If undrained cohesion is 45 kN/m$^{2}$ and the pile spacing is 1 m centre to centre. What is the capacity of group? Take factor of safety of 2 and adhesion factor as 0.7.

Given Data: $$ \begin{array}{l} D=0.3 \mathrm{~m} \\ L=9 \mathrm{~m} \\ C_{U}=45 \mathrm{kN} / \mathrm{m}^{2} \\ \text { FOS }=2 \\ \alpha=0.7 \end{array} $$

• Case I: Considering as individual pile, we get,

$$ Q_{u}=Q_{PU}+Q_{f} $$ $$ \begin{array}{l} Q_{U}=Q_{P U}+Q_{f} \\ Q_{U}=C_{U} N_{C} A_{b}+alpha*C_{U}A_{S} \\ Q_{U}=\left(45 \times 9 \times \frac{\pi}{4} \times …