Bearing capacity of free-rotating and restrained footings near slopes

Loading tests on model horizontal grounds and slopes are performed using a 100-mm-wide strip footing with restrained and free-rotation conditions. Test results reveal that complete restraint against rotations on the footing generates larger values of ultimate bearing capacity and deeper failure surfaces than those for footings with a free-rotation condition. This is true for horizontal and slanted grounds with various slope angles. Test results also reveal that for a vertically loaded footing, a major factor that influences the ultimate bearing capacity of the footing (q u ) is the load eccentricity (e c ) at the footing base. The influence of load inclination on the values of q u for free-rotating and fixed footings is minor because the load inclination angles measured during the loading tests were negligibly small. In the case of a footing placed on a slanted ground, a load eccentric toward the heel of the footing is associated with a larger value of q u than that for a load eccentric toward the toe of the footing when subjected to similar extents of load eccentricity. This observation suggests that the currently used formula for correcting load eccentricity (e c ) has to be updated in order to address the issue of increased q u induced by a load eccentricity toward the heel of the footing. © 2019 Taiwan Geotechnical Society.