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On Jan. 12, 2010, a magnitude 7.0 earthquake struck the southwestern corner of the island of Hispanola, devastating the poorest nation in the western hemisphere. The epicenter of the Haitian earthquake was located approximately 15 miles west of Port-Au-Prince, near the town of Léogâne. Approximately 220,000 people died as a result of the earthquake, more than 180,000 homes were damaged, according to the United States Geological Survey (USGS), and approximately 1.5 million people were left homeless.

Map of Haiti.
Simpson Gumpertz & Heger Inc.

Comparing the Haiti event to the 8.8 magnitude earthquake that shook Chile in February 2010, in which approximately 600 people died, and the 9.0 magnitude earthquake and ensuing tsunami that hit Japan in March 2011, in which approximately 15,000 people died, it is clear that the lack of seismic-resistant construction was a major contributor to the loss of life.

Getting involved
Before Haiti became associated with devastating earthquakes, Paul Fallon, a Boston-area architect with TRO Jung|Brannen, Inc., was involved in designing a healthcare clinic for a medical group, Forward in Health (FIH), near the Haitian city of Les Cayes, located approximately 100 miles west of Port-Au-Prince. At the time the earthquake struck, the clinic’s site walls and building foundations were already complete. Although Les Cayes was spared from the devastating damage, Fallon immediately realized that the FIH group needed to consult with a structural engineer with expertise in seismic design to review the proposed clinic building. He contacted Associate Principal John Thomsen from national engineering firm Simpson Gumpertz & Heger Inc. (SGH) for advice on how to make the proposed design more earthquake resistant.


Forward in Health clinic foundation consisting of rubble stones with CIP concrete floor slabs. 
Forward in Health

Within a few months of the earthquake, Fallon and SGH became involved in two other significant projects: the Be Like Brit orphanage and the Mission of Hope School, both located in Grand Goâve only 15 miles west of the Jan. 12, 2010, epicenter. The Be Like Brit orphanage is being built by the Gengel family of Rutland, Mass., in memory of Britney Gengel who perished in the Haiti earthquake while on a community service trip with her college classmates. The two-story-tall orphanage is in the shape of a “B,” commemorating Britney, and eventually will house 66 children. The Mission of Hope School will be a three-story school building and will house classrooms for as many as 600 children. This new school building will replace several existing buildings that were damaged severely during the earthquake.

SGH made the commitment to provide structural engineering design services for all three projects on a pro bono basis, and has worked with Fallon and other volunteers from TRO Jung|Brannen to make these projects a reality.



Seismic codes and design in Haiti
Prior to the January 2010 earthquake, seismically resistant design and construction were relatively non-existent in Haiti. After agreeing to help with these three projects, SGH researched building codes and standards applicable to Haiti and discovered that Haiti does not have an official building code or standards to ensure construction quality. Additionally, other than the information from the Global Seismic Hazard Assessment Program, there was limited information available for seismic design criteria for Haiti. The information that was available did not remotely represent the seismic potential witnessed in January 2010.

During the months following the earthquake, the USGS published a report containing seismic-hazard maps with peak ground accelerations for Haiti. This report became the basis for determining the seismic demands for these three projects.

Construction types in Haiti
Like most underdeveloped countries in the world, construction types in Haiti are driven primarily by the availability and cost of construction materials. Concrete is the most readily available, lowest cost construction material in Haiti. Although there are some examples of steel and wood construction, availability and cost of these materials makes their use much less common than concrete.

 

Step-by-step sequence for constructing a reinforced masonry infill wall with CIP concrete columns.
Simpson Gumpertz & Heger Inc.

 

One of the most common Haitian construction types consists of stone rubble foundations, locked together with a reinforced cast-in-place (CIP) concrete slab-on-grade, CIP concrete columns and perimeter beams, with unreinforced concrete masonry unit (CMU) infill walls, and CIP concrete elevated floor slabs. This construction type is similar to a system used in many countries around the world, known as confined masonry construction. While confined masonry systems are used throughout the world, these systems performed poorly in the Haiti earthquake. In Haiti, most confined masonry systems have minimally reinforced concrete columns and beams, and predominantly unreinforced masonry infill walls. As a result, these systems are relatively heavy and have little to no ductility. This combination of heavy mass and poor ductility led to the widespread brittle, abrupt failures seen across Haiti during the earthquake.   
In addition to the undesirable balance of mass and ductility, the strength of masonry and concrete is much lower than we would expect in the United States or other developed nations. Furthermore, the steel reinforcement often consists of smooth bars with inadequate lap splices and development lengths.
Design challenges
The most readily available construction materials in Haiti are CIP concrete, CMU blocks, and steel reinforcement. Consequently, we must utilize these materials, and the local labor force, to design and construct seismically resistant structures that will perform well during the next earthquake. To better understand the common practices and limitations of construction in Haiti, SGH spent several hours in meetings in its Waltham, Mass., office with Haitians that have significant construction experience in Haiti. During these meetings, the team was stunned by several of the stories its Haitian counterparts shared about how they typically construct buildings there. Details as fundamental as providing steel reinforcement in infill masonry walls were typically left out of buildings. Most concrete is mixed directly on the ground by laborers using shovels to mix the coarse aggregate, sand, cement, and water and then conveyed with five gallon pails to the desired location. It was during these meetings that we truly realized that fundamental seismic-resistant practices common in the United States were unknown to the Haitians. 

