compaction standards
compaction standards
(OP)
Could anyone tell me the protocol for building a home with a slab foundation over a former creek? A developer placed fill into a 10' deep trench and built homes on top. I am trying to find out if it was done properly, since all of these homes now are experiencing foundation problems ten years later. Is there a certain standard of compaction that must be met? Are there a required soil density readings that are kept on record? Who generally governs this process--- is it part of city code, or is it internally regulated by the design engineer? Thanks for your help.






RE: compaction standards
RE: compaction standards
The developer and his grading contractor should have done some quality control testing of the fill material and densities during construction. This would have been done by a soils testing firm, supervised by a geotechnical engineer. The testing reports should be on file at the engineer's office and with the developer.
the city or county should have also reviewed the plans, issued a grading permit to the builder and done inspections. contact them and have them review the permit file for the properties.
RE: compaction standards
RE: compaction standards
the city performs a review and inspection but it really is up to the designer to give the correct recommendations and to the contractor to do a quality job and the city is only there to make sure some minimum requirements are met.
In general, you are correct that fill is generally placed in shallow layers and compacted. But as indicated by civilperson previously, there are other issues to consider which should have been investigated during the design.
You really need to get an engineer to assist you with your investigation who is familiar with the soils, construction methods and city criteria in your area to help you discover what went wrong.
Also, are you sure the problem is with fill compaction? It could also be a problem with drainage, groundwater, collapsible soils in the subgrade, ground fissures or with the structural design of your building foundation slabs. I'm not sure I would want a concrete slab foundation on this site. Perhaps piles or a post tensioned slab would have been a better choice by the designer and could have handled settlement of the fill better.
RE: compaction standards
RE: compaction standards
RE: compaction standards
Or is it for a suit against the builder/contractor or to prevent the development of another area that the existing owners see as an asset and do not want to de developed?
Obviously, the engineering of the new site will depend on the site conditions and the previous site requirements may not be applicable. The records and inspection will depend on the design and construction methods employed for the new site/project.
Dick