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Ch. Hellmich, F.-J Ulm, H.A. Mang:
"Multisurface Chemoplasticity II: Numerical Studies on NATM-Tunneling";
Journal of Engineering Mechanics (ASCE), 125 (1999), 6; 702 - 713.

The paper deals with the application of the multisurface chemoplastic model for shotcrete, described in a companion paper, to isothermal 2D structural analyses of tunnels driven according to the principles of the New Austrian Tunnelling Method (NATM) in drained, overconsolidated, creep-active soil. The latter is modeled by means of a viscoplastic material The influence of each ingredient of the chemplastic model on the structural behavior of the tunnel is studied. In this manner, the question is answered under which circumstances the full chemoplastic model is advisable for the description of the structural behavior of the tunnel and where more simple models are sufficient. Moreover, the nature of the soil-shotcrete interaction problem govering the NATM is elucidated by means of a dimensionless parameter, which is derived directly from the constitutive evolution equations for both soil and shotcrete.

Keywords: shotcrete, viscoplasticity, chemoplasticity, soil-shotcrete interaction, New Austrian Tunnelling Method, load-carrying behavior of tunnel, soft soil

http://dx.doi.org/10.1061/(ASCE)0733-9399(1999)125:6(702)