Kinematic Internal Forces of Free-Head Single Piles Subjected to Seismic Loading: Shaking Table Testing and Numerical Simulation

Abstract

Soil and pile interaction could significantly contribute to the response of the system and should be considered in the design prospect. To address some of the uncertainties, a series of 1 g shaking table tests followed by numerical simulations were conducted to address the seismic response of free-head single piles embedded in dry sand subjected to seismic waves of which horizontal acceleration and bending moments are the prime indexes. Subsequently, the validated numerical model was employed to perform parametric studies, focusing on normalized induced kinematic forces based on the soil profile type. The numerical results showed that not only does the soil profile type considerably affect the amplitudes of the maximum normalized seismic forces but also the distributions of these response parameters are highly dependent on soil type. The results also demonstrated that neglecting slippage and/or separation along the soil–pile interface leads to underestimation of the maximum normalized kinematic bending moment and shear force by up to 17.5% and 70%, respectively. Soil type also affects the induced forces by about 60% indicating that the design consequence of which could be dire. Therefore, it is concluded that the effects of slippage and/or separation can be considerable and hence, should be taken into consideration to prevent probable damages in seismic areas.