Silo Wall Pressure & Discharge Overpressure Calculator
Compute Janssen vertical and horizontal wall pressures ($p_v$, $p_h$), Walker hopper transition stress, and Eurocode 1 (EN 1991-4) discharge overpressures.
Silo Geometry & Stored Bulk Material
Wall Pressures & Cylinder Hoop Tension
Recommended Tools & Equipment
Tested hardware and components for high reliability
Janssen Bulk Solids Mechanics & Silo Failure
Unlike liquids which exert purely hydrostatic pressure ($p = \rho g z$) that increases without bound with depth, bulk granular solids transfer vertical weight directly into the silo cylinder walls via wall friction shear. In 1895, H.A. Janssen derived the fundamental exponential pressure relationship: $$p_v(z) = \frac{\gamma R_{hyd}}{k \mu} \left(1 - e^{-z / z_0}\right)$$
Discharge Overpressure & Silo Collapse
When an outlet gate opens and granular material transitions from static state to mass flow, internal stress fields switch from active state to passive state. A dynamic stress peak travels upward, multiplying lateral wall pressures by $1.3\times$ to $2.0\times$ ($C_{op}$ per Eurocode 1 EN 1991-4). Failure to reinforce for this flow overpressure is the leading cause of catastrophic corrugated steel silo ruptures.