The Ringarooma Bridge on the Tasman Highway near Moorina in Tasmania’s north-east recently secured its place in Australian road and bridge safety history – becoming the first bridge in Australia to feature the innovative new DOLRE Low Stress Parapet System. The new DOLRE ‘Regular’ barriers not only provide an aesthetically pleasing barrier solution that complies with Australian Standards and has been ASBAP approved, they also provide life-saving MASH TL4 rated protection for road users, while at the same time delivering unmatched protection from damage to the bridge deck and structure during an impact.
Located on the Tasman (A3) Highway some 11 km east of Derby, the Ringarooma River bridge near Moorina is one of three bridges over the river between Launceston and St Helens on Tasmania’s north-east coast. Despite its remote location, strong growth in tourist traffic (the area is widely regarded as one of Australia’s premier mountain biking, adventure tourism and eco-tourism destinations), combined with the heavy vehicle traffic associated with the region’s timber, forestry and agricultural sectors, is placing a significant strain on the region’s ageing bridge infrastructure.
With that in mind, remediation works are being carried out on a number of key bridges across the region to increase load-carrying capacity and safety.
Remediation works on the Ringarooma River bridge near Moorina were carried out by Tasmanian civil infrastructure specialists BridgePro Engineering Pty Ltd. This included bridge strengthening works, application of a new wearing course, and installation of the DOLRE ‘Regular’ (TL4) Low Stress Parapet System.
As well as providing outstanding protection for road users, DOLRE’s ground-breaking design also helps to minimise the risk of damage to the bridge deck by restricting the energy from a vehicular impact to a fraction of the capacity of the bridge deck. This unique capability enabled the DOLRE barriers to be installed along the bridge kerbs without the need for any additional reinforcement or strengthening works.
The Ringarooma River bridge project included the installation of some 35 metres of ‘DOLRE Regular’ (TL4) barrier along each side of the bridge, together with the installation of off-structure barriers on both sides of the bridge. The off-structure barriers include DOLRE’s purpose-designed TL4-rated transitions, which connect the DOLRE barrier to a section of TL4 Thrie-Beam barrier. These TL4 Thrie-Beam barriers subsequently transition to TL3 W-beams with TL3 end terminals.
The DOLRE barrier, DOLRE transitions and the Thrie-Beams create a continuum of MASH TL4 protection for road users onto and across the bridge structure. Thus, there is an engineered continuity of MASH TL4 protection on either side of the DOLRE Regular traffic barrier.
For further information on the DOLRE Low Stress Parapet System, visit: https://dolre.com.au/