TUNNELLING THROUGH HONG KONG MARINE DEPOSITS.

This paper discusses the nature of Hong Kong's marine deposits, the effect of treatment by injection and theoretical aspects of face stability. It presents four case histories where shield and compressed air techniques were not used. It is concluded that, while ground treatment by injection can cause as many problems as it solves, it can still be effective in allowing safe tunnelling through marine deposits, so long as the limitations of the technique are recognized and taken into account.