Consolidation Quiz
Consolidation Quiz
(OP)
How much will an embankment of clay fill (CH and CL mix) compacted to between 92% and 95% rel. compaction based on the max. dry unit weight of the ASTM D 698 method settle (consolidate) under its own weight? (in terms of a percentage of embankment height). Ignore foundation soil. Looking for long term total settlement (under centerline of wide embankment). Moisture content at time of compaction is say between optimum and +2%.
In the stormwater management pond industry I have seen requirements of 5% camber but I would like some better feedback.
Thanks!
In the stormwater management pond industry I have seen requirements of 5% camber but I would like some better feedback.
Thanks!





RE: Consolidation Quiz
But these 'shrinkage values' are based on "rules of thumb": I suggest that you monitor a few since the soil, weather, etc. all affect the resulting settlement.
RE: Consolidation Quiz
You will note that there are not a lot of responses to this question and it is not because it is not a good question.
RE: Consolidation Quiz
If I recall the references, I'll post them here -
RE: Consolidation Quiz
I am thinking about your query as it is, indeed, intriguing. Maybe with time, if I can get any, will permit me to look at this in more detail.
RE: Consolidation Quiz
Zdinak
RE: Consolidation Quiz
I saw your note - in another thread - referencing your question about minimum unit weights in an 'embankments' thread. I can't find your posted question.
Point this old dog in the right direction, and I'll try to help -
RE: Consolidation Quiz
I'm very interested in your question as it is the red line of my research work.
Though many researchs have been done on this wide subject, you should find interesting points in particular in the proceedings of a conference held in 1978, called "Clay fills" (Proceedings of the conference held at the institution of Civil engineers, London).
I have to say that your question need to be more precise because there can be a confusion between consolidation at constant water content and consolidation due to water content changes. Moreover, the height of the embankment is a key, in particuler in the case of water content changes because an increase of water content can also lead to a swelling behaviour.
P.S : one question for the experts of the site : I asked for informations about use of material containing organic matter in this forum and nobody seems to be interested in answering to me. Was my question inappropriate in this forum or completely irrelevant ????
RE: Consolidation Quiz
I missed your question on organics. Most of my projects don't encounter much - other than the top 3 to 6 inches of grass mat and the occasional tree root ball. I'm afraid that I won't be of much help.
Did you start a message thread? Point me to it - I'll see if I can help.
RE: Consolidation Quiz
Valfer: When I see your thread designation, I'll make a note to comment even if nothing more than to say
I know how it can be. My first post was on the "real" skinny on percentages of elongated and flaky particles in concrete and asphalt - we have a very tight spec here and the contractor can't/won't meet it. So, what kind of relaxation could we make. Got NO REPLIES !!
RE: Consolidation Quiz
Thanks for your answers. I had never been on the "Eartwork and grading engineering" forum but I'm going to try my question again over there. My thread here was Thread274-42324.
RE: Consolidation Quiz
RE: Consolidation Quiz
Settlement occurs during construction from compression of air in the voids I think, so that there is little opportunity for post-construction settlement. On soft foundations, this would obviously not be the case.
RE: Consolidation Quiz
Keep in mind that two factors - time and water - affect whether a given fill will experience all of its settlement potential at a given point in time.
And your comments make another important point: variability in performance of compacted fills should always be expected. I was taught to plan for the worst - not pray for the best.
RE: Consolidation Quiz
RE: Consolidation Quiz
Together, the U.S. Army Corps of Engineers and the Bureau of Reclamation Division of the U.S. Department of the Interior have probably built more dams than any other organization. Their collective review of their many observations form the basis of my comments. Nothing personal, but their dam experience is "bigger" than yours - particularly since all you have really said so far is that they're wrong, yet you haven't given us anything to use in evaluating your claim!
I am interested in your experience, though. Please describe where the dams were built, the materials used, type of impoundment, embankment height, and when you measured the settlement. Please share with us!
RE: Consolidation Quiz
I performed the testing on embankment fill for a retention pond in Burlington and passed them with a minimum 92% in all areas. The following year, I found myself being sent back to the same location. I tested the fill at 82-88% compaction with failure in some areas. It was so bad, I had trouble unsticking my boots from the fill as I walked. My thinking is that if any amount of money is being spent on your operation, it may be prudent to revisit the possibilities of avoiding the use of compacted clay. I enjoy testing compaction that is increacing as time goes by, instead of going the other way...
Best of luck.