STRESS ON SOILS

Increase in Stress on Soils with Depth - Approximate (2:1) Method

The increase in stress with depth in a soil mass caused by the construction of a foundation can be calculated using an approximate method, often referred to as the 2:1 method. According to this method, the increase in stress at depth z is given by the following equation;

$△ σ = q 0 × B × L ( B + z ) ( L + z )$ where;
Δσ=vertical stress increase, kN/m2,
z= depth below footing, m.
FIGURE
Fig: Increase in Stress caused by the construction of a foundation - Approximate (2:1 Method)

Vertical Stress Increase - Approximate (2:1) Method

Vertical Stress Increase - Approximate (2:1) Method

q0 :

L :

B :

z :

Total Increased Vertical Stress, Δσz :