Using modified Hiley's formula, determine the safe load that can be carried by a pile. The gross weight of the pile is $2500kg,$ weight of hammer $3500kg,$ height of fall $90cm,$ hammer efficiency $78\%,$ average penetration under the last $5$ blows is $10mm,$ coefficient of restitution is $0\mathrm{.}55$ and the factor of safety is $2\mathrm{.}5.$ assume $C=2\mathrm{.}5$ and $e=0\mathrm{.}5$