Sydney Chapter

Lane Cove Tunnel Retaining Structures

Paul Hewitt, Parsons Brinckerhoff

The Lane Cove Tunnel connects the M2 Motorway at North Ryde with the Gore Hill Freeway and the Pacific Highway at Artarmon. Design and construction involved about 70 retaining structures which included braced and anchored bored pile walls, soil nailing, reinforced soil wall systems and post-tensioned cantilever walls. Significant challenges related to restricted site access, the need to minimise construction impacts, a tight design schedule, and stringent settlement and angular distortion criteria.

Rigorous assessment of the effects of new construction on existing structures and construction safety utilised advanced numerical techniques to model ground-structure interaction. This talk discusses various geotechnical issues affecting design and construction, how the design was implemented in the field, and documents results of performance monitoring.

Monitoring data indicated the pre-construction geotechnical models and design parameters were appropriate. The suitability of the adopted wall construction techniques for the site conditions was demonstrated through the successful construction and performance of the works.

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