Twist deformation of buildings from ground movements due to skewed-tunnel excavation

摘要

Substantial ground settlements from tunnel excavation near existing buildings may result inrnbuilding distortion and increase the risk of structural damage. Current studies on building-tunnel interaction arernusually limited to the plane-strain analyses that neglect the out-of-plane deformation behaviour of a structure.rnWhen tunnels are orientated (skewed) to the building, additional three-dimensional deformation such as out-ofplanernground movements and building twist may lead to further building straining. Estimation of the twist is notrnalways straightforward as the building stiffness modifies the greenfield displacements induced by tunnelling.rnIn this paper, the results of a three-dimensional numerical parametric study on the influence of existing surfacernstructure on the twist deformation are presented. The buildings are represented by elastic shell elements whererntheir in-plane geometries, stiffnesses, and rotation angles with respect to the tunnel axis are varied. The resultsrnshow that in most of the cases, presence of the building reduce the global twist deformation in comparison tornthose of greenfield condition, except in the case of low building stiffness, and when the tunnel is excavated withrnskew angle less than 30◦ relative to the existing buildings.