Compaction
Compaction
(OP)
I have a client who has placed fill material and it initiall passed density and moisture requirements, but during installation of utilities it was noticed that the soil was dry. Now this most likely happened due to the dry weather. The testing firm is saying to scarify the soils to a depth of 12 inches, add water, and then recompact. The only problem is that utilities are in and doing so will most likely cause several utilities to be damaged. The standard Proctor has a optimum density of 104 pcf and moisture of 17% with a +3% and -2% spec window. The moisture samples obtained say the moisture content is 12%. From my conversations, only the top 12 inches is effected by the dry conditions. If left in place how much settlement if any could be expected. They are contemplating on putting a water truck on the subgrade and letting the water permeate into the ground. The soils are a silty loess material with a LL of 40 and a PI of 19. Thanks





RE: Compaction
RE: Compaction
f-d
¡papá gordo ain’t no madre flaca!
RE: Compaction
RE: Compaction
There are really two issues at play here: The behavior of fill when the moisture content changes AND the bahavior of fill under dynamic loading with various moisture contents. In static conditions, dry density is not affected by moisture content. In dynamic conditions it is - ALOT!
f-d
¡papá gordo ain’t no madre flaca!
RE: Compaction
RE: Compaction
Providing it's not "very hard" by virtue of dry strength. Do a density test and see whether it remains in spec.
f-d
¡papá gordo ain’t no madre flaca!
RE: Compaction
Regards,
Namdac
RE: Compaction
If the m/c is 5% low, you probably aren't getting compaction results much above 95%, which I assume is the minimum.
I'd evaluate it carefully. We've had soils that have "baked" during the summer months that look fine during proofrolling and meet the dry density requirements, but are out of spec for moisture. Then, when it rains, the soils go to hell in a hurry.
And yes, I just noticed I'm a month out on this.
RE: Compaction
I'm in Richmond, Virginia also. Honk next time you pass a brown station wagon with licence plate "fatt dad".
f-d
¡papá gordo ain’t no madre flaca!