Degenkolb Reconnaissance Team in Haiti – Day 5
Day 5
Highlights:
1. The seismic performance of the buildings constructed with the gingerbread architectural style continues to amaze. We studied four adjacent buildings, of which one was a house of the gingerbread style, and the gingerbread house was the only one standing or habitable.
2. The Portail St. Joseph area had frequent failures of brick URM’s. This is the greatest concentration of brick URM’s that we have seen so far.
3. One wheel barrow of recycled rebar = 40 goude or $1 US
4. Rain has come; hopefully it will not be back soon.
“A Taste of Gingerbread Style”
The morning started with an effort to coordinate with Peter Haas of AIDG (www.aidg.org). The original plan was to conduct some field surveys before heading over to Matthew 25, the base for AIDG in Port-au-Prince, to meet up with a new crew of engineers coming in from the States.Unfortunately, the plan fell apart and most of the morning was spent by the team arranging details and making calls. With the organizing work out of the way, we packed up and headed out near mid-day to complete some field investigations.
Our first area of interest was a stretch of four consecutive buildings on the south side of Rue St. Cyr. The buildings were of special interest to us in that they were representative of the four different building types in Haiti and were in immediate proximity of each other. The four buildings from east to west were the following:
- Building 1: CMU and brick additions to a Gingerbread
- Building 2: Gingerbread (See the blog for Day 1 as well as the discussion below)
- Building 3: A brick URM with wood framed floors
- Building 4: Concrete frame with masonry infills
Building 1 was a family residence. A two story structure, the original building appeared to be of the gingerbread architectural style. It appeared that a series of brick URM and CMU URM additions had been made to the original structure though we were unable to confirm this observation. The additions were sufficiently old so that some bars had corroded. The additions fared poorly during the earthquake especially the room and entrance veranda at the northwest corner. These additions appeared to pull away from the original wood framed building and then collapsed, blocking egress from the house to the west. There were some significant life-safety falling hazards and the northwest corner of the “gingerbread” portion of the house was not very stable. Brick was also used for the infill of the gingerbread and had fallen in some locations.
Building 1 front elevation (above)
Building 2 was a classic house of the gingerbread architectural style. Note that the gingerbread architectural style appears very similar to the “colombage” architecture common to some European alpine regions. Based on an observation of the minor damage to the building, the house appears to have performed without a problem. The infill likely provided initial elastic stiffness and as it degraded, the wood diagonals and the horizontal wood sheathing provided more than enough additional lateral capacity.
Building 2 southwest elevation (above)
Some damage was observed in the mud cement plaster with some portions of the infill falling off the wall and some minor spalls. The minor spalls clued us in on a small detail to the construction of the house. Nails had been added to the wood diagonals and vertical studs at the ends of the members that stuck out into the infill similar to a headed stud in concrete. The nails appear to have helped to keep the infill in place longer.
Building 2 infill restraining nails in stud and diagonal (above)
Building 2 infill restraining nail in stud (above)
The only significant crack observed in the building was a small bathroom brick URM addition to the house on the southeast corner. The crack had opened up approximately 2 inches in an east-west direction. It appeared that only the south wall of the bathroom was permanently displaced; the rest of the building seemed to be relatively untouched except for the previously described damage to the infill.
Building 2 crack in bathroom addition (above)
Of great interest to us was the owner’s description of the earthquake and the performance of his house. The house had performed admirably. The three people in the house at the time of the earthquake had not been knocked off their feet. None of the contents had even fallen off the shelves including glassware and some glass lamps. Based on the evidence of movement in the east-west direction, these contents would have fallen if the actual ground motion at this location had been of a great magnitude.
