this paper presents the results of engineering geological studies of rock blocks along a road tunnel in nw iran. the tunnel is to cross the western alborz mountain range through 530 m in length with 11.2 m span and 8 m height. eocene tuffs and andesites crop out in whole of the tunnel route. numerical analyses are done using, a 3d stability analysis and visualization program, called unwedge tha...

This paper presents the results of engineering geological studies of rock blocks along a road tunnel in NW Iran. The tunnel is to cross the Western Alborz Mountain Range through 530 m in length with 11.2 m span and 8 m height. Eocene tuffs and andesites crop out in whole of the tunnel route. Numerical analyses are done using, a 3D stability analysis and visualization program, called Unwedge tha...

At present tunnels tend to be analyzed on the basis of 2D finite element computations , because 3D analyses are considered to be extremely time consuming. As a result, 3D analyses are presently the domain of researchers. Consulting engineers will only perform 3DFEM analyses when facing complex geometries, e.g. tunnel joints or connections to underground stations, but not for straight-ahead tunn...

The design of underground spaces is mainly carried out using empirical, analytical, and numerical methods. The convergence confinement method (CCM) is an analytical technique that is widely utilized in analyzing the stability of underground spaces. However, the main challenge in the stability analysis is the selection of an accurate constitutive model for rock mass, and particularly, its post-f...

This paper focuses on the face stability analysis of Double-O-Tube shield tunnel. This kind of analysis is significant to ensure the safety of workers and reduce the influence on the surrounding environment. The key point of the stability analysis is to determine the supporting pressure applied to the face by the shield. A collapse failure will occur when the supporting pressure is not sufficie...

A new risk analysis system for estimating the risk factors in tunneling is suggested in consideration of the complex effect in tunnel construction. It is verified that various risk factors can be expressed by stability and environment index using numerical and statistical analysis. Stability index includes the factors of safety of ground condition, the amount of ground settlement, condition of ...

the rock masses in a construction site of underground cavern are generally not continuous, due to the presence of discontinuities, such as bedding, joints, faults, and fractures. the performance of an underground cavern is principally ruled by the mechanical behaviors of the discontinuities in the vicinity of the cavern. during underground excavation, many surrounding rock failures have close r...

Purpose. This work aims to study the tunnel face stability (Algiers subway Tunnel) and evaluate common numerical procedures that are used for analyzing stability. Two-dimensional (2D) three-dimensional (3D) Finite Element (FE) modeling using PLAXIS programs. Methodology. Tunneling is executed by NATM method; two types of calculations used. The first one done reducing applied pressure until coll...