Managing Ground Movement Impacts For Australian Urban Road Tunnels

Road tunnels in Australia involve underground construction with the potential for substantial impact to both surface and underground third-party assets. This paper looks at lessons learnt from recent and current Australian road tunnels in terms of stakeholder consultation and best practice for this process.

Road tunnels in Australia are generally delivered under a model where it is the design and construction contractor’s responsibility for undertaking the ground movement impact assessment. As a minimum this requires consultation with affected third party businesses, property owners, utility owners and road/rail authorities.

Contractual obligations may require contractors to consult with affected parties and receive formal approval prior to construction commencing. Affected parties will often not have experience or resources to engage in these processes and, therefore, the requirement for consultation and/or approval of the ground movement impact assessment and potential mitigation measures can put the construction programme at risk.

This paper will investigate the following in more detail:

• Ground movement design assessment approach
• Unknown conditions of third-party assets
• Parties requirements for assessment
• Monitoring of third-party assets and trigger levels
• Contractual obligations of the contractor
• Recommendations for future Australian road tunnelling projects