# Questions tagged [soil]

Questions related to the use of soils in engineering, as a material, or as object of research. Some common uses in Civil engineering are as surface for water flow, for foundations, as part of pavement structure, as seepage medium, or as origin of loads over other structures. Other uses in agronomic engineering, or biology, are as medium for storage of water, cultivation, as an erosionable agent, as a souce of receiver of contaminants.

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### Obtaining fundamental soil parameters given only soil average density, sample volume, and mass

Assume that there a soil sample has a known density $\rho$, volume V, and mass m. Given only this information, is it possible to obtain fundamental soil parameters for cohesion, internal friction ...
24 views

### Volumetric water content and EC measurement by Teros 12 sensors from Meter

We are doing Mid scale experiment in lab with soil. We are using Teros 12 sensors from Meter Group to measure the volumetric water content (VWC) and electrical conductivity (EC) of the soil. I wanted ...
68 views

### 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 ...
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### Relation of shear strength to bearing strength of soil by formula

From formulas: Shear Strength: $τ = c+ σ'\cdot sin\phi$ Bearing strength such as: $1.3 cN_c+ qN_q + 0.4B_γN_γ$ Now I know that bearing capacity decreases as the shear strength of soil decreases. ...
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1 vote
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### Effect of area spring at slab on column

Say that a simple building is supported by 4 columns , the column sitting on base slab. I assigned some sort of area spring to the base slab. When the area spring assigned is higher, this cause the ...
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268 views

### Force required to vertically pull a post out of ground with various soil types

I am trying to determine the force required to vertically lift a typical traffic sign post (round, square and/or channel) out of the ground based on typical soil types at standard installation below ...
1 vote
210 views

### PE exam: situations in which two question choices are close to my final answer: how to pick one?

Consider this question: I solve this eventual question and my answer is 7.29667: Among the question choices are 7 x 7 ft and <...
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1 vote
1k views

### 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, ...
100 views

### Hydrostatic Pressure in Soil

In a saturated soil, why is the pore water pressure equal to hydrostatic pressure? Terzaghi's principle states that the effective stress between solid particles is equal to the total stress $t$ minus ...
1k views

### Why is the wet/dry boundary of ground not dangerous for foundations?

A building, such as a house, rests on a foundation. Beneath it is natural earth. When it rains, the ground around the foundation becomes wet. But the ground underneath the foundation does not. There ...
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86 views

### Missing items in geotechnical reports [closed]

In your experience, what items that should be in geotechnical reports are sometimes missing, and what do you do in that case, can you provide example? Do we look at codes or make best guess and based ...
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1 vote
132 views

### 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 ...
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### How much does the weight of urban structures (buildings) affect the compaction (permeability, porosity, density) of alluvial sediments below a city?

Original Question was here. I live in Van, Turkey. Van City is situated on an alluvial plain beside Lake Van. General geological structure of the area can be seen on pages 43-44 in this conference ...
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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 ...
320 views

### 3 x 1 stone under footing and sump crock

I am having a house built and the builder found organic soils during the excavation. They removed the soils and then filled the cavity with 1x3 stone (see picture). This is the corner where the sump ...
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### Soil mechanics-Geotechnical engineering [closed]

Which is more economical to improve or change the soil that is used to build a structure? my answer is that it depends on each case, but I would like to get more information, or where to search about ...
1 vote
615 views

### Is it possible to calculate Young's Modulus of Clay from load-controlled tests?

I'm trying to get the compressive strength (and Young's modulus) of a clay sample. The method I found is called 'Unconfined Compressive Strength of Cohesive Soil'. According to ASTM D2166M, I have ...
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### What diameter of particles will result in a blocked borehole?

My mine is looking to install a 600 mm open borehole to drop particles up to 150 mm through. It's a 320m shaft to drop ballast down to save time compared to using the drift. When it gets blocked ...
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1 vote
153 views

### How would you calculate the force needed to rotate along the x axis vertical earth anchor in dirt?

I'm a high school student who hasn't had the pleasure of taking physics yet, so forgive me if the answer is obvious. The problem I have involves an earth anchor drilled vertically into the earth. I ...
1 vote
474 views

### 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 ...
1 vote
39 views

### Is it possible to reuse or the oil recovered from a spill?

I don´t know if this is the rifght place to ask this question, but I would like to know if after the remediation of a soil contaminated with hydrocarbon you can reuse or even sell the oil recovered. ...
836 views

### Why is this construction site pouring gravel over a wire mesh, and then covering it with dirt?

My office is afforded a prime view of a construction project where the workers are currently covering the leveled ground in a wire mesh, raking gravel across the entire mesh, and then covering that ...
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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 ...
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### What is a safe soil load to avoid settlement?

For residential design, looking at IBC 2012 Table 1806.2 it seems a safe soil load to design for is 1500 psf if you want to save time and cost isn't yet an issue. (assuming you're not building on a ...
1 vote
12k views

### 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 ...
2k views

### Total lateral pressure from clay soil when hydrostatic pressure is also present

I'm stuck with how to work out the total pressure and centre of pressure in this example. At an outdoor boundary between two properties there is a stepped change in ground level of the clay soil. The ...
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1 vote
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### How to derive Darcy's law only in the case of saturated soil without derived all cases?

How to derive Darcy's law only in the case of saturated soil in mathematical/theoretical way without having to derive all the cases? I can only find the generalized theoretical proof for all cased ...
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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?
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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 ...
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### What paint/spray on material should I use to insulate a metal pole?

I am not entirely sure if this is the correct forum to ask this question so please refer me on if there is a better arena. I am creating a small weather station and I wish to measure soil ...
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### How to determine the lateral earth pressure in a double-walled cofferdam?

The design of a retaining wall commonly involves determining the lateral earth pressure using either Rankine theory or Coulomb theory. Both theories involve mobilising the shear resistance of a ...
180 views

### How are the structural properties of intentionally frozen soil determined?

Soil freezes naturally all of the time. It is at this point that dirt work usually stops. Occasionally soil is intentionally frozen to improve its structural properties. This process has been used ...
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### What is the unbraced length of a pile in soil?

When analyzing a pile or drilled shaft as a beam-column, how do you determine the unbraced length of the portion that is in the ground? Typically, the braced points on a beam or column are well ...
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### Soil swelling and mass/volume relationships

Given moisture content, Specific gravity of solids, initial volume, and weight. I'm asked to compute the moist unit weight, dry unit weight, and degree of saturation of this compacted soil. This is ...
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