I also just skimmed the discussion, but I can offer two pieces of advice based on my experience with two very interesting projects involving soft clay soils (Route 1/I495 interchange on the D.C. Beltway and Craney Island in Portsmouth, VA).
1) If you have soft soil conditions and are building...
Facca,
I agree with the statements of the two above. I've been involved with MSE wall design for nearly 10 years in both the public and private sectors. Based on what I have observed it is rare to find a wall designer who will take responsibility for external (global) stability. I interpret the...
Just to add to the above statements, we have seen lime/soil mixtures hydrate at temperatures above 140 degrees F with only soil moisture. If the pipes were leaking (before or as a result of the loading caused by the stockpiled lime) and more of the quicklime reacted, I suspect temperatures could...
If you do in fact have a loose condition that cannot be reached with conventional DDC, I suggest two other methods that could be more economical that compaction grouting: vibrofloat/densification and explosive compaction. Both of these can treat relatively large areas fairly quickly and be...
I tend to agree with VAD. Pavements can be designed for poor subgrade support characteristics (CBR values less than 1) by using adequate thicknesses of stone subbase and asphaltic base in conjunction with subgrade reinforcement with grids (bi-axial). The more interesting aspect of the problem...
You are indeed speaking of a large cage. Based on our recent experiences with some concentric cages up to 84" in diameter and 115 feet long, I have two comments. 1) More than 5 pick points and a good crane operator(s) are a must. 2) using an internal "mandrel" to help the pick is...
Just to provide a little experience we had and a word of caution. Make sure your source ash isn't susceptible to shrink-swell. Certain ashes, depending on the processes which they are produced should be used with great caution. To the best of my recollection, fluidized bed ash is one of the...
Interesting, interesting, interesting...We are indeed getting a lot of good discussion out of this one. Just thought I'd throw out some more fodder.
Many individuals subscribe to settlement estimates using DMT data (an undrained modulus value in low permeability soils and a drained modulus in...
Cmorgh,
(To leave no stone unturned)...Most of my experience is indeed with saturated clays, or those that may potentially undergo saturation over the life of a design. I have, however, run tests at the natural moisture content of the soil (at least what we thought the moiture content was) for...
I apologize if my words were interpreted as aggressive or diffinitive (although there was little ambiguity from the aggressive side). As was pointed out by the last set of posts, we can offer our advice, but by no means should it ever be considered "the answer." I have and continue to...
The basic soil procedure is ASTM D2435, which actually does mention our topics of discussion (Sections 5.5 and 11.3). If you are operating an AASHTO accredited or COE certified lab, this is also your standard for 1-D consolidation. Zdinak
I agree to the possibility pointed out by Focht3. However, I believe the impact of negative pore pressure in a consolidation sample will typically be low considering the typical way such specimens are collected, extruded, and trimmed into the ring as applied to 99% of all consulting projects. I...
In a sarcastic voice, complete a random variable study. Completing FVS in peat is risky business and is hit or miss. Unfortunately, you won't know whether you have a hit or miss. Also watch out for shells in soft marine clays, they can often skew results to the point of chaos. Zdinak
It is likely a feasible approach provided the compression parameters you are using were obtained using a consolidation specimen what was not inundated during testing (to model the field conditions). Using Terzaghi's 1-D approach is not exactly applicable since it was derived using a saturated...
Ashjun,
As has been said by the other posters here, your value is not atypical. In fact, if you did not get a number greater than 100 it would be suspect. I'm sure you are aware of this, but if you are not, the CBR value is a ratio of a measured resistance compared to the reference resistance...
