Abstract: As an efficient, cost effective and excellent corrosion retardation method for the installation of utility and equipment channels during the shielded tunnel excavation and, the embedded channels in the castinplace concrete shielded tunnel excavation for the urban transit system have received wide applications. Compared with the conventional utility channel installation method, the efficiency of the embedded channels has demonstrated its advantage. The corrosion performance of the imbedded structures was laboratory tested and the corrosion prevention methods for the embedded channels applied in transit tunnel projects in China have been reviewed. The cost for embedded channel with different widths are compared with the conventional anchoring method. The results indicate that, the embedment of utility and equipment channel on the forms of the castinplace concrete has a better performance than the other methods. The theoretical service life of the embedded channels could be 100 years. However, the current corrosion prevention methods applied in the existing projects will usually result in a less than 100year of service life. Due to its higher service life, the cost of the embedded channel is higher than the chemically anchored channels. However, considering the maintenance cost, the cost effectiveness of the embedded channels can still be justified.

Key words: Shield Segments, Embedded Channel, Installation Methods, Corrosion Prevention, Cost Benefits