posted on Dec, 1 2009 @ 12:55 PM
when you are building anything like a runway or a roadway you have to be able to get a certain amount of compaction out of the soil you are using for
the base of it. it could very well be that the soil in the area did not have the compaction they needed. the particles could have been to round to get
the stability needed.
If the soild at the site had to much clay or silt in it they would have to bring in some with more sand and gravel content to it.