ABSTRACT
In this paper, we address the problem of tunnel face stability in multiple types of ground with a holistic view taking into account a number of the most influencing parameters. We incorporate a recently modified objective systems approach to this topic and a Face Vulnerability Index (FVI) is presented for the first time to assess the stability conditions of tunnels in subsoil. A comprehensive worldwide database of mechanized tunneling case histories is established for this purpose, and the interactions among the parameters are objectively coded by using a soft computing method’s capabilities. The results –the FVI predictions- are compared with a number of well-known analytical methods and the actual applied face-support pressures. A good agreement between predictions and measurements has been found that proves the field applicability of the new index to a great extent, which has led to the suggestion of design graphs for future applications.
