Deformations of the shallow tunnels in flysch rock mass.

Two tunnels, up to 55 m below the surface, have been excavated inside the slope of a river valley during reservoir construction in the Carpathian Mountains in southern Poland. They were constructed through strong and hard sandstone beds interbedded with weak and soft clay shales and intersected by two systems of joints. Systematic measurements of roof settlements, convergence and surface settlement were collected during tunnelling and used as the basis for modelling deformation processes and the relationships between tunnel roof and ground surface settlements.
Two tunnels, up to 55 m below the surface, have been excavated inside the slope of a river valley during reservoir construction in the Carpathian Mountains in southern Poland. They were constructed through strong and hard sandstone beds interbedded with weak and soft clay shales and intersected by two systems of joints. Systematic measurements of roof settlements, convergence and surface settlement were collected during tunnelling and used as the basis for modelling deformation processes and the relationships between tunnel roof and ground surface settlements.