Category: Infrastructure
Project: Bunbury Outer Ring Road Stage 2
Client: Main Roads
Project value: $133 million
Timeframe: April 2012 – June 2013
Background
The $133 million Bunbury Outer Ring Road (BORR) is a planned Controlled Access Highway linking the four major highways radiating from Bunbury on the outer edge of the City (namely the Perth Bunbury Highway, South Western Highway, Boyanup Picton Road and Bussell Highway) to the planned Bunbury Port Access Road.
The concept alignment for the road linked the Perth Bunbury Highway north of Bunbury to the Bussell Highway south of Bunbury over a distance of about 19 km.
Harley Dykstra was appointed to the project, as a sub-contractor for Stage two, to construction company Fulton Hogan, to undertake the surveying and generate operational data for the development of this major arterial road.
The project included construction of 12km’s dual lane, roundabouts (which needed to accommodate Port traffic including heavy haulage) and bridges.
Aecom was the appointed engineers and provided preliminary designs to Harley Dykstra.
Challenges
This was a particularly difficult project for the following reasons:
- The project was awarded under a set budget and timeline and subsequently this placed immense pressure on sub-contractors appointed to service the contract. Throughout the process there were numerous design changes, which were required to still be performed within the contracted budget. Harley Dykstra was also required to produce a monthly report (within 48 hours of end of month) which then became the basis for Fulton Hogan’s financial reporting to head office as well as the basis for projecting expenditure for the following month. Despite this significant constraint, the quality of the construction works was not compromised.
- The project commenced in April and hence this meant that major construction was to occur over the winter months, over areas which were prone to flooding. This could have had a significant impact on the delivery of the project, which was being closely monitored by both State and Federal Government.
- The Bunbury Outer Ring Road crossed over both the Preston and Ferguson Rivers which had historically flooded over the winter months. As a preventative measure Harley Dykstra took into account these weather patterns and site conditions and consequently set up survey control in locations where they would not be impacted, ensuring the consistency of data and minimal down time. Despite this forethought, the flooding did impact on the project, and washed away parts of the constructed bridge abutments. However as Harley Dykstra’s survey control had not been impacted, the abutments were able to be reconstructed without further surveying works or delays.
- There were high tension power lines running over the construction site and four power poles that had to be relocated to accommodate the new ring road, which posed safety concerns for the project team.In particular because the land was low lying (prone to flooding) 3m of fill had been installed on site. This increased the possibility that equipment may be operated too close to powerlines before they were lifted. As a result Harley Dykstra had to undertake full survey pick-up of the poles and suspended power lines to ensure adequate space between the newly constructed road and the electricity network.
- The South West Hwy needed to have 1600m of road rebuilt, in order to integrate with the newly created ring road. This required ramping the South West Hwy by 1m in order to join the newly created roundabout as well as major roadworks, whilst the South West Hwy was still in use by motorists.
- The project also required the construction of two bridges simultaneously. Harley Dykstra had one bridge surveyor servicing and project managing all three bridges and in particular the installation of approximately 80 pilings. This involved ensuring that the ground levels were consistent across all the pilings, both prior and after installation. It was essential that many aspects of the bridge construction fell within the 3mm tolerance levels.
- Again the construction of the ring road was constrained by major utilities and in particular the Bunbury to Perth gas pipeline. The Harley Dykstra team was required to measure pot-holed mains as well as accurately set out the pipe’s location, to prevent any major crisis. With major roadworks of this nature, vibrating roller compactors are commonly utilized, however they could not be operated over the pipeline as it could create gas leaks and potential fires. As such it was essential that Harley Dykstra accurately pinpointed the location of the pipeline so that any potential emergency was averted.
- Finally due to the complexity of the project, Harley Dykstra was instrumental with the introduction of new technologies within the South West. Firstly, for the major intersections, the project managers chose to install 360mm of asphalt for its durability. Normally road works only require 40mm of asphalt. This then required four applications of asphalt at 90mm depth each time. After each layer of asphalt was installed, Harley Dykstra was required to survey the area so as to advise the team what level was required for the next application. In addition Harley Dykstra installed a central GPS base station, to ensure that all construction equipment eg graders operated from this central data set and hence automated the major earthworks.
Each month Harley Dykstra also reported to Fulton Hogan management in terms of levels and quantities handled in the due course of the project implementation.
In addition, throughout the duration of the 18 month project, there were numerous changes to the design and Harley Dykstra demonstrated a flexible approach which ensured the project was delivered on time.
Furthermore the company allocated 3-6 full time surveying teams to the project both in the site office and also in the field. Despite difficult and grueling work conditions Harley Dykstra maintained a consistency in staff which was also a major contributor to the project’s success.
Outcomes
Despite onerous conditions and the complexity of the project, the Bunbury Outer Ring Road was delivered within the proposed 18 month timeframe.
In particular Harley Dykstra’s perseverance and ability to demonstrate strategic foresight was a major asset to this project and the team overall. The staff’s excellent rapport and communication skills also guaranteed positive working relations with all members on the project team for the duration.
This project demonstrated Harley Dykstra’s expertise and sound knowledge of surveying and project management, which ensured that the project was delivered on time and as per the scope of works.
