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NorthConnex

Engineering and Technical Opportunities

JDK was commissioned by the Client ABJV to work on the NorthConnex project, where the Client provided technical assistance for highway services, interchange structures, and associated transportation infrastructure to Sydney commuters and communities.

The NorthConnex project provides a multi-lane motorway that links the M1 Pacific Motorway at Wahroonga NSW to the M2 Motorway at West Pennant Hills, NSW. This project features twin motorway tunnels around 9 km in length and a height clearance of 5.30 m. The tunnels were constructed with three-lane capacity in each direction, including two current lanes and a breakdown pull off-lane.

A northern interchange was included at the M1 Pacific Motorway and Pennant Hills Road, including sections of the tunnel for on-ramps and off-ramps to facilitate access to and from the Pacific Highway. A southern interchange with the Hills M2 Motorway and Pennant Hills Road was added, including sections of the tunnel for on-ramps and off-ramps. Integration works included carriageway extensions and modifications. Infrastructure works included widening and lengthening bridges and viaducts and modifying local roads.

Project

NorthConnex

Client

LendLease Bouygues
Joint Venture (LLBJV)

Location

Sydney, Australia

Time Frame

April 2017 – September 2020

Budget

$3.70 billion

Project Highlights

Approach and Innovation

JDK carried out full time coverage on this project with a streamlined approach, from the initial systematic capture of geotechnical and geological information to the final installation of support for remediation.

The project scope was broken down into the following three stages:

Step 1

  • Third party geotechnical review and implementation of design
  • Geotechnical assessment of roof conditions
  • Rock fall remediation and prevention
  • Crack mapping, and geotechnical assessments pertaining to repair and remediation of finial lining
  • Water seepage mapping, remediation, and recommendations
  • Geological defect mapping, monitoring, and remediation
  • Geotechnical assessment and confirmation of ground conditions for support type design compliance
  • Permit to excavate and permit to tunnel (review and implementation) through poor ground conditions

Step 2

  • Permit to trench through poor ground conditions with a high defect frequency and weak rock mass
  • Review of electrical and water conduit installations across 40km+ of trenches within shale and sandstone rock
  • Third-party review of pad install and pile design for surface signs installed through pilling operations and bearing capacity analysis

Step 3

  • Review and mapping of the final lining installation
  • Identification and review of final lining for installation of strip drains, and crack remediation in accordance with the designer’s AGJV specifications
  • Inspections for geotechnical stability and adherence to temporary works design for excavations
  • Ad-Hoc recommendations of possible remediation methodology for excavations to the senior engineering management and temporary works teams

Value Added to Project

JDK were involved in the successful completion the NorthConnex project, adding value across key areas and meeting all stakeholders’ needs. The JDK team interacted with several Client teams across disciplines providing extensive geotechnical expertise to help manage and control tunnelling risk.

The implementation of monitoring controls was completed without any community complaints, client issues, or existing infrastructure damage. The project incorporated innovative data collection methods, which led to enhanced data quality and improved outcomes throughout the delivery process. The precise inferences of ground conditions enabled the client to allocate resources and maintain their deliverables schedule efficiently.

JDK completed all work safely, within budget, and on time while meeting the design and specifications of the contract. JDK is proud to have played a key role in developing critical infrastructure for the Sydney community.