Description
| Sydney Metro City & Southwest – Geotechnical Data Report for Southwest Station and Corridor (SSC) Works – March 2017 |
This Geotechnical Data Report presents the factual results of the investigations carried out between Sydenham
and Bankstown for the Southwest Station and Corridor (SSC) works. The investigations in this report were
carried out within or, in the vicinity of, the Bankstown Line rail corridor. The locations included drilling adjacent
to Sydenham Viaduct, near to many of the existing rail bridges and close to most of the existing stations.
The investigation was carried out during the design development stage of the project. As the investigation
progressed, changes to the scope were made to respond to the ground conditions encountered and to respond
the design changes, including adjustments to the proposed dive structures.
This revision of the report includes laboratory testing previously not reported. The total number of investigations
locations completed below the existing ground surfaces is sixty eight. The boreholes were drilled to depths
below the existing ground surface of between 3 m and 40 m. All boreholes were drilled vertically using a
combination of truck, track and bobcat mounted drilling rigs.
In situ testing was carried out in boreholes including packer (water pressure) at three locations and downhole
imaging of the borehole walls at two locations.
Soil and rock samples recovered from boreholes were dispatched to laboratories for testing designed to
classify the materials, and to assess their strength, durability and deformation characteristics. The testing
included index tests, clay mineralogy determination and various triaxial tests on soils and unconfined
compressive strength tests with modulus assessment, shear box and petrographic analyses on rocks.
Standpipes (monitoring wells) were installed in some boreholes for the purpose of groundwater level
monitoring, sampling and testing. Groundwater monitoring reports are being provided separately, containing
the recorded groundwater levels and results of field and laboratory water testing after each monthly round of
monitoring.
Concurrent with the geotechnical investigation, samples were recovered for contamination testing. The results
of the contamination testing are presented separately in a Contamination Assessment Report (CAR).
At the time of this report all of the planned geotechnical investigations and contamination sampling for the
SSC works had been completed. The results of the remaining work laboratory testing will be presented in as
an update addendum to this interim report.
