Computational methods

The aim of any computational analysis involving geotechnical problems consists in describing and simulating the hydro-thermo-chemo-mechanical (HTCM) processes occurring in a determined volume in an assigned period of time. This requires the solution of a system of partial derivative differential equations. To this aim, the analyst has to consider the response of the previously defined limited spatial domain over the specified time period, typically starting before the construction of the tunnel and ending many years later. Each numerical analysis simulates only a specific HTCM process. This allows us to reduce abruptly the number of unknowns, the time period and, therefore, the associated computational costs. All the simplifications deriving from this choice have to be justified by the analyst. Analogously, the system evolution preceding the considered time period has to be summarized by imposing appropriate initial conditions. Very often, thermo- and chemo-mechanical couplings are not accounted for, if not in some special cases, as for instance in energy and nuclear waste storing tunnels.