ABSTRACT
During a recent survey of contractors, consultants, designers and clients (UTRC, 1991) some 20 areas relating to the construction and maintenance of tunnels and underground structures were identified as causing concern and needing further investigation and research. The first two areas were the waterproofing and grouting of tunnels. As well as being interrelated, both have historically been troublesome; they have often caused construction delays and considerable overruns on costs, with solutions eventually being found at great cost, after long delays and with substantial lost construction time.
