Analytical model for bearing capacity of two closely spaced foundations

In this study, a new analysis has been developed to determine the bearing capacity of soil under interference of two asymmetric strip foundations conditions. The limit equilibrium method is used considering the soil failure theory under a rough based strip foundation. Three equations are developed to determine the values of the efficiency factors resulting from the effect of interference of foundations for the surcharge, cohesion, and weight. The effect of variable factors on the equations, which represent the angle of friction, the distance between the foundations and the width of the foundations has been studied, and the results have shown that when the interference occurs between the foundations, the soil bearing capacity increases with the increase in the angle of friction and decrease the distance between the foundations, while the change in the width of the foundations has just an effect on interference factor related to the soil weight, ζ_γ. Comparing the results of the present mathematical model with the results of available theoretical analyses and previous experimental studies shows acceptable and reliable agreement.