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This research aims to develop an advanced monitoring technique for assessing the stability of tunnels, which may substitute or supplement the conventionally manual procedures. In this paper, ‘laser scanning technique’ is primarily studied to determine the utilisation of laser scanners for condition monitoring of lined tunnels. A series of model tests have been carried out byusing laser scanning technology, in which models were set up simulating tunnel conditions. After scanning and processing in thecorresponding software, 3D coordinates of the models were obtained as well as 3D ‘point clouds’ models. Thus various defect targets like cracks and deformation on the tunnel wall could be identified and measured efficiently in these digital models. Precision and limitations relatedto laserscanning were also highlighted. In addition, numerical simulation would also be conducted using FLAC2D and FLAC3D software to link the simulatedtunnelbehaviourstooverallstructuralstability. This study indicates that laser scanning technique has potential for executing condition monitoring, such as depth and width of cracks, deformation of tunnels, with high accuracy in a static mode of scanning. By these observed information combined with numerical analysis, the stability of the tunnels couldbeassessedforsafety.

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. In order to study the mechanical behaviour of the masonry in brick-lined tunnels, this paper reports a series of small scale physical tunnel model tests to represent the true behaviour of a real tunnel under extreme loading. Advanced monitoring techniques of laser scanning and photogrammetry are used to record tunnel deformation and lining defects. This investigation shows how these techniques may substitute or supplement the conventional monitoring procedures. Moreover, numerical analyses based on continuum and discontinuum approaches are carried out. The numerical results are compared with physical model tests to assess the overall stability of these tunnels. Predictions using numerical models under various conditions have also been carried out to show the mechanical behaviour of masonry tunnel and to quantify the influence of the boundary and loading conditions.

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.

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.

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.

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.

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.