Please refer to my earlier post if you have not read it. The main thing that causes buildings to fall down is lack of shear walls. Some information suggests that the major movement of the Haiti quake may have been up and down rather than side to side. Shear wall’s main advantage is protection from side forces. Also, an 7.0 quake anywhere is a pretty big one. Then there were other problems such as too little cement (the expensive component) in the concrete and too little steel reinforcement.

OK, make that steel reinforced shear walls made with real concrete. Still, my feeling is that loss of life would have been cut in half, in the Haiti quake if shear walls had been present. If in the near future some engineer states that life loss would have been ten percent or less I would not be surprised. I hope to see some analyses coming out of the disaster in the future that will show this more accurately.

Imagine a Haiti where the buildings in the port, airport, police stations, hotels, government buildings were damaged but not collapsed. We’d have a hundred thousand or so more people to worry about feeding, but we could all live with that. The time is coming very soon when the worry and effort will be on rebuilding. Any aid to that effect must have structural requirement strings attached. We need a force of UN building inspectors to come in after these disasters. Whatever it costs will be saved in the long run.

Some places like Haiti are earthquake prone. Others like Nang Rong are not. Still, since it is so inexpensive to do so, shear walls should be used in all concrete construction.

This may sound like an advertisement, but if you have anything to do with a building project anywhere in the world remember the name “shear wall”. Ask for them by name. Accept no substitute.

Almost two weeks ago I noticed a new building starting just around the corner from me in Nang Rong. I know, I say everything is just around the corner. It usually is. I live close to city center, such as it is. My house is on the same street just beyond the houses your see rising in the background in these pictures.

The rebar runs up pretty high, so I’m guessing it will be a two story building like those around it. I want to see how it goes up, but from the start it appears to have a problem. In the first picture there is no rebar placed between any of the narrow columns, and no concrete poured between them in the second picture. Such walls, if present, would be called shear walls. They may be engineered or not, have enough rebar or not, but they would still be shear walls.

Shear walls prevent the columns simply bending over due to a side thrust from an earthquake. When this happens the concrete floors and roofs above “pan cake” down on whoever is below. It can get really bad if it is a school and in session. That happened not long ago in China.

You can read about shear wall basics here.

I see buildings built like this all the time in India. Only in one case of an under construction building (large Catholic home for street boys – Yay!) do I remember seeing steps taken to prevent pan caking. I talked to an Indian geologist about this and his answer was “We don’t have earthquakes in this city.” This was after he told me about an earthquake that killed 30,000 people years before about 800 miles south of where we were.

Earthquakes can happen anywhere, although they may be less likely in some places, such as Nang Rong. If one does happen what then? If this current building were built correctly, it could hold itself up in an earthquake, and maybe also help stabilize buildings around it.

You may have heard about how expensive it is to fix an existing building for earthquake resistance, but shear walls are very cheap to put into a new building. The builders of this Nang Rong building are going to fill some of the spaces between the pillars with brick anyway. To fill a few of these places with concrete and a bit of rebar instead would cost very little more.

This is important! Even if built badly, without an engineer, buildings with shear walls don’t fall down. They may crack or be damaged in an earthquake, especially if engineered badly or not at all, but they just don’t fall down. The people in them survive.

In any of the buildings we build in Opportunity Village, if there is concrete over your head, there will be shear walls, guaranteed. We’ll even go one step further and properly engineer them!