Tintin Construction is building a $30-$level tower and is planned to have a raft foundation that is $30$ m by $30$ m$.$ The tower will be founded

$12$ m below ground surface. The soil conditions below the raft consist of $60$ m of saturated, very dense

glacial sands and gravels with SPT values greater than $50.$ The groundwater level is $5$ m below the ground surface. For the head engineer calculate and provide the subgrade modulus for use in the design of the raft. Does the subgrade modulus vary across the raft? If so$,$ plot the variation of the

subgrade modulus across the raft.