Gungahlin Drive Extension – Packages A and B

Package A - Aerial Photo

Project Location: Gungahlin Dr, Belconnen, ACT
Client: Roads ACT
Client’s Representative:
Superintendent: Maunsell
Superintendent’s Representative:
Project Start Date: September 2005

Description:

The Gungahlin Drive extension is an arterial road upgrade, connecting the northern section of Canberra to the Tuggeranong Parkway in Canberra central, a distance of 9km. The FHJV is an unincorporated partnership between Canberra Contractors, Guideline ACT and Woden Contractors. The project comprised  two separate contracts GDE A and GDE B.

GDE A – Scope of works:

  • 7 km of 2 lane arterial road
  • Bulk earthworks of 900,000m³, 200,000m³ to spoil, blasting of 20,000m³ rock
  • 1 D&C in-situ balanced cantilever post-tensioned concrete bridge over Belconnen Way
  • 2 precast prestressed concrete super tee bridges over Ginninderra Dr and Ellenborough St
  • 2 precast concrete bridges at Aranda
  • 5 reinforced concrete arch underpasses
  • Reinforced soil walls to all underpasses and bridges

    Package B

  • Soil nail walls in the Aranda precinct

GDE B –scope of works:

  • 3.5 km of varying width interconnecting roads joining the GDE with Parkes Way, William Hovell Drive and Tuggeranong Parkway.
  • Bulk earthworks of 250,000m³ with approx 50,000m³ of blasted rock.
  • Demolition of the existing 3 span post-tensioned Acacia Inlet Bridge.
  • 1 precast super tee bridge
  • 2 precast concrete arch bridges
  • 2 void slab post-tensioned concrete bridges
  • 1 ‘upside down’ post-tensioned concrete bridge
  • 3 box culvert underpasses with cast in-situ patterned concrete wing walls
  • Approx 2,500m² of reinforced soil walls to various bridge structures
  • Approx 1,500m² of soil nail walls at deepest cutting

Discussion:

Gungahlin Drive Extension (GDE) is a 9 km arterial road linking the Barton Highway to the Tuggeranong Parkway at Glenloch Interchange. The project comprised two separate contracts GDE A (7km road + 10 bridges and underpass structures) and GDE B (3.5 km of interconnecting roads + 9 bridges and underpasses at Glenloch Interchange) both awarded to the FHJV.

The FHJV is an unincorporated partnership between Canberra Contractors, Guideline ACT and Woden Contractors where each company is jointly and severally liable for the projects that FHJV undertake. It was agreed that each of the parent companies did roughly 1/3rd of the work.

GDE A was carried out in three distinct sections with one overall earthworks package. The three sections were controlled by three section managers which all reported to the PM.

GDE B was successfully tendered by FHJV in March 2006. The agreement was for the three parent companies to carry out about 1/3rd of the plant and labour

Package B - Arch Bridge

components of the work.

There were many areas of technical complexity that required specific input, some of these are listed below.

  • Construction of the in-situ balanced cantilever bridge at Belconnen Way- a technique relatively new to Australia and not used before in the ACT.
  • Traffic management, particularly in the Aranda section and at Glenloch Interchange where all work was carried out under traffic. The two way traffic diversion was developed by Guideline ACT SM in conjunction with the traffic consultant Hughes Trueman.
  • Blasting of unrippable rock in the Aranda section. FHJV enlisted the assistance of renowned blasting engineer Technik Consulting P/L to design the blasts to ensure that the predicted vibrations at the nearby ACTEW 900 dia watermain, 11kV and 132kV transmission lines and Aranda residences were within agreed limits.
  • Post tensioned ‘upside down’ bridge. This is an unusual structure and involved many hours of planning and preparation to ensure that the finished product achieved the required quality.