Questions tagged [soil-mechanics]
24 questions
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How does excess water makes soil compaction more difficult?
I understand how water content helps compaction, by being kind of a lubricant between the soil particles, that helps them slide into position. But I don´t really understand how it starts affecting negatively after surpassing the optimum water…
piguiligui
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Low pile capacity during pile driving
When driving piles, the resistance from the soil is constantly measured.
What happens when the expected resistance values from the soil are not obtained?
For a single pile or for multiple piles?
What do we do in that case?
upstream
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What is the effect of ageing on preconsolidation pressure?
Preconsolidation pressure is the maximum effective vertical overburden stress that a particular soil sample has sustained in the past.
How far in the past does the soil remember its loading/the pressure it sustained?
In other words, suppose that…
Bibek Panthi
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Is it possible for a silt soil to be compacted hard as a rock?
I had been told that a silt soil, when professionally compacted (from all the laboratory essays to the compaction with a vibratory roller), ends hard as a rock, and when hit with a metal bar it makes a metallic noise.
I find that hard to believe. Is…
numef
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Testing specimens by dropping a ball on them and counting the number of drops required before the collapse. A better way?
A huge number of specimens are built. For each specimen, soil is mixed with cement (and Zeolite) with different percentages. It's intended to test, measure and compare the impact strength of the specimens.
One test option
One test approach is to…
user3405291
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Water flow near dam geomechanics
I have basic Geomechanics question , one of the drawing is true and the others are wrong , which one ? , explain why the others are wrong .
First one wrong because the number of squares are not equal
Third one intersecting equal potential
Fourth…
Razi Awad
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Drained and undrained shear strength of clay correlated?
When we measure the undrained strength of clay via CPT or triaxial test for instance, is there a way to correlate this to drained strength? How? I ask because measuring drained strength takes very long time but undrained strength can be measured…
upstream
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Retaining Wall: Saturated Soil & Hydrostatic Pressure
I understand that Hydrostatic pressure and Soil pressure exist concurrently. I'm curious how these separate loads interact with each other.
Full disclaimer: I am not an engineer nor do I pretend to be one. I recognize that these are very broad &…
Cggart
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Penetration rate for miniature cone
Is there any recommended/suggested/required penetration rate for a miniature cone penetrometer? A 20mm/s is for a standard size of cone penetrometer, what about for miniature one?
shemelyn
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Civil Engineering - Detailing of free draining backfill and modelling of hydrostatic pressure in retaining walls
It is considered best practise to specify free draining backfill material (eg gravel) to be placed immediately behind a retaining wall. Supposedly, this alleviates hydrostatic pressure on the wall, allowing more economical designs to be achieved.…
thevincent0001
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When settlement criteria of a foundation is satisfied, bearing criteria is also automatically satisfied?
We design the foundations to settlement criteria than bearing correct? Because settlement criteria is stricter? I mean, can there be an example where the settlement criteria is satisfied but bearing is not? Can you think of such example? If not,…
upstream
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Effect of overburden pressure on the skin friction pile capacity
In a given soil, the lateral effect of overburden pressure is constant with depth, as in $p=qk$, where:
$p$: lateral pressure effect,
$q$: overburden pressure
$k$: soil lateral pressure coefficient.
Then, the effect of this overburden pressure on…
upstream
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Does Eurocode allow use of Robertson chart to determine soil type based on CPT results?
It seems that use of the Robertson charts (Robertson, P.K. [1990] " Soil Classification using the cone penetration test" Canadian Geotechnical Journal 27(1), 141-8) to classify soil type based on CPT results is widely accepted practice in the…
user32882
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Liquid Limit of Soil through Atterberg Tests
My lab is evaluating the liquid, plastic, and shrinkage limits of some soil samples and we are following this video provided by the Missouri University of Science and Technology. The video indicates we should conduct at least 3 tests where it takes…
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What is the physical meaning of Cumulative Passing% in Grain Size distribution?
When preforming a grain size distribution on a sample of Soil using Mechanical Sieves (e.g. Sieve #4 and sieve #10 and sieve #40) one of the necessary calculation need for drawing the particle size distribution curve is the Cumulative Passing…
user10597
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