communities

While earthquake provisions seem to be the focus throughout the nation, there are many other natural threats—high winds, flooding, landslides, and fires. All these calamities have cost FEMA more than $25 billion over the last decade to help local communities repair and rebuild.

As stated earlier, the emphasis is shifting toward preparedness. TO the end, FEMA started Project Impact, a nationwide effort which concentrates on education and retrofit, one community at a time. This $25 million a year program launched in 1997 provides funds, expertise, and education available for a wide variety of projects designed to make communities more disaster resistant. More than 200 communities and 1,100 private corporation partners have joined in this effort, which allows communities to assess their own vulnerability to disasters and then develop ways for mitigating the damage that can result from a particular calamity.

The agency has also made available a series of “disaster mitigation grants” to states and local communities. These grants have made possible a wide variety of mitigation efforts ranging from educational programs to better construction methods to the outright purchase of homes in dangerous areas such as flood plains or landslide areas.

In Chesapeake, VA for example, FEMA awarded the city a $300,000 grant for public education on disaster preparedness, according to Bob Smalley, city code enforcement administrator.

In this sprawling city situated some 20 miles inland from the Chesapeake Bay, winds generated by frequent hurricanes are the threat. Local builders, in conjunction with FEMA, constructed the “Hurricane House” for the local Tidewater Builders Association home show. The $330,000 house boasts hurricane-resistant clips and fasteners, wind-resistant shingles, foundation anchor strips, hurricane strength doors, and a reinforced concrete safe room off the master bedroom that can withstand 250 mph winds.

“Ever since Hurricane Bonnie (in 1998) we’ve been thinking about how we can prevent disasters in the future,” said Smalley. “We’re primarily interested in wind design and increasing the awareness of the damage that wind can do in this area.”

The hazard mitigation grants provided by FEMA have not been limited to educational efforts. They have also gone to prevent disasters from reoccurring. Last year, for example, monies were used to purchase property in Oakland, CA threatened by landslides and to evaluate the seismic safety of buildings throughout the city. The city was also able to establish a low interest loan program for those interested in retrofitting their homes.

Through out the East Coast, the grants have also been used to purchase homes and property located in flood areas.

In Virginia’s Dockside area of Southhampton County, residents are prepared to avoid the damage caused in many areas of the coast by extensive flooding.

When local officials signed up with the National Flood Insurance Program, they agreed that all new homes had to be elevated at least four feet to the 100-year flood level. Some local homeowners went even further and elevated buildings eight feet.

The extra effort paid off last year when heavy flooding from the hurricanes caused water levels to swell three to five feet above the 100-year flood level. Out of the 30 homes in the area, about 20 had seven foot flood waters in their first floor living areas.

Educating the Public through Technology

As part of its educational efforts, FEMA has also funded the devlopment of HAZUS (Hazards US), a standardized disaster loss estimation model. Developed b the National Institute of Building Sciences under contract to FEMA, it is the first nationally applicable methodology that can be used to determine and graphically display losses that could occur as the result of a given earthquake.

The goal of FEMA is not just to tell builders what standards they could use in constructing buildings, but also allows them to question whether they should build in a particular location at all.

“It’s part of our efforts with private partnerships such as business to take a look at their earthquake risks,” said Eliza Chan, a spokesperson for FEMA’s Region 9 office in San Francisco. “HAZUS is basically a GIS program that allows businesses to figure out their own earthquake risks for their locations.”

The software includes modeling capabilities, as well as an extensive inventory of GIS-located infrastructure, and has enabled users to determine the degree to which losses could be reduced as a result of mitigation actions.

Emergency managers are now using HAZUS as a planning tool to predict the impact of an earthquake in their area. HAZUS can also be used in the immediate aftermath of an earthquake as a means to quickly estimate areas of severe damage.

“A simplified version of the HAZUS program is available on the FEMA’s Web page,” Chan noted. “It shows how much risk is associated with a particular location of the country by zip codes and landmarks.”

FEMA officials say HAZUS software is a valuable tool in estimating and planning for earthquake risk.

Throughout the nation, government and private industry are taking an increasingly proactive effort to mitigate the hazards of earthquakes and other risks. While these efforts cannot prevent the kinds of disasters that have plagued mankind since the beginning of time, structural engineers, through the use of modern planning and technology, can save money and protect the most valuable of all human commodities—human life.