Seasonal Frost Impact on Liquefaction-Induced Lateral Spreading

Liquefaction-induced lateral spreading can cause significant deformations and damage in structures, such as bridges, highways, and pipelines, including the broad cold regions. This paper assesses how a seasonally occurring ground crust would affect liquefaction-induced lateral spreading. One-dimensional, plane-strain analyses with shear beam boundary conditions were performed with OpenSeesPL, using the soil profile at the Slana River site and a pressure-dependent multiple yield surface constitutive model for liquefaction simulation. Four cases, including the base case (no seasonal frost) and cases with seasonal frost of 0.3, 1, or 2 m thick, were considered. The East–West motion recorded at Pump station #10 of the Trans-Alaska Pipeline System during the 2002 Denali earthquake was used as the base input. The results, including the time histories of acceleration, excess pore water pressure ratio, shear strain, and ground lateral spreading for selected depths, are presented. The results show that seasonal frost has a minor impact on the lateral spread displacement induced by liquefaction for the study site with a silty gravelly fill of relatively low permeability. Moreover, a parametric study was carried out to analyze the impact of the permeability of the fill on the triggering of liquefaction and ground surface lateral displacement. The medium sand layer almost entirely liquefies when the permeability of the fill is equal to or less than 10⁻⁵ m/s, resulting in larger lateral spreading displacements.