Improvement of Bearing Capacity of Footings Using Reinforced Granular Trench

Recent evidence suggests that the stability performance of footings can be greatly enhanced using a granular trench. Therefore, this paper sets out to study the bearing capacity of strip footing on a two-layered soil system that is composed of overlying granular fill above the undrained clay with an inclusion of a granular trench. The study also considers reinforced as well as unreinforced conditions at the interface of a two-layered soil system. An efficiency factor (ξ) of bearing capacity is defined by the ratio of the improved bearing capacity (pum) of strip footing in a two-layered soil system to the bearing capacity of strip footing over the original clay soil (pu). Numerical formulations are implemented by employing lower bound finite element limit analysis to study the bearing capacity of strip footing using LINPROG in MATLAB. The numerical models are validated with available results in the literature. Several parametric studies were performed for various settings, such as with or without granular trench and/or reinforced granular fill. The produced charts should, therefore, be of use to practitioners.