ABSTRACT
A one-pass lining solution is being installed for the first time in the Middle East on the Doha South Sewer Infrastructure Project (Contract MTS-01), a deep tunnel sewer system developed by Ashghal (Public Works Authority) in the State of Qatar. With Jacobs as the overseeing Programme Management Consultant, the lining was designed and constructed by Bouygues Travaux Publics and Urbacon Trading & Contracting Joint Venture (BUJV). The one-pass lining comprises a 2.8 mm thick HDPE membrane on the intrados, forming the corrosion protection lining, which is mechanically bonded to a 300 mm thick steel fibre reinforced concrete lining to form a 3.0 m internal diameter tunnel. The HDPE membrane and concrete were cast in a precast segment factory operated directly by BUJV. The welding of approximately 250 km of HDPE membrane joints within the 16.2 km tunnel presented significant challenges in the restricted confines of a TBM backup gantry. The main challenges during the design and development of the one-pass lining are described by Najder Olliver & Lockhart (2017), who conclude that it has demonstrated its potential as a state-of-the-art solution. This follow-up paper presents the practical experience and main challenges encountered in the installation of the lining during construction.
