Author/Authors :
Oliaei Mohammad نويسنده is Assistant Professor of Civil Engineering. , Manafi Ehsan نويسنده received his MSc degree in Geotechnical Engineering at the Department of Civil Engineering, from Tarbiat Modares University
Abstract :
The development of transportation in large cities requires the construction of
twin-tunnels or the construction of new tunnels close to the existing ones. Since both the
relative position of tunnels and the construction procedure a ect the soil movement, this
paper presents analysis of this issue with a particular interest for the optimization of both
the relative position of the twin-tunnels and the construction procedure. Since the soil is
composed of discrete particles with di erent sizes, modeling using nite element methods
based on the mechanics of a continuous medium is not completely consistent with reality
(especially, modeling of con ning e ect with depth). Therefore, in this study, discrete
element method is used to model the discontinuum nature of soils. For these concerns, using
software PFC2D based on Discrete Element Method (DEM), the static analysis of circular
twin-tunnels has been performed, and in
uence of the two factors on the soil settlement
resulting from the tunnel construction has been investigated. Analyses were conducted for
three con gurations of the twin-tunnels: aligned-horizontally, vertically, and inclined. The
results are compared with the FEM results. The comparison shows in
uence of modeling
the discontinuous nature of coarse-grain alluvial soils with respect to continuous media
modeling.
