A circular pile of $600 \text{ mm}$ diameter and $6 \text{ m}$ length is embedded in a saturated clayey soil. Undrained cohesion of the soil is $80 \text{ kPa}$ . Unit weight of the soil is $19.20 ~\mathrm{kN} / \mathrm{m}^{3}$. The adhesion factor is $0.54$. If the diameter of the pile is doubled to $1200 \text{ mm}$ (keeping the length constant), the ratio of pile capacity of $1200 \text{ mm}$ diameter pile to that of $600 \text{ mm}$ diameter pile is $\_\_\_\_$ (rounded off to two decimal places).
