Soil-pile-structure-interaction: Experimental results and numerical simulations

The complex seismic soil-pile-structure interaction phenomenon is related to the interaction between foundation and structure under seismic and dynamic excitations. An effective way to assess such phenomenon is to analyse the response of scaled physical model in 1-g or n-g devices. In this study some results selected from a comprehensive 1-g shaking table tests are reported and discussed. The extensive experimental campaign was carried out on the 3mx3m shaking table of the Bristol Laboratory for Advanced Dynamics Engineering (BLADE) at the University of Bristol (UK), within the framework of the Seismic Engineering Research Infrastructures for European Synergies (SERIES). The physical model comprises a pile group embedded in a by-layer soil deposit with different pile configurations. This paper focuses on the pile group response generated by the presence of a cantilever system (a single-degree-of-freedom, SDOF) connected at the top of the central pile considering no connection among the other pile heads. The selected input motions consist of a set of sinedwell excitations for SDOFs with different structural masses. The experimental data are used to validate an advanced 2D difference element model using the FLAC2D code. The comparisons between the experimental and the numerical results are presented in terms of both envelope and time histories for the free-field and piles responses. The SDOF response is also assessed in terms of displacement time histories. Comparisons between the numerical and experimental test results appear satisfactory; hence numerical approach can be used for further simulations of the soil-pile-structure interaction phenomena.