APRIL 2006 – SHAKY GROUND – By Pierre Home-Douglas

By Pierre Home-Douglas

Peter Nicholson had seen natural disasters before, but nothing prepared him for what he confronted in New Orleans. He arrived at the end of September 2005, one month after Hurricane Katrina pounded the Gulf Coast, submerging the Big Easy and wreaking utter havoc on human lives and property. “I’d seen the news stories, stuff on CNN, but the devastation was just so much more dramatic than I expected. I’ve been to post-earthquake scenes, and this was way worse. Whole areas were devastated, just gone. I’ve never seen a nuclear holocaust, but…” his voice trails off.

Nicholson, an associate professor of civil and environmental engineering at the University of Hawaii, Manoa, headed a team of engineers from industry and academia, organized by the American Society of Civil Engineers (ASCE), to try to uncover what went wrong in the aftermath of Katrina. Three other organizations, the National Science Foundation (NSF), the Army Corps of Engineers and a team from Louisiana State University also combed through the detritus left by the hurricane, looking for telltale clues.

The investigators met some daunting challenges. Nicholson wanted to get into New Orleans as quickly as possible after the disaster to gather information. That wasn’t possible. Flooding made parts of the city inaccessible. Also, Nicholson didn’t want his group to get in the way of workers attempting to repair the damage. “Plus,” he adds, “there was the little matter of reports of people going around and shooting rescue workers.”

Nicholson said his group held back as long as it could and arrived in New Orleans as evidence was already disappearing. “Bulldozers were burying evidence before our eyes. If we had waited much longer we would have missed huge amounts of evidence.” Fortunately, the investigating teams had seen enough to come up with preliminary conclusions about what had happened, which led to a joint report presented to the Senate Committee on Homeland Security and Governmental Affairs on Nov. 2.

“Peter did a fantastic job under very trying circumstances,” says Lawrence Roth, executive deputy director of ASCE, an organization that traces its roots back to 1852. “He had already headed our committee on embankments, dams and slopes, but just because he had given great service there didn’t give us any assurance that he had the leadership skills to lead an entire team in these circumstances. These people he was working with were volunteers, after all. You couldn’t fire them. You had to motivate them without a carrot or a stick. Peter did that.”

According to Joseph Wartman, a civil engineering assistant professor at Drexel University and a member of the ASCE group, the team established a camaraderie and spirit of cooperation not always found in academia. “Few things can get you more focused on your research than standing in a completely devastated area and seeing the effects of it. It got rid of the politics.” Like Nicholson, Wartman describes a scene of almost apocalyptic proportions. “It was like a neutron bomb had gone off. Many of the structures were still standing, but there was nobody there. We walked around sometimes for four or five hours in the city without seeing another human being.”

One of the big surprises for many of the investigators was discovering that the damage caused in New Orleans wasn’t simply the result of water pouring over the top of the floodwalls. That, Nicholson points out, could have been largely remedied by pumping the water back out. Instead, some of the walls and levees gave way, the result of inadequate structures and a hodgepodge of designs. The 350 miles of levees in New Orleans came in different forms, sometimes even in a single stretch. In some areas, there were simply earth embankments; in others, earth with sheet piles—corrugated metal—driven to various depths into the levees. And still others, sections with different types of reinforced concrete walls built on top of the sheet piles. The best-designed sections, so-called T-walls with a wide footing at the base, were undamaged. Trouble was, the whole network was only as strong as its weakest link. One section of levee alone was pushed back 35 feet by the force of the water.

Nicholson doesn’t use words like “preventable” in talking about what happened, and he is critical of people looking for easy scapegoats and quick answers. “It will take a long time to understand fully what happened in New Orleans.” Still, he admits that engineers are capable of designing and building a floodwall system that could shield New Orleans from even a Category 5 hurricane. (Katrina was a Category 4.) It’s a question of money. He compares constructing hurricane-proof levees in New Orleans to building structures in earthquake zones. “In one sense, it isn’t economically reasonable to build earthquake-proof buildings. Instead, we construct earthquake-resistant buildings. So we build structures that won’t collapse in a Richter 7 earthquake. To build it stronger gets into a whole cost-versus-lives issue—that’s a subject way out of my area.”

