

Tunneling in cohesionless soil leads to ground movement. In urban environment, the ground movement may adversely affect surface or subsurface constructions. In the present study, the ground movement under the impact of tunnel construction is studied using a 3-D finite element analysis (FEA). The analysis utilizes an elasto-plastic stress-strain relationship, a yielding function of the Mohr-Coulomb type and a plastic potential function of the Drucker-Prager type. The ground movement due to tunneling is also calculated using the surface displacement equation (SDE) proposed by Peck and Schmidt (1969). For assessing the reliability of the FEA and the SDE, a case history along the Greater Cairo Metro tunnel Line 2 has been considered. A comparison between the field measurements and those obtained by the FEA and the SDE is made. The FEA has been found to give better estimate of the actual surface settlements than the SDE. Both methods of analysis have been extended to other sandy soils. The results show that the surface settlement profiles using the SDE agree reasonably well with those obtained with the FEA for loose to medium sandy soils. However, for dense to very dense sand soils, the results from the SDE do not agree well with those of the FEA. This is due to the SDE does not take into account the difference in soil denseness.