RCA Australia completed all geotechnical investigation and design for the proposed shared pathway at Red Bluff, Eleebana on behalf of Lake Macquarie City Council. The pathway was opened in April 2010.
The new pathway is 450m long and was required to connect separate sections of existing pathway around Red Bluff. Approximately 380m of the pathway is over water and the investigation required over water as well as on land investigations.
The geotechnical investigation included the following:
- Developing a methodology for drilling over protected seagrass and obtaining Fisheries’ approval.
- Undertaking 10 bores (3 on land and 7 over water).
- Assessing acid sulfate potential.
- Recommending a preferred foundation system for the over water portion of the pathway.
- Undertaking work in a sensitive environment.
Newcastle Road (MR82) Intersection Upgrades
RCA has undertaken geotechnical investigation studies for the Roads and Traffic Authority (now Roads and Maritime Services) for the proposed upgrade of six intersections along Newcastle Road comprising intersections at Lambton, Jesmond, Wallsend and Cameron Park.
The investigations involved:
- visual appraisal and mapping of existing pavement condition;
- a total of 5.7km of Benkelman beam deflection testing;
- coring of 85 boreholes through existing pavement;
- excavation of 60 test pits;
- drilling of three cored boreholes;
- dynamic penetrometer testing;
- laboratory testing to provide parameters for input into design.
Specialised non-destructive potholing equipment was also used to provide accurate location of services for input into design for the proposed upgrade works. Owing to restrictions associated with closing lanes on Newcastle Road the majority of the investigation work was required to be undertaken at night.
Sophisticated Downhole Imaging Capability
RCA has significantly enhanced their downhole imaging capability with the purchase of a sophisticated borehole camera. The device is capable of inspecting bore and voids to depths of up to 200m and is able to be utilised in bores of minimum diameter of 70mm. The camera allows full remote control of pan and tilt from the surface and can be configured with a range of light sources depending upon the application. The device has found use in a range of applications including inspection of inclinometers, rock sockets (at a range of inclinations), bored piers and piezometers.
For abandoned mine workings the camera provides the ability to assess a range of mine characteristics such as overburden condition, void size and condition, and pillar location and condition. To date the camera has been used to inspect workings up to 100m depth in dry and submerged mines and has proved invaluable in assessing risks of development over old and current underground workings.