Question $9($Elastic Settlement: $10$ Marks$)$

Representative data of the elasticity with depth in a sand varies considerably as shown in the table

below. This variation can be attributed significant variations in the sand deposit.

It is proposed to construct a continuous footing with $\frac{L}{B}>15,$ on this soil that has a foundation depth

equal to $2\mathrm{.}2m$ and width equal to $2\mathrm{.}2m.$ Assume $=20k\frac{N}{m^3}$ and creep time of $10$ years for the

correction factor $C_2.$ Use engineering judgement and calculate the expected maximum elastic

settlement of the foundation using the given data $($Hint: you don't have to do calculations using all

the sets of data$).$ Use Schmertmann's strain influence factor method for calculations. The stress at the

level of foundation is equal to $125$kPa.

Comment on the elastic settlement value you have obtained. Does it meet the design requirements with

respect to settlement criteria? What measures you suggest to improve the sand properties if it does not

meet the requirements.