A Little More Respect for Soil, Please

Nicholson is pretty simple about what his area is: dirt. Correction: soil. “I tell my intro students that dirt is what you call it when you get it on you,” he says with a chuckle. As a geotechnical engineer, Nicholson describes himself as someone standing in the ground looking up at a building. “I’m looking at the bottom of reinforced footings, for example, and trying to figure out how the Earth is going to react to this structural member.”

Soil, Nicholson says, is a much-underappreciated material, even among civil engineering students. “It’s hard to get students enthused about soil mechanics because it’s just not as exciting—or at least it doesn’t appear to be as exciting—as, say, designing high-rise buildings.” It’s a view reinforced by the media. “When you see shots on TV of the aftermath of an earthquake, you don’t see shots of soil failure. You see things like big buildings tipped over and crumpled freeways. But often the reason structures collapse in one area and not another is directly the result of how they respond to the soil underneath it. When the soil fails, whatever on it is going down.”

Nicholson, 48, began his academic career as a geology student at Yale and later went into geological engineering. Somewhere along the way, the Rhode Island native decided that he didn’t want to end up working for a big oil company or in exploration, even though he fondly recalls climbing mountains with a rock hammer in his hand. While working on his master’s at the University of Utah, he took a couple of geotechnical engineering courses and was hooked. He admits he had always been someone fascinated with natural disasters. That interest later expanded into all types of catastrophic failures, of which dam failures are one of the most devastating examples. His 1990 Ph.D. at Stanford focused on earthquake-induced soil failure, a subject that still intrigues him. “We know how structures will respond to earthquakes, and we know how soils will respond, but we don’t fully understand the interaction between the two. We’ve learned a lot in the last 15 years, but it’s one of those examples of the more you learn, the more you realize you don’t know.”

After completing his Ph.D., Nicholson worked for a year as a senior staff geotechnical engineer and assistant project engineer in the dams division at Wahler Associates in Palo Alto, Calif., before joining the civil engineering department at the University of Hawaii. He’s been there ever since. In addition to teaching courses on soil mechanics, seismic engineering and geotechnical engineering, Nicholson serves as the graduate chair in his department. Although much of his work is still spent on research, he counts his teaching duties as extremely important. “Some people get a Ph.D. and go into university, but they just aren’t teachers. I’ve enjoyed teaching—and I think students have enjoyed me, too.” The Regents of the University of Hawaii seem to agree, awarding Nicholson an Excellence in Teaching Award.

Outside of the classroom, Nicholson is an avid skier and former volunteer fireman and trained ski patroller who says his professional studies have come in handy at times. “Landslides and avalanches are actually pretty similar,” he says. Even though they are different materials, they can still be understood with the same equilibrium analyses techniques. He continues to get his skiing fix by flying to Canada or Utah. But the Aloha State also has plenty to offer, and he spends his spare time snorkeling and surfing and honing his skills on multihull sailboats.

Even though his ASCE group concluded its preliminary assessment work in November after the joint ASCE-NSF report was released, Nicholson’s work is not yet over on New Orleans and Hurricane Katrina. In late November, he was asked to join an independent panel of experts that Defense Secretary Donald Rumsfeld asked ASCE to convene. The group will review work performed in the months ahead by the federal government’s Interagency Performance Evaluation Task Force (IPET), which will continue to collect and analyze data about how the New Orleans hurricane protection system performed following Katrina. After IPET issues its report this June, Nicholson and his group will follow up with a report of their own that will evaluate IPET’s conclusions.

In the meantime, Nicholson says that the disaster in New Orleans—the biggest civil engineering failure in U.S. history—should serve as a wakeup call to remind people of the perilous state of infrastructure in the nation. He points to the recent report card on the subject issued by the ASCE, which gave dams a D grade. “We’re in a crisis situation with the condition of dams and levees in the U.S.,” Nicholson explains. “There are more than 70,000 dams in the country, and many are beyond their design life. Unfortunately, it takes a big failure like New Orleans to get people to notice it.”

Pierre Home-Douglas is a freelance writer based in Montreal.