The correct answer is: Compressibility and permeability increase and dry strength decreases.
The liquid limit is the water content at which a soil will flow under a small applied stress. The plasticity index is a measure of the range of water contents over which a soil will behave as a plastic material. Soils with a high plasticity index are more likely to be expansive, meaning that they will swell when they come into contact with water.
When the liquid limit of a soil is increased, the soil becomes more plastic and more likely to swell. This increase in plasticity and swelling potential will lead to an increase in compressibility and permeability. The dry strength of a soil is the strength of the soil when it is dry. When the liquid limit of a soil is increased, the dry strength of the soil will decrease.
Here is a more detailed explanation of each option:
- Option A: Compressibility and permeability decrease and dry strength increases. This is not the correct answer because, as explained above, an increase in liquid limit will lead to an increase in compressibility and permeability.
- Option B: Compressibility, permeability and dry strength decrease. This is not the correct answer because, as explained above, an increase in liquid limit will lead to an increase in compressibility and permeability.
- Option C: Compressibility, permeability and dry strength increase. This is not the correct answer because, as explained above, an increase in liquid limit will lead to an increase in compressibility and permeability, but a decrease in dry strength.
- Option D: Compressibility and permeability increase and dry strength decreases. This is the correct answer because, as explained above, an increase in liquid limit will lead to an increase in compressibility and permeability, but a decrease in dry strength.