Jacked Box Versus Cut and Cover Technique for the Pedestrian Underpass Construction in Brisbane

摘要

Evaluation of the construction method used for the pedestrian underpass construction at IpswichrnRoad, Brisbane, Australia is presented in this paper. The pedestrian underpass was constructedrnthrough the existing railway embankment between Harrogate and O’Keefe Streets on the easternrnside of Ipswich Road. This underpass construction is part of the CLEM7 tunnel project (formerlyrnknown as the North-South Bypass Tunnel) which is the longest toll road in Australia at a total lengthrnof 6.8 km.rnThe jacked box construction technique was initially identifi ed as a preferred option during the tenderrnand concept design phases. However at the fi nal design stage, the cut and cover technique was selectedrnas this method can reduce the construction time and cost signifi cantly. The design and constructionrnteams effectively managed the challenges, complexities and risks associated with undertaking cut andrncover tunnel through the existing heavily utilised rail embankment. The on-site construction time forrnthe underpass using the cut and cover technique was reduced to less than 42 hours.