Diameter of bolts

Try ko lang sir.
 

The total hydrostatic force is acting upward:
$F = \gamma V = 9810 \left[ \dfrac{\pi}{4}(0.4^2)(0.8) - \dfrac{1}{2} \cdot \dfrac{4}{3}\pi (0.2^3) \right]$

$F = 821.84 \text{ N}$
 

Tensile force carried by each bolt
$T = \frac{1}{4}F = 205.46 \text{ N}$
 

Diameter of bolt based on axial stress
$\sigma = \dfrac{T}{A}$

$1 = \dfrac{205.46}{\frac{1}{4}\pi d^2}$

$d = 16.17 \text{ mm}$
 

Not sure kung tama pagka analyze ko at hindi ko pa naisip paano kukunin ang due sa shear. Naghahanap kasi ako ng thickness the bolt-head or thickness ng nuts. Ang naisip ko lang kasi na shear ay yung shear failure sa thread or shear failure ng head. I can't imagine pa how to solve with shear na parallel sa area ng bolt ang force.
 

Parang nakita ko na 'to na problem sa file ko long ago, triny ko pagkalkal pero di ko nahanap, hehehe.