 Rendering of a masonry wall during construction.
Simpson Gumpertz & Heger Inc.
One of the biggest overall challenges of our involvement in these projects was explaining to the Haitian labor force why certain structural details are important to the integrity and performance of the structure.
While all of SGH’s Haitian projects have been subject to these challenges, each project has its own unique challenges:
Forward in Health (FIH) clinic
The clinic was under construction when the earthquake struck. The traditional rubble foundations and cast-in-place (CIP) concrete slab on grade had already been cast when SGH was asked to assist. The only reinforcement tying into the foundation was for columns that would confine the unreinforced masonry infill walls. In the United States, retrofitting the foundation with adhesive dowels drilled and epoxied into the foundation would be a relatively easy task. However, in Haiti, epoxy adhesives were all but non-existent. After reaching out to a U.S. manufacturer of epoxy adhesives and explaining the circumstances that we were dealing with in Haiti, the manufacturer donated several boxes of epoxy adhesive and the tools necessary to install it. Doctors from FIH packaged the donated adhesive and tools into large duffle bags and transported them to the site. The project team used the donated materials to post-install vertical reinforcement into the foundation for all of the masonry infill walls. Engineers could then reinforce the masonry infill walls to act as lateral-load-resisting masonry shear walls, resulting in a much more ductile lateral system.



Be Like Brit (BLB) orphanage
The BLB orphanage is brand-new construction on a large, open site on the side of a mountain overlooking the Bay of Port-au-Prince. However, since the building is a memorial to a young woman who perished in the earthquake, the primary focus of the design team was to design a structure that would provide superior seismic performance during future earthquakes to protect the lives of the 66 Haitian children that would eventually call this building home. Fortunately, SGH got involved in the BLB orphanage project at the onset of the design phase giving the team more opportunities to collaborate with the project architects to develop a structural system that would provide superior seismic performance yet allow for a functional architectural layout for the orphanage. The structural design governed over the architectural design; therefore, the project architect gave the highest priority to our requests for lateral-load-resisting shear walls.

Mission of Hope (MOH) School
The Mission of Hope School is being built on a tight urban site in and around several existing buildings. The buildings that were damaged in the earthquake are being demolished; however, newer structures that survived the earthquake with only minor cosmetic cracks are being preserved. In addition, the site has a significant slope from back to front, and the close proximity of the new foundations to the existing foundations is dictating the shape and size of the new school footprint.

Construction techniques — The learning curve
During SGH’s involvement in these projects, we have set an overarching goal — to raise the bar for all of Haiti. Our objective is not just to design and build three seismically resistant buildings that will withstand the next earthquake, but also to design and build three buildings that will become a standard for other new construction in Haiti. In order to achieve this goal, the buildings have to be constructed using predominantly local labor, who not only construct these buildings properly, but understand the importance of why they are designed and built in this manner.
CMU walls being constructed on the first-floor level.
 Forward in Health
We are fortunate to have good communication among the Haitian members of our project teams. The construction foremen for the BLB orphanage and the MOH School are Haitian Americans who have visited our offices in Waltham, Mass., understand English, and can translate our concepts to the construction workers in Creole, their native language. Nonetheless, the traditional methods of documenting structural details that we are accustomed to in the United States are meaningless to people without a culture of using paper design drawings as a guide for construction.
In order to illustrate the structural concepts clearly and concisely, we developed a series of isometric diagrams and corresponding sections, titled “How to Build a Wall in Haiti in 35 Steps.” We used Revit Structure to model isometric details in each step to clearly illustrate how each piece fits together. The 35 isometric diagrams show the reinforcement placement, each concrete placement, and each lift of masonry construction over the height of a two-story-tall bearing wall assembly (Figure 2 shows a typical step in the sequence; Figure 3 shows a rendering of a typical step in the sequence). While the SGH team would never consider going into this much detail for a project being built by an experienced contractor in the United States, it was paramount for the team to explain all of the steps and details to the Haitians learning this construction for the first time.
Even after explaining the wall construction step-by-step, getting the proper reinforcement size in the right locations with the proper spacing and with adequate lap splices and development lengths has been a challenge. Such attention to detail is not part of the Haitian construction practice. Even though we understand that good reinforcement detailing is essential for providing adequate ductility in reinforced concrete and reinforced masonry structural elements, these concepts are difficult to translate to people with limited experience with seismically resistant design and construction.  

