Numerical Study of the Seismic Response of Closed-Ended Pipe Pile in Cohesionless Soils

Closed-ended pipe piles are usually preferred over traditional piles because they are simpler and easier to handle. Also, their quality could be verified easily and at a low cost. However, the seismic response of these piles is still not clearly understood. Therefore, this paper examines the seismic performance of closed-ended pipe piles embedded in dry and saturated cohesionless soils using a validated three-dimensional finite element model. The effect of the pile material, slenderness ratio, peak ground acceleration (PGA), and soil state (i.e., dry or saturated) are considered. Four earthquake records have been used in the stress-nonlinear time history coupled analysis. It is found that the pore water pressure ratio rises as the PGA or the pile slenderness ratio increases. In addition, the lateral displacement is found to increase nonlinearly with the increase of the PGA for both dry and saturated conditions. This lateral displacement also increases as the slenderness ratio rises. A similar trend of that noticed for the lateral displacement is also noticed for the bending moment. However, the trend of the relationship between the shaft resistance and the PGA is found to depend on the soil state and soil density. Importantly, design charts have been proposed based on the results of the present study to make the results useful in the future to designers and researchers.