Due to our extensive experience working with correctional facilities, Woolacotts Consulting Engineers have recently been engaged to investigate options for the remediation and prevention of further slope failures at various correctional centre shooting range sites.
Corrective Services NSW identified challenges with the stability of existing earth mounds, constructed as ‘stop butts’, due to ongoing issues with erosion and inadequate topsoil vegetation at two of it’s facilities.
The Use of Stop Butts at Gun Ranges
A backstop, or ‘stop butt’, is an area behind the target into which a shot impacts after passing through the target. Outdoor ranges commonly use earth or sand butts, as these are highly effective materials for stabilising the high-speed impact of an object. Stop butts need to be of a sufficient height to capture the projectile passing through the target, as well as any ricochet that may occur from the projectile striking the floor of the target range fairway.
Stop butt height and structural durability are of high priority when complying with gun range safety requirements, which is why Woolacotts have been engaged to provide expert advice and consultation regarding the ongoing stability of these structures.
Innovative Materials Providing Thorough Design Solutions
Following the initial on-site assessment of the two correctional centre shooting range facilities, Woolacotts prepared a report outlining the causes of the existing slope failures and identified possible solutions to rectify the failing mounds. The use of a geocell/geoweb matt was ultimately incorporated into the design, to assist with erosion control as well as provide sufficient depth for topsoil to aid the growth of topsoil vegetation. Our Civil Engineering team recommended the use of the geocell/geoweb matt as this material can confine and stabilise soils that would otherwise be unstable under loading by utilising an interconnected honeycomb-like network.
The main design focus was how we could stabilise the surface erosion whilst providing a suitable ‘bullet blanket’ that would be subject to ongoing consistent shooting practice.”
– Justin Chirillo, Principal Civil Engineer Sydney Office
One of the gun range sites will be rectified as per the design recommended by Woolacotts. This range will be trialled over a 6 month test period, and if the site shows minimal negative impact or failure, the remaining on-site ranges will be upgraded using the recommended Woolacotts methodology.
This project adds to our growing justice and emergency portfolio, and demonstrates the expertise of our Civil Engineering team in providing innovative solutions to complex design challenges.
To learn more about our experience in the Justice and Community Infrastructure sectors, including other correctional center projects, visit our projects page here.