p>In a upcoming trial we have against Tower Hill some interesting engineering questions have come up. We have discussed the different types of repairs that can be performed on a home being affected by sinkhole activity. The standard technique is compaction grout which essentially pushes a concrete type material into the ground causing the soils to push out from the concrete and solidify. This method is only used to a depth of about 15 feet below the surface to avoid damaging the house. When you have loose soils at the surface they are not being remediated by the compaction grout because it is stopped before nearing the surface. The more commonly accepted technique for finishing off that surface area is chemical grout. It can be done near the surface with substantially less risk of damaging the home. In this case, everyone agrees that loose soils near the surface are a problem and something needs to be done to fix this problem. However, the engineer for the insurance company has a theory that when the compaction grout is performed, it will cause the soils below to not only displace outwards but also upwards and, in theory, this will unintentionally solidify those soils a the surface. We have dubbed this the vertical compaction theory. The problem is, this is not a widely accepted theory and there is little to no data to support it. To peform the chemical grout at this property would cost about another $17,000. Tower Hill says no so to trial we go.
October 13, 2012 by Morgan Barfield