Physical model tests and numerical simulation for assessing the stability of tunnels

Nowadays, numerical modelling is increasingly used to assess the stability of tunnels and underground caverns. However, an analysis of the mechanical behaviour of existing brick-lined tunnels remains challenging due to the complex material components. One promising approach is to carry out a series of small-scale physical tunnel model tests representing the true behaviour of a prototype under extreme loading in order to validate and develop the corresponding numerical models. A physical model test is advisable before any field study, which might be dangerous and costly. During the tests, advanced monitoring techniques such as the laser scanning and photogrammetry would be used to register tunnel deformation and lining defects. This investigation will show how these may substitute or supplement the conventional manual procedures. Simultaneously, numerical models will be developed, primarily using FLAC and UDEC software, to simulate the physical models after comparing their results. In this way, numerical simulations of physical models would be achieved and verified. These numerical models could then be applied to the field study in the future research, enabling accurate prediction of the actual mechanical behaviour of a masonry tunnel, in combination with advanced monitoring techniques.