Two identical concrete piles having the plan dimensions $50 \: cm \times 50 \: cm$ are driven into a homogeneous sandy layers as shown in the figures. Consider the bearing capacity factor $N_q$ for $\phi = 30 ^{\circ}$ as $24$.
If $Q_{P1}$ and $Q_{P2}$ represent the ultimate point bearing resistances of the piles under dry and submerged conditions, respectively, which one of the following statements is correct?
- $Q_{P1} > Q_{P2}$ by about $100 \%$
- $Q_{P1} < Q_{P2}$ by about $100 \%$
- $Q_{P1} > Q_{P2}$ by about $5 \%$
- $Q_{P1} < Q_{P2}$ by about $5 \%$