Bulga – Haul Roads, Arches and Eastern Emplacement

Hunter Valley, NSW

Client: Glencore

Project Highlights

  • Installation of 70 20t arch segments and Spandrel wall segments over a three day rail shutdown (210 in total).
  • Bulk earthworks throughout an active mine site, managing interactions and mine wide traffic management plans.
  • Diversion of Nine Mile creek in two locations to allow construction of two new culvert crossings.
  • 60,000+ man hours LTI free.
  • Project co-ordination with four other contractors working in simultaneous operations.

Project duration of 12 months at a value of $21.8m.

Scope of Work

Construction of three arch bridges and new mine haul road for the re-alignment of Broke Road and associated dams.

Project completed ahead of schedule and under budget.

Robson was engaged to complete the following scope of works:

  • Construction of 3 concrete arch bridges;
  • Bulk earthworks, with over 550,000m3 of fill;
  • Construction of three mine water dams with capacity of 20ML, 30ML and 15ML respectively;
  • Construction of Helcore culverts ranging in size from 750mm dia. to dual 3300mm dia.;
  • Construction of three RE wall structures, using standard panels and oversized spandrels over active rail line; and
  • Service relocations – Hunter River raw water feed (DICL Pipe), and rail signalling.

 


 

Northern Water Dam

Bulga, NSW

Client: Glencore

Project Highlights

  • Use of geomembrane sealing system to the upstream face which is the first of its kind installed in Australia. This was a high risk activity that was installed using a rope harness system on a 2:1 slope and was completed without injury or accident.
  • Extensive erosion and sedimentation control measures installed along the existing creek bed including numerous temporary cofferdams, diversion drains and sedimentation basins. These measures ensured the works were protected during peak rain events.
  • The project was completed on time and within budget, with nil lost time injuries. 

Project duration of 12 months at a value of $15m.

Scope of Work

The purpose of the Northern Water Dam (NWD) is to provide water storage for dewatering of open cut coal mining pits. This will replace other water storages on the mine site that will, in the future, be removed due to mine expansion.

Robson was engaged to complete the following scope of works:

  • NWD Main Embankment – 16m high zoned earthfill embankment fitted with an exposed geomembrane sealing system (GSS) installed on the upstream slope;
  • Controlled Release System – Concrete encased steel pipework, a reinforced concrete energy dissipation structure;
  • Controlled Release Outlet Works – Rockfill-lined outlet channel and stilling basin;
  • Diversion Embankment – 12m high zoned earthfill embankment and spillway;
  • Diversion Channel – The diversion channel will bypass water around the north eastern side of the NWD; and  
  • Rail level crossing upgrade to allow construction traffic to safely access site.

 


 

Moolarben Coal Operations Dams Construction

Moolarben, NSW

Client: Yancoal

Project Highlights

  • Both projects were urgent infrastructure projects to the client. Acceleration was requested by client in order to facilitate mine expansion, this was completed successfully with a larger haul fleet.
  • Mixing of 45,000m³ clay liner with 2% gypsum & bentonite, placed, levelled and compacted to specification.
  • The client noted they were impressed with Robson’s ability to handover all Quality Assurance documents in a timely manner enabling the dams to be commissioned on time.
  • NIL environmental incidents or dirty water leaving site recorded.
  • Client complimented the team on overall quality of the build and collaborative spirit of the project despite several technical complications and condensed timeframe.
  • Client noted they were extremely pleased with the way Robson delivered a high quality product with all commercial issues handled in a cooperative and collaborative manner.

Project duration of 12 months at a value of $8.8m.

Scope of Work

Robson was engaged by Yancoal to construct two new Dams (Murragamba Dam & OC2 Brine Water Dam) at its Moolarben Coal Operations, located in the Western Coalfields of NSW.

Murragamba Dam entailed the construction of a 500ML dam for capture & containment of clean water from the Murragamba Creek Catchment.

OC2 Brine Water Dam entailed the construction of a 250ML clay lined water dam to facilitate the mines expansion.

Robson was engaged to complete the following scope of works:

  • Bulk earthworks;
  • Stripping and stockpiling of topsoil;
  • Embankment Construction;
  • Installation of geotextile and rock-lined batters;
  • Spillways and drop structure;
  • Concrete sill works including steel reinforcement
  • Diversion bunds and drainage; and
  • Dewatering.

 


 

Liddell Mt Block Rehabilitation

Hunter Valley, NSW

Client: Glencore Liddell Coal

Project Highlights

  • Aerial seeding successfully completed using a Helicopter. This method of rehabilitation was implemented due to the risk involved with the slopes of the mountain ranging from 3:1 to 1:1.

Project duration of 14 months at a value of $5m.

Scope of Work

The Mountain Block is a historical mining area approximately 7.3km north of current mining activities at Liddell Coal Operations where a hillside was mined and rehabilitated. Over time, a large section of the hillside landform has become unstable, with unsatisfactory vegetative cover

Robson was engaged to complete the following scope of works:

  • Establishment and maintenance of erosion and sediment control measures;
  • Bulk earthworks shaping to create final landform;
  • Construction of temporary access roads;
  • Installation of rock drains;
  • Spread topsoil / compost;
  • Amelioration of soil;
  • Apply revegetation; and
  • Installation of surface erosion protection and maintenance during vegetation establishment.

 


 

Bengalla Dry Creek Diversion

Hunter Valley, NSW

Client: Coal & Allied (BMC)

Project Highlights

  • Robson offered a practical approach to onsite design changes and minor alterations in a short timeframe without impacting the program.
  • The client’s representative stated that ‘CW1 was delivered safely, on time to the required quality with a high proportion of long term Robson employees.
  • Over 80,000 man hours worked with NIL Lost Time Injuries (LTIs) recorded.

Project duration of 11 months at a value of $17.6.

Scope of Work

The Dry Creek diversion consists of a 900ML clean water dam acting as a detention basin upstream of the coal mine.

The stored water will be released back into the environment at the southern extent of the mine site via a 6.5km on ground HDPE pipeline that is a combination of a pressure and gravity system. The project also included construction of approx. 6.5km of diversion levee which will divert clean water around the site and allow the mining operations expand to the west which will remove the existing dry creek.

This 47 week project consisted of five separable portions including:

  • Separable Portion 1 – Pump station pad, electrical station pad and surrounding road network;
  • Separable Portion 2 – Clean water storage dam including outlet pipe, spoil stockpile area, diversion drains and access roads;
  • Separable Portion 3 – Services corridor including the HDPE pressure and gravity pipelines;
  • Separable Portion 4 – Downstream works including culvert installations to Bengalla Road & Old Bengalla Road; and
  • Separable Portion 5 – Diversion levee.