Bearing capacity of eccentrically loaded rectangular foundation on sand

Purkayastha and Char (1977) conducted a theoretical analysis for the bearing capacity of eccentrically loaded shallow strip foundation supported by sand and proposed a relationship for a reduction factor (Rk). The reduction factor is the ratio of the bearing capacity with eccentric loading to that with centric loading at the same embedment ratio (Df/B). The reduction factor was a function of Df/B and e/B (e = load eccentricity). It was not a function of the soil friction angle. The present study extends the concept of reduction factor to shallow rectangular foundations. To achieve that, a number of laboratory model tests on rectangular shallow foundations were conducted. The width-to-length ratio of the foundation was varied as 1.0, 0.5, 0.333, and zero, and the embedment ratio was varied as 0, 0.5, and 1.0. The load eccentricity ratios (e/B) were 0, 0.05, 0.1, and 0.15. Based on the laboratory test results, an empirical reduction factor (Rk) has been developed which is a function of e/B and B/L