Logan Enhancement Project

Background

The $512 million Logan Enhancement Project was Queensland’s first Market-Led Project to be approved and was a project that was driven by Transurban Queensland to improve essential congestion spots whilst providing enhanced connectivity between key major roads. This enhancement project would also further improve the Queensland economy by generating over 1.4 Billion over the next 30 years. Furthermore, this project hopes to enhance safety for drivers as well as reduce travel time and vehicle operating costs.

To learn more about this project, click here.

With the Logan Enhancement Project focusing their upgrades on the two major interchanges, two critical erosion and clarification projects were introduced. As the construction organization (CPB Contractors) placed focus on controlling areas that were susceptible to erosion and on the release of sediment into the natural environment, these two projects were imperative to the success of the overall project. With the upgrades to the interchanges and roads located in high traffic environments, meticulous planning was required for the two projects to not only ensure regulations and standard were met, but to also ensure potential health, safety, and environmental risks were identified, managed, and mitigated.

Challenges

As this project was completed between live traffic environments and surrounding woodlands, it was determined that sediment basins were required to capture the constant overflows of sediment and debris occurring from the large open construction areas and traffic. Furthermore, these overflows collected in the sediment basins were indefinitely determined to be harmful to the natural environment if they were to be released without first being treated.

In addition, the natural environmental constraints of the enhancement project would deliver various eroding obstacles (more than 400,000 m2 or 40 hectares of an area) to the design and development of the interchanges. These erosion issues occurred at the major interchanges and were especially visible on the slopes that create the new ramps for the entries and exits of the connecting motorways/ highways. With these slopes potentially becoming detrimental to the state of the new interchange if erosion and landslide were to occur, it was imperative that the erosion was controlled during construction to ensure the safety of construction workers and potential nearby road users. Furthermore, as the diverse soil types surrounding these large open construction works made erosion highly susceptible and even more possible, there was a greater necessity to mitigate the potential of erosion.

Solutions

Due to the immense size of the project, the GRT team would provide an area assessment on the projected enhancement and upgrade to the existing roads to determine the most suitable product/s considering both the environmental and economic impact this product may potentially develop after application. While it was determined that the best methodology of controlling erosion was to stop erosion at the source and not have it occur in the first place, this strategy was deemed difficult due to the magnitude of the entire Logan enhancement project. Therefore, it was determined that while GRT would strive to stop erosion at the source, sediment basins would be utilised to catch the potential overflow that would arise from the large open construction sites.

This strategic decision made GRT: Enviro-binder the recommended product for the erosion control of the Logan Enhancement Project as it:

• Followed the ideal of “STOP EROSION AT THE SOURCE – DON’T CATCH SEDIMENT”
• Provided exceptional erosion control immediately on drying.
• Met the strict environmental criteria imposed by the Transurban Queensland and a partner company, CPB Contractors.
• Required minimal maintenance, unlike conventional methods.

GRT Enviro-binder is a drying polymer emulsion sprayed on or worked into the surface of rail embankment to provide a waterproof, durable, surface that prevents erosion. 

In order to release the captured overflows from the sediment basin into the natural environment, the basin overflows are required to be treated first. GRT: CC, GRT’s most advanced concentrated polymer coagulant, was the recommended product as it:

• Clarified the contaminated water for release into the environment.
• Met rigorous environmental standards (ISO 9001 standards)
• Did not change the pH of the water, unlike other commercial concentrated coagulants.

Benefits

The GRT: Enviro-binder delivered high performing results that were expected from the product:

• Provides cut and embankment batter protection.
• Eliminated the need for sediment fences onsite.
• Minimal soil preparation for production application.
• Waterproof product; not affected by high rainfall or storm seasons.
• Cost-effective results.

The GRT: CC treated sediment basins also delivered low cost, effective results that were expected from the product:

• Only required 3750 litres of GRT product to treat up to 750 million litres of contaminated water (based on dosage rates of 5 litres of product to 1 million litres of contaminated water).
• Easy to handle water clarification product unlike other commercial products, like Gypsum.
• Cost-effective treatment for sediment basins.