Construction administration
At this time, all three projects are in some stage of construction. At the Forward in Health clinic, SGH has completed retrofitting the existing foundations with drilling and adhesive doweling vertical reinforcing bars for the masonry infill walls. Construction crews now are building the reinforced masonry walls that will define the first-floor clinic spaces.

 Be Like Brit foundation excavation is complete and reinforcement is being placed for casting foundations.
Be Like Brit

The excavation for the Be Like Brit orphanage started in January and now is complete. Crews are placing the reinforcement for the conventional spread and strip footings and concrete placement is scheduled to begin in May 2011. The foundation excavation was all hand dug. While an experienced excavator operator could have dug the foundations in a matter of days, the project manager for BLB, Len Gengel, insisted on employing Haitian men and women to dig the excavation for the foundations by hand to help the local economy. To date during construction, the BLB project has continually employed approximately 25 Haitian men and women.

The Mission of Hope School began demolition of the old damaged buildings and excavation of the project site in April. SGH is hopeful that the new building foundations will be cast in early summer 2011.

It is difficult for us, living in the United States, to understand how long construction takes in Haiti, but the obstacles are real and they are numerous. Be Like Brit has a 9,000-square-foot footprint arranged around two central courtyards within the B-shaped footprint of the building. There are more than 1,000 linear feet of strip wall footings (3 feet wide) that were dug by hand during the course of several months. Although it is possible to purchase CMU blocks from a local distributor in Haiti, it is more economical to make them onsite using special molds. The three-cell blocks they were fabricating on the Forward in Health site are typical in Haiti; however, they do not lend themselves to providing continuous vertical reinforcement. SGH had to make a special request to build molds for two-cell CMU blocks so that the cells would align for the vertical reinforcement in a running bond configuration. As rudimentary as this may seem, SGH’s construction is well above the local norms because both Forward in Health and Be Like Brit have purchased, stocked, and shipped panel trucks full of supplies and equipment from the United States to build their projects. The team is using laser transits to lay out the buildings and vibrators to consolidate the CIP concrete; tools that are foreign to the average Haitian construction worker.

Ensuring construction quality on projects thousands of miles away with language and technical barriers is an ongoing challenge. Thankfully, SGH can leverage technology to help its efforts. The Be Like Brit construction site, although it does not yet have any electrical service, has wireless Internet available. The site superintendents send the team progress photos on a regular basis, which they can mark up with comments, sketches, and notes, then e-mail back to them. SGH receives several cell phone calls per week from the site asking for clarification and direction. Skype also is available for times when a face-to-face discussion is desired even though the parties are thousands of miles apart.

The Mission of Hope School superintendent took videos of the buildings that were scheduled to be demolished and posted them on YouTube so the team could have a virtual tour while sitting at their desks in Waltham, Mass. 
SGH anticipates making site visits at key periods during construction; however, for now they are fortunate to leverage their technological tools to assist in construction administration to provide good quality assurance.
Conclusion
More than a year has passed since SGH began working on these three projects in Haiti: the Forward in Health clinic, the Be Like Brit orphanage, and the Mission of Hope School. Construction began on each of the projects and the team is hopeful completion will be within the next few years. SGH’s motivation to get involved was to help the people of Haiti by sharing their knowledge and expertise in seismically resistant structural design in the hopes that they will never again need to live through the devastation they experienced on Jan. 12, 2010.

                                                                                                 

John H. Thomsen, Ph.D., P.E., SECB, is an associate principal at Simpson Gumpertz & Heger Inc. (SGH). He can be contacted at jhthomsen@sgh.com. Brian M. Twomey, P.E., is a Staff II at SGH. He can be contacted at bmtwomey@sgh.com. Paul Fallon, RA, LEED AP, is a senior associate at TRO Jung Brannen, Inc. He can be contacted at pfallon@trojb.com.

To read the unabridged version of this article with images, visit www.gostructural.com

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