Advanced Design and Construction of Marine Cut & Cover ELS Tunnel Cofferdam

The most challenging aspect of the CKR-KTW Contract is the construction of maximum 35m deep Underwater Tunnel (UWT) submerged in Kowloon Bay which is a typhoon shelter with marine constraints from several stakeholders such as Hong Kong China Gas requiring 60m wide navigation channel for refueling tankers, Kowloon City Ferry Pier (AMO Grade 2 Historic Structure) operations for public ferry service and the marine traffic impact to Kowloon Bay. To overcome the substantial adverse impact to the environment and marine traffic of Kowloon Bay area from the conforming scheme of full temporary reclamation, an optimized scheme was employed for the marine cut & cover ELS cofferdam using only partial temporary reclamation. The use of this advanced design and construction method not only provided robust structural design with water-tight cofferdam, it also resulted in substantially less cost, construction risks / time and reduced disturbance to marine environment and traffic at Kowloon Bay due to substantially less temporary reclamation required.