Thickness calculation for bottom plate of a Rectangular Tank subjected to hydrofill pressure

Core Engineering Principle: Rectangular Plate Analysis

This calculation follows the principle that when a rectangular plate is subjected to uniform pressure (in this case from liquid weight), it will bend and develop internal stresses. The key engineering concepts being applied are:

1. Hydrostatic Pressure Distribution

• Liquid creates pressure that increases linearly with depth
• At the bottom of the tank, the pressure reaches its maximum value
• This pressure acts uniformly across the entire bottom plate area

2. Plate Bending Theory

• The bottom plate acts as a rectangular plate supported along its edges
• Under uniform loading, the plate will deflect (bend downward)
• This bending creates internal stresses within the plate material

3. Structural Support Strategy

• The calculation considers adding stiffener beams to divide the large plate into smaller, more manageable sections
• Smaller plate sections can handle the same load with thinner material
• This is more economical than using very thick plates

4. Design Verification Process The calculation checks three critical failure modes:

• Thickness adequacy: Ensuring the plate is thick enough to resist bending without exceeding allowable stress
• Deflection control: Limiting how much the plate bends to prevent operational issues
• Stress analysis: Confirming internal stresses stay within safe material limits

This is essentially the same principle used in designing building floors, bridge decks, or any flat structural element that must support distributed loads - the engineer must ensure the plate is adequately supported and sized to handle bending forces without failure.