Cockrell School Engineers Address Haiti and Chile Needs
- Wednesday, Feb 17, 2010
Civil engineering faculty and their graduate students traveled to Haiti to assess damage, collect data and comfort locals. News outlets carried the faculty's Haiti lessons to aid Chile recovery efforts.
After the devastating earthquake in Haiti, the children of the Louverture Cleary School were too scared to return to their classrooms and dorms. Days had passed and they were still sleeping outside, fearful that an aftershock or tremor would collapse the buildings around them.
Patrick Moynihan, the school’s director, sought help from Dr. Wassim Ghannoum, an assistant professor in civil engineering. Moynihan emailed photos of the buildings to Ghannoum so he could make a preliminary determination of their safety. Ghannoum, whose research focuses on earthquake engineering and the collapse of reinforced concrete structures, judged the school’s buildings safe enough to use, pending further inspection.
But the children were still too frightened to return indoors.
Help was soon on the way, however, as a group of engineers, including Ghannoum, headed to Haiti. This relief effort, under mandate from the United Nations, was mounted by the Appropriate Infrastructure Development Group and the Multidisciplinary Center for Earthquake Engineering Research, organizations which had appealed for structural engineers fluent in French to go to Haiti and assess the safety of key surviving buildings.
Upon arriving in Port-au-Prince, they met school representatives and proceeded to the site.
“We inspected all the school’s buildings that evening before we could stay in them, and then we stayed in their worst building,” Ghannoum said. “We did this to reassure the students, many of whom had lost family members, that it was safe to go back in the buildings. That night they all slept inside and even though we had a minor aftershock the children did not panic.”
That was the beginning of a week-long effort by a team of 10, which included both engineers with earthquake expertise as well as Haitian-born engineers familiar with local logistics. Using standards set by the Applied Technology Council, they spent 10-30 minutes performing initial evaluations of approximately 115 buildings, labeling them green (safe), yellow (safe with restrictions) or red (unsafe).
They focused on essential infrastructure – hospitals, government buildings, telecommunications centers – that were necessary to get recovery efforts organized and functioning and the Haitian government operational again. While more in depth assessments will be required, this initial evaluation was a critical first step toward getting people back to work.
“The main difficulty was that we did not know what was inside the concrete,” said Ghannoum. “The amount of steel reinforcement is critical. We worked on the assumption that there was practically no steel...That was the challenge, working blind, so I always assumed the worst case.”
As he went from building to building, what Ghannoum could see was not encouraging.
“We saw the worst case scenario in substandard construction,” Ghannoum said. “Usually we use deformed steel bars in concrete, which helps them bond to the concrete. Most of the bars we saw, maybe 80 percent, were smooth so they just slid through the concrete. There was practically no confining steel to keep the concrete intact during shaking. The concrete itself was very sandy, with very little cement. We could crumble the concrete with our hands.”
The geography and geology of the Port-au-Prince area also worked against the city’s residents. A major fault line, the Enriquillo-Plantain Garden Fault, lies not far from Port-au-Prince. Many of the hardest hit areas of the city were built on soft coastal deposits and artificial land fill, which are particularly vulnerable to ground shaking.
Ellen Rathje, another civil engineering professor with the Cockrell School of Engineering, led a team of engineers and scientists who examined the damaged areas to understand the relationship between the area’s geology and the damage wrought by the quake.
“Each earthquake represents a living laboratory in which we can better understand how infrastructure withstands earthquake shaking,” Rathje said. “As a geotechnical engineer, I am interested in ground failure due to soil liquefaction, the relationship between soil conditions and enhanced ground shaking and damage, the influence of fault rupture on overlying infrastructure, and the generation of landslides due to ground shaking.”
Rathje and her associates used aerial photography, digital photos and GPS devices to document the location and extent of the damage. They also used a cone penetration device and surface wave testing to measure soil properties.
“Time is a factor because weather or clearing of debris can remove evidence of what actually happened during the earthquake,” she said. “Developing the appropriate interpretations of what happened requires documentation of the effects as soon after the earthquake as possible.”
Rathje’s team will use the information gathered to determine which areas are particularly vulnerable to earthquakes, which will help guide reconstruction to minimize the impact of future quakes. She was later interviewed by national Fox television reporter Shepherd Smith to compare the differences between the earthquakes in Haiti and Chile and guide viewers on appropriate aid responses.
Despite the smaller scale damage to Chile in comparison to the Haiti destruction, Chile needs immediate help with "critical facilities like hospitals..to treat those who are injured," she said during the Studio B live interview. "And critical infrastructure to get around such as bridges.. and overpasses. Those are called critical lifelines and we're always concerned with those as earthquake engineers because they are the bottlenecks to getting rescue and response efforts in."
According to Ghannoum, much work remains in Haiti. The extent of the destruction in Port-au-Prince was due in large part to poor construction methods and quality control, which points to one of the many challenges in rebuilding.
“You can make concrete construction seismically resistant – this is not inherently difficult – but it costs more and requires seismic design expertise,” Ghannoum said. “Haiti has no structural design codes and its engineers do not have the necessary expertise. We could not find any accreditation system for engineers like here in the United States. So any reconstruction effort in which local engineers would participate will require implementing design codes and educating Haitian civil engineers in using them.”
While training local Haitian engineers is a laudable goal, the situation is complicated by the number of nations and organizations participating in the relief and reconstruction effort. The World Bank, International Monetary Fund and United Nations, among others, will want to ensure that any construction they fund meets acceptable standards. With many offering advice, and a severely weakened Haitian government trying to act as arbiter, determining what type of building codes should be adopted, and then enforcing them, could be problematic.
“The IBC code we use in the United States is quite an advanced code and it would probably take a year to train local civil engineers to use it,” Ghannoum said. “We are faced with the following dilemma: do you put in a first-world design code requirement? If so, everything has to be designed by outside engineers and local engineers will have a very hard time participating. Or do you offer a simplified code that can be taught to local engineers in a relatively short time period?”
With so much work to be done, the latter approach might offer a way to get Haitian engineers involved in the reconstruction more quickly.
“One way is to give them really basic design rules,” Ghannoum said. “Do these simple steps: use proper material, steel and concrete; provide enough confinement for columns by adding more confining steel; add some lateral load systems, like shear walls; make sure you have continuity of steel. If you do these four steps – theoretically simple steps to take – you will have far fewer problems.”
The earthquake was a significant setback for Haiti, but there is hope that the sheer magnitude of this disaster will lead to changes that will benefit Haitians in the future. By offering their assistance and engineering expertise, Ghannoum and Rathje, as well as many other members of the engineering community, aim to help Haitians recover and build a stronger, more resilient Haiti.
Rathje's work at UT is supported by the J. Neils Thompson Centennial Teaching Fellowship in Civil Engineering which was established by the W.S. Bellows Construction Company.
NEW: Watch Ellen Rathje's interview with FOX's Shepard Smith about the recent massive quakes in Chile and Haiti at the Fox News site.
Visit the Cockrell School's Youtube site to watch Ellen Rathje's interview with KEYE.