ABSTRACT
Increasingly ambitious tunnelling projects are being undertaken throughout Asia in difficult geological conditions, sometimes in urban areas close to major structures. This paper addresses the need for better allocation of responsibilities and identification of engineering and contractual risks for such projects with particular emphasis on the need for ground and ground water control.
Methodology developed for qualitatively assessing geological and programme risks during construction of projects like the Athens and Singapore Metros, and recently applied for tendering for the Singapore Deep Tunnel Sewerage System and Guangzhou Metro Line 2 are presented together with specific recommendations to both Owners and Contractors for minimizing the frequency and impacts of such risks.
