Effect of lateral disconnections on the seismic response of shallow foundations

The paper examines the effects of removing the lateral ground connection between embedded foundations and surrounding soil on the dynamic soil-structure interaction. The lateral disconnection produces (i) a reduction in the overall stiffness leading to a decrease in the seismic actions; (ii) a shrinkage of the interaction domain of the foundation. In order to take into account both these factors the method introduced by Wolf was used to assess the actions at the structure level; the reduction in the bearing capacity due to the disconnection was estimated by suitably employing the limit analysis; finally, both the pseudo-static and the push-over methods of analysis were adopted. The proposed procedure was applied to a one-story building and a parametric analysis was carried out varying both the dimensions of the lateral disconnection and the stiffness of the foundation soil. In order to show the effectiveness of the proposed intervention, the obtained results are presented for two selected cases.