ABSTRACT
This paper describes the structures of the repowering of the Miranda hydroelectric project in Portugal. The power increase structures consisted in construction of a new hydraulic circuit and a semi-buried powerhouse. Geomechanical tests carried out for mechanical, hydromechanical and in situ state of stress characterisation are described. Monitoring plans were established for controlling the safety of the structures during construction and first use stages. For the interpretation of the observation behaviour of the new underground structures 2-D and 3-D numerical analyses were performed considering ordinary analyses of the structural system. The numerical results obtained were compared with observed displacements.
