Numerical and experimental investigation into dynamic responses of permeable pipe piles in liquefiable sands

Liquefaction of saturated sands is a leading cause of damage to roads and bridge foundations during earthquakes. To mitigate such issues, permeable pipe piles, featuring drainage holes on their shaft, have emerged as an innovative anti-liquefaction measure. However, their seismic performance in liquefiable sites has not been well understood. This study conducted both numerical and experimental tests on the dynamic response of permeable pipe piles in liquefiable sands. Before establishing the numerical model for piles, the advanced constitutive model-i.e., SANISAND adopted to the cyclic behavior of liquefiable sand was calibrated with a series of monotonic and cyclic laboratory tests. After the calibration, the numerical simulations were performed to simulate a group of shaking table tests on both traditional and permeable pipe piles in liquefiable sands. The results show that, compared with traditional pipe piles, permeable pipe piles significantly reduced liquefaction potential by dissipating excess pore water through the drainage holes, resulting in a marked decrease in pile displacement. These findings demonstrate the effectiveness of permeable pipe piles in enhancing seismic performance and provide valuable insights for their practical implementation in engineering applications.