Centrifuge model tests on liquefaction-induced settlement and pore water migration in non-homogeneous soil deposits

• Model tests were conducted to investigate the liquefaction in non-homogeneous soil deposits.
• Non-homogeneity is incorporated by including periodically distributed silt patches.
• Pore water pressure remains high for a longer period of time at discontinuous region.
• Dissipation of pore pressure through discontinuity manifests larger settlement.

This paper presents the results of dynamic centrifuge model tests conducted to investigate the liquefaction mechanism in non-homogeneous soil deposits. Four types of model tests were conducted: one model test involved a uniform soil deposit; one involved continuous layered soil deposit; and two involved discontinuous layered soil deposits. Non-homogeneity in the tests was incorporated by including periodically distributed discontinuous silty sand patches. It was found that more excess pore water pressure (EPWP) remains for a longer period of time in the discontinuous region in non-homogeneous soil deposits compared with the continuous layered and uniform soil deposits. The generation of pore water pressure ceases the supply of a new mass of water after seismic excitation; therefore the dissipation of EPWP becomes the dominant factor for settlement after seismic excitation. The rapid dissipation of EPWP through the discontinuous part in the non-homogeneous soil deposits manifests as a larger settlement in the discontinuous part, causing non-uniform settlements.