Question

Give the practical importance in the Building construction site for the co-efficient of volume

compressibility and coefficient of compressibility in terms of strain in the soil.

Answer 1

*Compression of the soil occurs by decrease in volume of soil which is due to decrease in void ratio or void spaces in the soil. As we all know soil fails by shear or settlement. Settlement is decrease in volume of the soil and in soil some cases this goes beyond permissible limits and even more than one meter of settlement.

Coefficient of volume compressibility and coefficient of compressibility both these values are measured based on the consolidation results of the soil.

*COFFICIENT OF COMPRESSIBILITY- it is the ratio of change in void ration to the change in effective stress values of the soil.

COEFFICIENT OF VOLUME COMPRESSIBILITY- IT IS THE RATIO OF CHANGE IN VOLUME TO THE CHANGE IN EFFCTIVE STRESS OF THE SOIL PER UNIT VOLUME OF THE SOIL.

Consolidation is applicable in saturated soils.When the saturated soils layers are under increase in stress, due to the presence of water the pore water pressure increases, the development of pore water pressure results in decrease in volume of the soil and that is due to settlement. As the consolidation process is time dependent, for sandy soil there will immideate settlement and for clay it might take years to consolidate. So certain factors like coefficient of compressibility and coefficient of volume compressibility are need to be assessed.