Building 2 contents on shelf (above)
Mark thanking the Building 2 owner (above)
Building 3 (brick URM) and Building 4 (CMU URM) were interesting but of limited value. Building 3 was a restaurant while Building 4 was a hotel. They both had collapsed and anyone inside each structure would have likely been seriously hurt if not killed. Despite our efforts to recreate the structures from the evidence available, we had limited success. We observed some poor detailing at some of the beam / column joints and some precast columns. We had heard that some columns are precast and then delivered on site and it appeared that some of the decorative columns were of this construction. Since these two building types have been discussed previously, we will refer you to the other blog entries rather than representing those observations.
Building 3 in foreground, Building 2 in background (above)
Building 4 Former 2 story hotel (above)
After completing our investigation on Rue St. Cyr, we jumped into our trusty Toyota minivan (see the blog for Day 4) and headed over to the Portail St Joseph area. This area is located immediately east of the port, north of the US Embassy, and west of the Notre Dame Catholic Cathedral. We had noticed previously when looking north from far down Grand Rue that this area appeared to be heavily damaged. Entering the area, we found building after building that had fared very poorly in the Jan. 12 earthquake. We also found the area completely congested with people buying and selling anything and everything despite only a portion of the buildings in the area standing or being habitable.
Portail St Joseph streetscape (above)
The buildings in the Portail St. Joseph area are often brick URM. Out-of-plane and in-plane failures appeared to be common. We observed several cases where the failure of one building may have triggered at least a local failure in the adjacent structure. With the buildings so closely spaced and even built immediately adjacent to either, it is likely that such failures could occur. We stopped and looked at several buildings including a functioning hospital, a school where one of three buildings had collapsed, and an orphanage where three of five buildings had collapsed. Amazingly enough, the orphanage had not suffered a single fatality despite the failure of three of their buildings.
Multi-story brick URM failure (above)
Mike doing a drop test of a CMU piece in Portail St Joseph (above)
One of the remaining buildings at the orphanage caught our eye. Some reinforcement was observed protruding from the brick where some appendages had fallen away from the main structure. On closer examination, it appeared that a double wythe wall had been used and some reinforcement included. The building performed adequately though the east face was significantly damaged with “X” cracking in multiple piers. The orphanage is currently not using the building.
East elevation of the orphanage showing cracking in brick (above)
One burning question for me has been how much money one can expect to earn recovering rebar from collapsed structures. We have seen men, women, and children trying to remove the rebar from the collapsed structures sometimes with nothing more than a hacksaw. While walking around the school, we met a young man with a wheelbarrow of rebar. The young man indicated to us that he was expecting to earn around 40 gourde (or approximately $1 US) for the rebar but needed to find a buyer. We declined but wished him good luck before heading on our way.
Finding out the price of recycled rebar (above)
At approximately the intersection of Ave Marie and Rue des Miracles, we came across something straight from Paris; the Marche de Fer. This market is housed in an iron structure that was originally destined in the 19th century to be the main hall at the train station in Cairo but ended up becoming a central hub in downtown Port-au-Prince. And the area was completely filled with people. We were the only ones crazy enough to even try to take a vehicle through the area. Given the mass of people and the environment, we were unable to depart from the vehicle and see how the Marche de Fer performed. It appeared that there may have been some damage but we will try to get back if possible to complete a more detailed observation.
Marche de Fer (above)
As we were heading back to the hotel for the night, we drove by Hotel Nova Scotia (see the blog from Day 2). This structure continues to intrigue us. As we drove past, we noticed that the Ministry of Public Works, Transportation, and Telecommunication (MTPTC is the French acronym) has red-tagged the building and slated it for demolition. We will be looking into this a bit further over our last few days here in Port-au-Prince.
Hopefully we do not have any more rain. Once we were back in the hotel, the rain started falling. Though the shower was not too long, it served as a reminder of the importance to get people back into their homes and out of the camps. Given our abilities and knowledge, we can continue to be part of the process to make that happen and we are looking forward to the opportunity. When the rains come and if people are still living in the tent cities, this humanitarian crisis will become even worse.
December 21st, 2010 at 12:11 pm
Bof, je suis d’accord mais il faut aussi dire.