I mentioned to a few of you that I am the first geotechnical engineer that Build Change has hired. Other ex-pat engineers are structural engineers and construction trainers. Needless to say, they had saved several things in anticipation of my arrival.
Beginning shortly after the earthquake, the MTPTC (equivalent of Public Works Dept) undertook the task of assessing each structure in the Port au Prince area. Structures were then tagged green, yellow, or red. Green tagged structures had minimal damage and were sound enough to occupy. Yellow tagged structures had moderate damage requiring repairs, but were still considered sound enough to occupy (though you might be missing a wall or two). Red tagged homes were basically considered a total loss and could not be occupied. It is interesting to drive around town and see the tags spray painted on all the gates or near all doors.
Build Change, with other non-profit organizations serving as a funding source, has gone into some of these communities and conducted detailed assessments of these homes to establish specific retrofit solutions for each of these homes. We currently have a staff of approximately 60 national (Haitian) engineers who conduct these assessments, perform the designs, and then perform construction inspection. Our goal is to perform 40 assessments each week, but in the coming weeks we will be doing 2 to 3 times that many assessment per week.
Many communties of Port au Prince are built on steep slopes, one home on top of another. Rubble stone masonry retaining walls are used extensively for foundation walls and to create level building pads. The gross majority of these retaining walls were saved for me to analyze. There was a backlog of over 100 walls when I arrived, somewhat of a daunting task. I have thinned the stack a bit. To help get through the stack more efficiently I have developed a condensed version of the Federal Lands Highway (FLH) retaining wall inventory. I will be training our engineering staff later this week on the inventory program, in hopes that they will be able to sufficiently review and assess retaining walls. It has been a very satisfying feeling knowing that the inventory program that was developed by FLH thousands of miles from here will be able to be used to help put Haiti back on its feet.
As I mentioned, rubble stone masonry walls are about the only retaining walls I have seen here. The gross majority of them performed beautifully during the earthquake, with little or no damage. In fact, as I analyze these walls, in many cases I can't explain why they haven't failed. I suppose it has something to do with the care taken during construction, akin to many of the CCC era retaining wall that we see within the National Park System. The just don't build walls like that anymore.
While these walls did perform well I am certain that we will have to develop some retrofit solutions for many of the taller walls. There are a plethora of options available for such retrofits with proper materials, equipment, and construction expertise, none of which really reside in Haiti. The construction material of choice here is concrete. In fact, there isn't much else. Due to deforestation, timber isn't even available. I have begun to notice concrete telephone/electric poles around here (never seen that before). So as I begin to explore retrofit solutions, about all that I am left with is concrete, which is becoming a bit frustrating. There was a time in engineering history when concrete was all the rage and engineers didn't need materials other than concrete (there are still engineers that believe this). The engineering community has developed many more materials and techniques to solve problems, but concrete is still a very versatile tool. Unfortunately, it is the only tool in Haiti.
Beginning shortly after the earthquake, the MTPTC (equivalent of Public Works Dept) undertook the task of assessing each structure in the Port au Prince area. Structures were then tagged green, yellow, or red. Green tagged structures had minimal damage and were sound enough to occupy. Yellow tagged structures had moderate damage requiring repairs, but were still considered sound enough to occupy (though you might be missing a wall or two). Red tagged homes were basically considered a total loss and could not be occupied. It is interesting to drive around town and see the tags spray painted on all the gates or near all doors.
Build Change, with other non-profit organizations serving as a funding source, has gone into some of these communities and conducted detailed assessments of these homes to establish specific retrofit solutions for each of these homes. We currently have a staff of approximately 60 national (Haitian) engineers who conduct these assessments, perform the designs, and then perform construction inspection. Our goal is to perform 40 assessments each week, but in the coming weeks we will be doing 2 to 3 times that many assessment per week.
Many communties of Port au Prince are built on steep slopes, one home on top of another. Rubble stone masonry retaining walls are used extensively for foundation walls and to create level building pads. The gross majority of these retaining walls were saved for me to analyze. There was a backlog of over 100 walls when I arrived, somewhat of a daunting task. I have thinned the stack a bit. To help get through the stack more efficiently I have developed a condensed version of the Federal Lands Highway (FLH) retaining wall inventory. I will be training our engineering staff later this week on the inventory program, in hopes that they will be able to sufficiently review and assess retaining walls. It has been a very satisfying feeling knowing that the inventory program that was developed by FLH thousands of miles from here will be able to be used to help put Haiti back on its feet.
As I mentioned, rubble stone masonry walls are about the only retaining walls I have seen here. The gross majority of them performed beautifully during the earthquake, with little or no damage. In fact, as I analyze these walls, in many cases I can't explain why they haven't failed. I suppose it has something to do with the care taken during construction, akin to many of the CCC era retaining wall that we see within the National Park System. The just don't build walls like that anymore.
While these walls did perform well I am certain that we will have to develop some retrofit solutions for many of the taller walls. There are a plethora of options available for such retrofits with proper materials, equipment, and construction expertise, none of which really reside in Haiti. The construction material of choice here is concrete. In fact, there isn't much else. Due to deforestation, timber isn't even available. I have begun to notice concrete telephone/electric poles around here (never seen that before). So as I begin to explore retrofit solutions, about all that I am left with is concrete, which is becoming a bit frustrating. There was a time in engineering history when concrete was all the rage and engineers didn't need materials other than concrete (there are still engineers that believe this). The engineering community has developed many more materials and techniques to solve problems, but concrete is still a very versatile tool. Unfortunately, it is the only tool in Haiti.
It's nice that you have that expertise and can help them out. I'm sure they are very grateful.
ReplyDeleteAs you know people are always looking to make a difference to their home and it becomes slightly difficult to decide where to begin. Some prefer to work on the infra structure of the home, where as there are others that prefer to make a difference to their home by working on the landscaping of the home.
ReplyDeleteRetaining Walls Canton