South Road – T2T Geotechnical, Pavement and Contamination Investigation for the South Road Upgrade from Torrens Road to River Torrens

South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

3.7 km length of South Road between Torrens Road and River Torrens

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Image courtesy of DPTI

South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

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Image courtesy of DPTI

Excavations to 8-10 m deep required for grade separation at: – Grange Road – Port Road – Outer Harbor Rail Line – Possibly also Hawker Street

Approx 1.7 km long lowered road

South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

Subsurface investigations comprised: – 125 Geotechnical Boreholes (ranging up to 40 m deep) – 246 Pavement Boreholes (ranging up to 10 m deep) – 195 Dedicated environmental contamination boreholes

(ranging up to 6 m deep) – Total drilling length of all boreholes = 5.3 km – In-situ testing, comprising 72 CPT and 37 DMT – Geophysical Investigation – Groundwater Level Monitoring – Groundwater Contamination Investigation

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South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

Geophysical Investigation:

- Combination of Multichannel Analysis of Surface Waves (MASW) and Seismic refraction methods used over 17 profiles along the corridor

- Program conducted at night to minimise traffic noise

- Data processed and interpreted, to provide information on presence or capability of holding perched groundwater

- Correlated with geotechnical borehole data

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South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

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South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

Groundwater monitoring wells installed in 20 boreholes

– Piezometers installed with hollow auger drilling methods under environmental protocols along the corridor length

– Groundwater levels recorded when struck during drilling

– Periodic monitoring of groundwater levels for at least 1 year

– Groundwater samples collected for chemical analysis and contamination investigation

Historical groundwater well level monitoring – Up to 9 years of sporadic data for

some monitoring wells installed by URS in 2006

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South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

Seasonal variation in groundwater levels of typically up to about 400 mm over the last 12-18 months in groundwater wells installed during this investigation

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South Road – Torrens to Torrens, T2T

South Road T2T Geotechnical, Pavement and Contamination Investigation

Groundwater level variations of ~1.2 m over the last 9 years in historically installed groundwater wells monitored by DPTI and also URS during this investigation

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