Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Clay is more porous than sand. The Permeability of sand is higher.

The reason for that is clay particles are platy and smaller in size which allows it to have more void space as a total, however, the individual spaces are smaller in size than the void spaces created by the sand particles. Other factors affecting the analysis is the tendency of clay to swell which allows it to have even higher volume than the sand. The Degree of compaction and initial void ratio and initial moisture content are other factors. In controlled testing where equal volumes of clay and sand (clay is suppressed with surcharge weights to avoid swelling), the porosity of clay would be higher than that of sand. The permeability of sand is obviously higher than clay which is not debatable.

I think Option B is the correct answer.

Aluminous cement is used for what type of chemical deposit?

As the size of the particle decreases, porosity will increases. Hence on comparing the clay and sand particle, clay is having greater porosity. Even though the porosity of clay is higher, it doesn't mean that its permeability is more than sand. Since only interconnected pores will allow the passage of fluid.

Clays: Porous but impermeable (i. E they store water but not yield them back, because of tight molecular structure) as Aquicludes.

While Sand: yield sufficiently and are highly permeable (because of large grain size) but not as porous than clay.

Guys porosity is the water bearing capacity.

Clay can hold more water than sand.

This can easily be understood by flour wheat example as after grinding of wheat it's volume increase as flour is finer its void ratio increases hence clay is porous than sand.

This answer is wrong as sands are more porous clays.

Clay is impermeable in nature.

Sand has high permeability.

Clay is more porous than sand and sand has more permeability than clay.