Helensburgh Rockfall Barrier, Sydney Trains

As part of a slope stability maintenance program, GSS were engaged to deliver Australia’s longest Hybrid rockfall Barrier in a 5 week period using difficult access drilling systems.

Many of the slope instabilities were associated with the presence of significantly large, fractured, or even detached rock boulders along the top edge of the cutting. The block features are likely to fail through sliding rather than bouncing. The cutting is up to 16m high, with the top 4m being vertical, and below that roughly 45 degrees.

There is a continuous flatter angled slope above. Hybrid barriers are typically constructed using an ETAG 027 rated rockfall barrier system with alterations made to the netting configuration to create a tail that can be draped over the ground downward of the structure.

GSS installed a Maccaferri hybrid rockfall barrier comprising of posts, anchors, steel wire rope, anchor plates, high performance mesh, and accessories.

At 422m, it is by far the longest hybrid Barrier in Australia.