Expect delays for controlled rock blasts near Pacific Highway at Dirty Creek this Friday
Department of Infrastructure and Regional Development communications officer Matthew Cropper has issued an explanation into the controlled rock blasting scheduled to take place at Dirty Creek as part of the Pacific Highway Woolgoolga to Halfway Creek project.
What is happening?
Controlled blasting is often used in road construction and other industries. Roads and Maritime Services engages contractors who are very experienced in carrying out safe blasting.
Each blast will be designed, conducted and monitored by experts to conform to strict guidelines and limits. Controlled blasting is the most efficient way to remove about one million cubic metres of rock and cut up to 45 metres deep into hills for the Woolgoolga to Halfway Creek project.
This is needed to create a more level road. A level road increases safety and reduces fuel consumption as well as noise from motor vehicle engines and truck braking. This rock will be used on the project reducing the amount of rock imported and the number of gravel trucks using the Pacific Highway.
Why is it happening?
Tests show rock in the new roadway in this vicinity is very hard and cannot be removed using machinery alone.
How do they blow it up? What do they use?
Blasting experts design a plan for the controlled blast. Holes are drilled into the hard rock by drilling rigs according to the blast plan. The explosive is placed into the holes and 'stemming' or small rock is placed on top of the explosive to contain the explosive and help shatter the rock.
How much rock they will blow up?
Friday's controlled blast will produce about 14,000m3
What is the actual design plan at Dirty Creek eg why are they blowing it up - is it an underpass etc?
There is a future interchange to be built in this vicinity north of the existing intersection of the highway and Range Road at Dirty Creek.