<p>During the construction of the Bullet Train lines in Japan, several shallow tunnels were excavated in unconsolidated ground using the New Austrian Tunnelling Method (NATM). However, ground and tunnel settlements frequently occurred due to the low stiffness ...

<p>This paper deals with a shotcrete lining with steel sets. The nonlinear analyses of a reinforced shotcrete lining are performed by using fiber beam-column element, which is a forced based element on the Euler-Bernoulli beam theory. The constitutive model ...

<p>During tunneling in loose grounds, the ground deformation caused by drillings around the tunnel, leads to land subsidence and the adjacent tunnel which would affect tunnel structure and surrounding structures. In such situations it is necessary to improve ...

Since the advent of New Austrian Tunneling Method (NATM), shotcrete as a primary means of support in tunnels has been widely applied. It’s most important features are durability, speed of application and cost effectiveness. This paper introduces some tables ...

<p>One of the main objectives of this study is to investigate the effect of different parameters on the behavior of excavated tunnel before and after lining activation. The analysis followed the same procedure which had been applied in the analysis of the ...

This communication deals with the effect of tunnel face reinforcement on the wall convergence and on the loads in the lining, studied by means of a homogenized anisotropic model for reinforced ground. While the tunneling process is generally handled in a plane ...

The convergence-confinement method (CCM) for simulating NATM tunnels using plane strain finite element method was in the paper evaluated by comparison with fully 3D simulations. Three real shallow tunnels in urban environment in different stiff clays were ...

The paper investigates these issues using 3D finite element analyses of the near-face region in tunnels excavated in elasto-plastic ground following the Mohr-Coulomb failure criterion. Parametric analyses are performed by varying the density and length of ...

<p>After a short retrospect on possible elasticity the intended purpose of stress controllers as rock support elements in shotcrete construction is described. Different types of stress controllers are briefly explained. The successful development as well as ...

The paper presents the results of 3D finite element analyses of the near-face region in unsupported tunnels excavated in elasto plastic ground following the Mohr-Coulomb failure criterion. Face extrusion and ultimate face stability are investigated in parametric ...