ABSTRACT
A refinement strategy mesh is described for an upper bound procedure using smoothed finite element method and second-order cone programming. Central to adaptive mesh refinement strategy is the plastic dissipations gap of neighbouring elements which is directly derived from the upper bound solutions. The refinement scheme is then applied to assess how seismic conditions influence the stability of circular tunnels. In simulations, soil behaviour is assumed as a cohesionless frictional Mohr-Coulomb material in conjunction with the associated flow rule. Dependency of safety factors and failure mechanisms on the magnitude of seismic acceleration is intensively examined; results confrim that inclusion of psuedo-static seismic loading in computation simulations reduces the safety factor for the wightless soil. Moreover, the current performance proves its efficiency when producing better results of the safety factor than the existing standard finite element method and is able to reveal the slip-line failure mechanism as noted by Martin (2011).
