Construction of pressure pipes for hydropower plants can be restricted by local topography. In these circumstances the pipes are replaced by pressure tunnels. Because of mining related, hydraulic and static aspects the tunnels usually have circular cross-section. The performance of unlined systems is highly dependent on the water velocity, the mechanical characteristics of the bedrock and the wall's roughness. With the roughness closely related to the plant's efficiency, unlined systems are only suitable for special cases. An alternative system, with a multilayer lining of concrete and/or armour plating, substantially reduces the hydraulic losses and also guarantees the structural stability of the tunnels. An overview of the semi-analytical structural analysis of such multilayer lined structures is subsequently described.