NUMERICAL SIMULATIONS OF STAGED TUNNEL CONSTRUCTION FOR IDENTIFYING CRITICAL PHASES IN DESIGN

The powerful capacity of numerical methods of structural analysis allows the possibility of simulating the different phases of advance in geotechnical works, being able to identify critical situations at the design stage. This is particularly valid for tunnelling where many ground failures can be theoretically predicted before starting the process of construction, sometimes involving more dangerous conditions than the final situation. It is suggested, by means of field examples, that tunnel designers should use staged construction modelling by finite element methods, in order to avoid those risks, especially for tunnels opened in soils and weak rocks