Assessment of the bearing capacity of foundations on rock masses subjected to seismic and seepage loads

Abstract

It is usual to adopt the seismic force acting as an additional body force, employing the pseudo-static hypothesis, when considering earthquakes in the estimation of the bearing capacity of foundations. A similar approach in seepage studies can be applied for the pore pressure’s consideration as an external force. In the present study, the bearing capacity of shallow foundations on rock masses considering the presence of the pseudo-static load was developed by applying an analytical solution for the Modified Hoek and Brown failure criterion. Calculations were performed adopting various inclinations of the load and the slope on the edge of the foundation, as well as different values of the vertical and horizontal components of the pseudo-static load. The results are presented in the form of charts to allow an affordable and immediate practical application for footing problems in the event of seismic loads or seepages. Finally, and to validate the analytical solution presented, a numerical study was developed applying the finite difference method to estimate the bearing capacity of a shallow foundation on a rock mass considering the presence of an additional horizontal force that could be caused by an earthquake or a seepage.