Tuesday, January 4, 2011

September 23rd, 2008

Italy. Built on the edge of the job site, a tower crane collapsed into the home of three families destroying the home. In the two stories that I have found, neither notes anyone being injured. The cause of the accident is noted at a burst water pipe which then washed out the soils. A second story indicated that a soils engineer says that the  soil was not properly contained nor assessed.

Soils are often overlooked. Putting a crane on the edge of the hole requires that the bearing capacity be assessed. Non-native soils should also be a big red flag. Virtually every job uses a soils engineer, so what's the problem with having them assess where you are going to put the crane? Was cribbing, or matting, used to spread out the load under the pads? It's pretty straight forward that you should take advantage of spreading out the load at every opportunity. If you are putting the crane on the edge of the job site, you should consider reinforcing soils at least around the crane. Soils nails, sheet piling, lagging, air-placed concrete, CDF, etc. Find a way to slope the edge or secure the soil.

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