Influence of shallow footings on the dynamic response of saturated sand with low confining pressure

Abstract This research addresses the dynamic response of closely adjacent shallow footings on saturated sand with low confining pressure. This was achieved by performing physical experiments. A large laminar box, filled with sand, on a shake table, was used to simulate the soil-foundation interaction. The subsurface acceleration and the excess pore-pressure were measured along with the acceleration of the footings. A stand-alone footing, three adjacent footings aligned with the axis of shaking and a cluster of six footings (two rows of three footings) were studied. Harmonic waves and seismic ground motions were used. Results show a modification of the response of the footings and sand dependent on the number and location of footings. Variation in excess pore-pressure was observed partly dependent on the length of the drainage path. For the stand-alone condition, the footing acceleration was larger than that of the shake table. However, in the case of these experiments, the acceleration of the footings reduced with an increasing number of footings.