Design Challenges

[WARNING: Engineering content. Prepare to feel nerdy.]

One of the ongoing projects that I have been working on since getting here in August is setting up some design spreadsheets in Excel to facilitate the design process here in the office. Since my project trip hasn't left for Gulu yet, I have been working more on this the last several days.

So far this has included creating design sheets for reinforced concrete beams and columns, wood trusses, concrete footings, and steel beams and columns (although the steel ones will probably hardly be used). All of these have been rather simple as design here is relatively straightforward with almost every building being single-story confined masonry construction.

Some of the challenges of designing in Uganda has to do with local construction practice. Since material is very expensive here, buildings will often be built without the necessary reinforcing steel or maybe even none at all! In extreme cases, people will leave out the concrete columns altogether and rely solely on unreinforced masonry. This is a very dangerous idea, especially in the event of an earthquake!

With all this in mind, we have to be very careful how we design. Since we know that only certain sizes of rebar are affordable (or even available) and construction workers will probably only make columns the size of the brick width (about 10in) even if the column is specified to be larger, we have to design knowing that it may not be built according to our specifications.

I should clarify that not all buildings are poorly constructed or purposely not built to the design (in fact, most are not). But knowing that it does happen occasionally is reason enough to more forward with caution while designing here in Uganda.

One thing that scares me is the potential for a major earthquake in the area. Buildings here are sufficient to handle gravity loads, but in the event of a large earthquake many buildings would collapse and there would be much devastation. It's a frightening thought and I hope it won't take a major earthquake to get a wake up call.