In calculating void ratio of soft soil slurry during 1-D consolidation in a large apparatus, what equation should be used? During testing, the deformation is measured from LVDT, but need to calculate the void ratio to plot void ratio-stress relationship. Is there any difference in the equation we know for large or small strain consolidation?
http://environment.uwe.ac.uk/geocal/SoilMech/consol/soilcons.htm
Independently of the small or large strain consolidation, if you have you have constrained boundary conditions like an oedometer, the void ratio SHALL be calculated if SATURATED as e=Gs x V / Wd - 1, where Gs is the density of solid particles, Vc is the corrected volume (therefore the Area of the apparatus x original height - displacement of the LVDT) and Wd is the dry weight of the specimen. if the soil is not saturated then you should use e=Gs x (1+w) / (W/V) - 1, where W is the total weight of the soil and w is the % of water content
@Shriful Islam
Asalaam aleikum: The answer to your question is as follows: By definition the average degree of consolidation of one-D considation at time t is defined by U(Tv) = ∫ (1- u/uo)dz where Tv = Cvt/d2. where t = elapsed time; Tv = time factor as defined; d = effective drainage length. Now the settlement at time t (wt ) is related to the final settlement at time t = ∞ (wf) by w(t) = U(Tv)*wf. But it is well known that ΔH/Ho = Δe/(1+ eo). But w(t) = ΔH. Thus, it is easily found that the void ratio at any stage in one-D consolidation is given by e(t) = eo - Δe where Δe = ΔH*(1+eo)/Ho = w(t)*(1+eo)/Ho = U(Tv)*wf*(1+eo)/Ho. Ho = Initial clay thickness and eo = initial clay void ratio. Using the Cc method: wf = [Cc*Ho/(1+eo)]*log10(1 + Δσ/σ'o). I hope you will find this answer useful.
Dear friends,
I am a little disturbed by the kind of questions frequently posted. With all due respect Mr. Islam, these are questions for you to answer and perhaps then discuss with your tutor if something doesn't fit. Literature review is about exactly this, i.e. self teaching and digging into the literature and assessing what is suitable. If you expect others to solve problems instead of you, or even propose solution instead of you searching and assessing, then I am sorry but this is not research. More and more lately I find questions that show people attempting to circumvent this, I confess, arduous process of conquering the art of discovery. This is what Research has been all about since the days of the first Greek physical philosophers 7 centuries before Christ. I encourage you to discover knowledge by yourself. It is the ultimate academic achievement.
Regards
George Tsifoutidis
Engineering Geologist, BSc, MSc, PhD
Dear Islam
I do recommend you to use "phase diagram" and from it, you can easily calculate void ratio
Thanks all for your cooperation and suggestion. I have got the answer and hopefully it will work.
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