A comparative study on pile group and piled raft foundations (PRF) behavior under seismic loading



Study on the seismic behavior of piled rafts and pile groups while the same amount of construction material and excavation is used in their construction, are the main objective of this research. The process where the raft interaction with soil can affect the seismic response and stress distribution is also discussed in the current study. By means, ABAQUS software was applied for the finite element modeling. Firstly, for calibration and verification of the procedure of modeling with two other experimental studies, results were compared by the analysis of models under single frequency sinusoidal dynamic loads. Moreover, analyses of the same models were applied under the acceleration time history of the El-Centro earthquake. Results indicate that the participation of the raft interaction with soil under seismic loading, well improves the seismic response and behavior of a piled foundation systems i.e. internal moments and shear forces as well as deflection. Reductions of maximum acceleration response, horizontal displacement and bending moment in the piled raft system, are some important gained results by this study. In addition, the more uniform stress distribution in soil deposit and prevention of stress concentration leads to the reduction of the piled rafts settlement during earthquakes.