Shallow Footing Response on Sands Using a Direct Method Based on Cone Penetration Tests

Full-scale load tests on 31 large footings situated on 13 different quartz-silica sand sites are used to develop a direct means for evaluating the vertical load-displacement and capacity response using tip resistances (qc) from cone penetration tests (CPT). Only large size foundations with footing widths 0.5 m ≤ B ≤ 6 m were considered in order to avert difficulties found in scaling of small model test results. As no clear peak was observed, a reference "capacity" criterion is taken as the load corresponding to the s/B = 10% criterion, where s = footing displacement. It is found that the applied footing stress (q) vs. displacement (s/B) curves for all cases are unified when the foundation stress is normalized by the cone tip resistance.