Ring Road over Moonee Ponds Creek: M80, Australia
Project Breakdown
As part of the Western Ring Road (M80) Upgrade Project in 2013, the carriageway required placement of a new barrier on the existing wide bridge deck to separate the traffic lanes from a surplus area to be used by pedestrians and cyclists.
The bridge deck had one-way cross fall sloping from right to left with grated drainage pits located adjacent to the left side bridge parapets. As a result, the new barrier had to allow unimpeded storm water runoff from the traffic lanes to collect at the drainage pits. The barrier also had to straddle the expansion joints at each end of the structure, so fixing the barrier to the deck was not an option.
The Challenge:
Initially, continuing the concrete barrier was proposed, but it became clear very early on that it could not be attached to the bridge deck and allow sufficient water flow underneath.
The VicRoads Technical Services Team proposed using a portable steel barrier on the bridge deck attached to the permanent concrete barriers installed on the roadway beyond the bridge expansion joints.
At this point, VicRoads (now the Department of Transport) sought the advice of Highway Care on a possible solution to meet the site requirements.
The Solution:
BG800 Portable Steel Barrier was recommended. To increase the unimpeded storm water runoff under the barrier, the barrier units were raised slightly. Nylon discs 50mm thick were attached to the pads under the barrier units to allow sufficient water passageway, including any possible debris build-up.
Using Nylon allowed for the barrier to deflect easily on impact by errant vehicles and any bridge movement.
“Using BG800 Portable Steel Barrier overcame these project specific issues, provided a safe barrier solution without the need for any alterations to the bridge deck. Further, it dramatically reduced the additional weight on the bridge.”
This was the first time that a temporary steel barrier, normally used at roadworks sites, was used as a permanent installation in Victoria. Approximately 150m was installed on the existing structure over Moonee Ponds Creek. It’s a novel treatment, unseen in these parts of the world.
The BG800 Portable Steel Barrier was later impacted by an errant vehicle. It is not known what type of vehicle was involved, but given the amount of deflection recorded, it was thought to be a large vehicle. No damage was sustained by the barrier. Some built-up debris under the barrier was cleaned away and the barrier was simply pushed back to its original alignment.
“The BG800 system proved to be an excellent and innovative solution at this unique location, where its installation was quick and simple.”
Richard Bortko, Senior Safe System Engineer, Victoria State Government Department of Transport