Road Moderate impact Ground improvement in shallow tunnel section, comprehensive real time monitoring strategy Rail Negligible impact: Impact Management: monitor and existing lines as required Flinders Street Station lines Trams lines Negligible impact: - St. Kilda Road Moderate impact: Ground improvement in shallow tunnel sections St. Kilda Road (near Wadey Street and Comprehensive real time monitoring CityLink crossing) strategy Utilities Negligible impact - Existing CityLink Preliminary Condition survey and monitoring of the tunnels assessment results CityLink tunnels prior to and during the found the change in excavation and construction of stress in the existing Melbourne Metro tunnels would be concrete lining caused required. An appropriate management by Melbourne Metro plan would be required that documents excavation would be acceptable stakeholder criteria for within the strength potential cracking and a predetermined capacity of the lining program for undertaking any potentially required minor repairs. After There is a risk of construction of Melbourne Metro aesthetic cracking in tunnels is completed, the CityLink the unreinforced tunnels should be inspected and, if secondary lining. As required, new cracks sealed during a the linings are regular maintenance closure. unreinforced, cracks would not pose any Detailed assessment of impact on structural capacity or CityLink tunnels durability risk Swanston Street Negligible to minor impact - Bridge (between Princes Bridge and Flinders Street) Princes Bridge Minor impact Completion of current site investigation works Strict control on TBM operation. Further analysis at detailed design stage Alexandra Minor impact Strict control on TBM operation. Avenue retaining Further analysis at detailed design with walls the benefit of pre-construction settlement monitoring data
Road Moderate impact Ground improvement in shallow tunnel section, comprehensive real time monitoring strategy Rail Negligible impact: Flinders Street Station lines Impact Management: monitor and existing lines as required Trams lines Negligible impact: St. Kilda Road - Moderate impact: St. Kilda Road (near Wadey Street and CityLink crossing) Ground improvement in shallow tunnel sections Comprehensive real time monitoring strategy Utilities Negligible impact - Existing CityLink tunnels Preliminary assessment results found the change in stress in the existing concrete lining caused by Melbourne Metro excavation would be within the strength capacity of the lining There is a risk of aesthetic cracking in the unreinforced secondary lining. As the linings are unreinforced, cracks would not pose any structural capacity or durability risk Condition survey and monitoring of the CityLink tunnels prior to and during the excavation and construction of Melbourne Metro tunnels would be required. An appropriate management plan would be required that documents acceptable stakeholder criteria for potential cracking and a predetermined program for undertaking any potentially required minor repairs. After construction of Melbourne Metro tunnels is completed, the CityLink tunnels should be inspected and, if required, new cracks sealed during a regular maintenance closure. Detailed assessment of impact on CityLink tunnels Swanston Street Bridge (between Princes Bridge and Flinders Street) Negligible to minor impact - Princes Bridge Minor impact Completion of current site investigation works Strict control on TBM operation. Further analysis at detailed design stage Alexandra Avenue retaining walls Minor impact Strict control on TBM operation. Further analysis at detailed design with the benefit of pre-construction settlement monitoring data
MMRP_Chapter-19_Ground-Movement.docx