ABSTRACT
A. Garduno & J. Resendiz Comision Federal de Electricidad, Mexico, D.F., Mexico
ABSTRACT: The Hydroelectric System located 60 km southwest from Toluca City, combines 6 hydropower plants, with regulator dams, tunnels and channels. The construction of the system started in 1938 and was finished in 1965. The intention is that all the structures work in optimum conditions, regardless their age. In 2007, during the inspection of a 2200 m concrete conduction tunnel a great amount of water coming through a lot of transversal and longitudinal construction joints was found. It was needed to seal them and reduce the loss of water during the operation of the tunnel, as well as to reduce the risk of geotechnical problems. This paper describes the materials (expanding polyurethane grout), equipment (and its specific adaptations) and procedures used for such works, including planning aspects and safety issues for the works. The tunnel was successfully sealed and it is now working.
