Engineering Analysis Report (EAR)
Engineering Analysis Report (EAR)
(OP)
My firm has been requested to perform an EAR for an FDOT project.
Project Info: the contractor has installed 27 drainage structures and has no compaction data. Here in Florida, drainage structures are required to be backfilled in 6 inch lifts and compacted to 100% pf the standard proctor. Pipe backfill is required to be 95% of the standard.
I was thinking performing hand auger borings with DCP testing at 6 inch intervals im the structure backfill as well as in the pipe backfill, and comparing relative densities. This has been accepted by the FDOT on our past projects. However, the problem here may be the difference in compaction requirements (i.e. comparing material compacted to 95% with material that is supposed to be 100%). I don't think tubes or drive sleeves would work. SPT's may be more economical than DCP testing due to the amount of tests that will be required.
Anyone have any recommendations for alternatives? Contractor wants to avoid digging down in 6 inch increments and testing with a nuke gage if at all possible.
Project Info: the contractor has installed 27 drainage structures and has no compaction data. Here in Florida, drainage structures are required to be backfilled in 6 inch lifts and compacted to 100% pf the standard proctor. Pipe backfill is required to be 95% of the standard.
I was thinking performing hand auger borings with DCP testing at 6 inch intervals im the structure backfill as well as in the pipe backfill, and comparing relative densities. This has been accepted by the FDOT on our past projects. However, the problem here may be the difference in compaction requirements (i.e. comparing material compacted to 95% with material that is supposed to be 100%). I don't think tubes or drive sleeves would work. SPT's may be more economical than DCP testing due to the amount of tests that will be required.
Anyone have any recommendations for alternatives? Contractor wants to avoid digging down in 6 inch increments and testing with a nuke gage if at all possible.





RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
What method would you use to correlate the DCP results to relative density or MDD? I would interested to see the outcome of this, if you wouldnt mind sharing.
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
Unfortunately for the contractor, all of the storwater structure backfill has failed miserably with DCP blows of 3 to 5 on most everything we have tested.
As an alternative to digging around all 29 structures and replacing in 6 inch compacted lifts, I'm thinking some sort of grouting may be cheaper. Anyone use grouting for a project similar to this one? Of course it will ultimately be up to the DOT as to how the contractor corrects the deficiencies.
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)
What are your blows, blows per 50mm or blows per 100mm.
Not sure if grouting would be my first choice. Low mobility grout and the likes expand, could this damage the pipe due to the increse in pressure.
If not too deep it may be easier to excavate and recompact?
RE: Engineering Analysis Report (EAR)
RE: Engineering Analysis Report (EAR)