Relationship between soil suction and angle of repose

[ausineng]

I am writing a report for my civil engineering subject. and i have few questions.

is there any relationship between angle of repose and total soil suction.
is there any relationship between angle of repose and particle size distribution.
is there any relationship between angle of repose and electrical conductivity of water.
is there any relationship between angle of repose and shear strength.

i have tried looking online, but i haven't found anything solid to include in the report.
please help.
thanks

 

[Studiot]

Welcome to Physics Forums, ausineng.

Civil Engineering is an intensely practical subject. Have you done any experiments/made any measurements to test any of these relationships?

Any civ eng course will not have left you totally adrift to answer these questions ( which are pretty fundamental) so what is your basis to proceed on?

 

[ausineng]

hello
thanks for the reply.
the tests we have done are shear test, compression test, total suction test, electrical conductivity of water, ph test of water, sieving analysis, density measurement, gravimetric water content, and angle of repose.

i actually need to know how angle of repose is related to each one of the tests.

thanks

 

[Studiot]

Presumabably you have been told the difference between granular or cohesionless soils and those with cohesion?

The angle of repose is related to the shear in the material as is is the angle of the failure plane.

If ff is a failure plane at angle $\varphi$ to the horizontal then the stresses on that plane are related as follows

$\tau$_ff = c + $\sigma$_fftan($\varphi$)

Obviously for cohesionless soils, c = 0.

Normally a tau v sigma plot is a straight(ish) line with slope given by tan($\varphi$).

This plot is called the Mohr envelope.

You will have noticed that phi is affected by void ratio.

go well

 

[DeeNos]

I can provide some insights on the relationship between soil suction and angle of repose. The angle of repose is the maximum angle at which a pile of granular material can be stable without collapsing. Soil suction, on the other hand, is the force of attraction between soil particles and water.

There is a relationship between soil suction and angle of repose, as soil suction can affect the stability and strength of soil particles. Higher soil suction can increase the internal friction between particles, making it more resistant to movement or collapse. This can result in a steeper angle of repose.

The angle of repose can also be influenced by particle size distribution. Smaller particles tend to have a lower angle of repose compared to larger particles, as they have a higher surface area and can easily slide past each other. In contrast, larger particles have a higher angle of repose due to their weight and ability to interlock with each other.

The electrical conductivity of water can also play a role in the angle of repose. Water with a higher electrical conductivity can increase soil suction, leading to a higher angle of repose. This is because the ions in the water can attract and bind to soil particles, increasing their stability.

Lastly, there is a relationship between angle of repose and shear strength. The angle of repose is a good indicator of the shear strength of soil, as it represents the maximum angle at which soil particles can resist shear stress before failure. A higher angle of repose indicates a higher shear strength of the soil.

I understand that you have had difficulties finding solid information online. I would suggest consulting with your professor or a civil engineering expert for more specific and detailed information for your report. Additionally, conducting experiments or simulations can also provide valuable data to support your findings. I hope this helps. Good luck with your report!