A numerical simulation study on ground displacement field of thaw-settlement in artificial freezing soil

To reveal the ground settlement regularities of thawing of artificial freezing soil, based on a horizontal freezing engineering project of shield tunneling for construction of a subway, the ground displacement induced by thaw-settlement in artificial freezing soil was studied with 3D numerical simulation analysis.The results showed that settlement of ground surface can be divided into 4 stages: slow settlement, rapid subsidence, stationary settlement and consolidation settlement.Above the tunnel axis, with the increase of distance from the sealed door, ground surface settlement was increased first and then decreased.Land subsidence in the cross section was similar to normal distribution curve.With the increase of horizontal distance from the axis, land subsidence was decreased and there is an obvious inflection point of the curve.With the increase of distance from the tunnel axis, the horizontal distance of land increased first and then decreased.The maximum horizontal displacement corresponds to the position of inflection point.The ground settlement above the tunnel caused by the thaw-settlement increased with the increase of depth.The ground settlement was smaller when the distance was farther away from the freezing zone.