Conventional Method to Estimate Settlement of Plate Subjected to Bi-Axial Loading – Part II

Abstract

A plate bi-axially loaded presents the general loading case of shallow foundations. Raft its columns load resultant does not lay on its center of area is one example. Isolated footing subjected to moment and vertical load eccentric or concentric is another example. Not to mention if wind or seismic effect is considered or involved. Even though, most of conventional methods were developed to predict settlement induced due to concentric loading conditions. This research presents novel simplified method for settlement prediction of rigid plate center and corners subjected to bi-axial load. The method works for rectangular plate rests on Mohr-Coulomb soil having any L/B ratio, starting from square up to strip footing. Also it suits any E_S and µ_S values. This method uses one graph that contains two curves; alternatively two empirical equations have been given. The generalization of this method is proved analytically. The used methodology and method to develop this technique was parametric study, finite element, Plaxis 3D, and first principals. Furthermore, an experimental investigation has been performed. A physical model has been manufactured and used to run series of tests. Steel rigid plates rest on dense sand and bi-axially loaded have been tested. Various lengths to breadth ratio L/B as well as several bi-axial eccentricities are examined. Moreover and above, the experimental study has been extended to cover field work. There a series of bi-axially loaded plates having different length to breadth ratios L/B were researched. The behaviour of the plate based on experimental work confirms and match the suggested conventional method behaviour. However, elimination of scale effect could be achieved by using more advanced physical models, such as wind tunnel. This is suggested as a further research work.