NRT Cudgegong



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Project Overview

UEA was contracted to provide labour, plant and materials for the installation of various underground utility services. UEA relied on multiple installation methodologies to provide our client with a turnkey utility package around the newly constructed Cudgegong Train Station.

Scope of Works

Potable Water:
Approximately 1500 metres open cut and lay methodology in predominantly favourable ground conditions. The installed pipe ranged from DN200-250 DICL to several concrete encased MSCL type road crossings. There were a total of five connections to existing mains along Tallawong Road, Schofields Road and within the Cudgegong Train Station Precinct.

Recycled Water:
Approximately 1,300 metres open cut and lay of DN150-200 PVC pipe within a dual trench alongside the potable water line, including six connections to existing mains. Furthermore, these works included a 25 metre laser-guided GBM thrust bore across Tallawong Road, which involved the installation of a DN450 steel enveloper pipe and a DN200 PVC carrier pipe annular grouted within. Lastly, UEA designed and installed an 80 metre long OD250 bore using horizontal directional drilling (HDD) methodology in PE pipe across Schofields Road, allowing adequate clearance underneath dual 132kV electrical power feeders.

Waste Water (Sewer):
Approximately 300 metres open cut and lay, and 100 metres laser guided GBM thrust bore for a DN300 UPVC sewer line, connecting the new Cudgegong Train Station to the existing main after crossing Second Ponds Creek. The bore consisted of installing 100 metres of DN650 steel enveloper case, jacking this out with DN525 reinforced concrete pipe (RCP), followed by a DN300 UPVC carrier pipe on centralisers and grouting the annular gap. Eight maintenance pits were constructed in total, including two maintenance shafts and six DN1200 manholes (one being 8.4 metres deep). Due to the proximity of the job within the periphery of Second Ponds Creek and the surrounding vegetation, a prominent level of planning and care was taken to guarantee minimal impact on the environment.

Design

Design was provided to UEA through the client by a third party and Qalchek who were the Water Service Coordinators representing Sydney Water. Any design RFI’s and design changes met during construction were captured in Work as Constructed Drawings and worked through favourably to achieve suitable end goals. Through ongoing consultation with the client and designer, UEA provided the RW HDD bore design across Schofields Road, which was deemed unfeasible as a thrust bore.

Technical Details

All construction complied with Sydney Water’s “WSA 02-2002-Sewerage code of Australia_V4.0”, “WSA 03-2011-3.1 Water Supply code of Australia” along with “Technical Specification for Leak Tight Sewer Systems” and all other relevant Australian standards.

Challenges

  • Open cut excavation and trenching in zones of hard shale
  • Thrust boring completed under creek crossing in extremely weak siltstone, with a major emphasis on reducing environmental impacts to flora and fauna
  • Detailed sewer cutover procedure connecting to a live DN750 sewer main
  • Design and install 80 metres of RW HDD bore across Schofields Road, passing underneath dual 132KV power cables
  • Scheduling works within a fast paced, large scale infrastructure project with numerous work fronts
  • Complicated, PW/RW connections in unfavourable ground conditions, densely populated with multiple existing services