Accurate simulation of Pile-Tunnel interaction is crucial for the prediction of tunneling induced forces on nearby
piled foundation and pile loading induced loads on existing tunnel lining. Number of studies in the literature
investigated tunneling effect on piles numerically, by centrifuge modeling or by field monitoring. However, the
effect of piles on tunnels, especially laterally loaded ones, is not well understood. This paper describes the
application of 3D finite element model (FEM) to predict pile loading, vertically and laterally, effect on a nearby
existing tunnel. Back analysis of a case history of greenfield tunneling and building response using 3D FEM show
good agreement between predicted and observed displacements. The FEM applicability to simulate Pile-Tunnel
interaction problem is proved by back analysis of field case study. The results of parametric studies show that pile
loading increase bending moment, axial compression force and induce new tension force on tunnel lining with
different percentage depending on Pile-Tunnel configuration. An influence zone of Loaded pile effect on existing
tunnel is identified by clearance of 2DT and HT/LP ratio of 1.25. However, lateral load effect is more significant
through a clearance of DT and HT/LP ratio of 0.5. Lateral load on pile contributes by 50% of induced B.M, 17%
of induced compression axial force, 2% of induced tension axial force on tunnel lining and 100% of lateral
deformation. On the other hand, pile axial load causes about 95% of induced vertical deformation of tunnel lining. |
