STABILISATION & DRAINAGE FOR REGENCY ROAD TO PYM STREET

PROJECT DESCRIPTION

The Regency Road to Pym Street (R2P) Project is the latest stage in the plan for a North-South corridor through suburban Adelaide, providing uninterrupted traffic flow in and out of the CBD and inner suburbs. The project comprises an at-grade motorway from the existing motorway to the north, an overpass over Regency Road; and an at-grade motorway from Regency Road to Pym Street, transitioning to the existing lowered motorway to the south.

This project has been one of the first in South Australia to incorporate the contract sustainability criteria that satisfies Infrastructure Sustainability Council (ISC); an Australian organisation that ensures all infrastructure projects deliver social, cultural, environmental and economic benefits. ISC’s mission is working with key industry players and partners, providing lead advances in policy, standards and specifications for low carbon, resilient, and inclusive infrastructure.

OUR SOLUTION

The R2P project overpass structure was designed and built comprising reinforced earth ramps leading to an overpass steel box beam superstructure. The R2P Alliance team asked Geofabrics to provide various products for drainage and pavement stabilisation work, in line with their ISC compliance requirements. We were able to satisfy our clients requirements with our new range of sustainable Bidim Green and Megaflo® Green.

Bidim® Green and Megaflo Green were installed in sub soil drainage lines along the reinforced earth walls and adjacent pavements leading to the overpass structure. Subsoil drainage provides stability and performance for pavements and walls by ensuring pavements are drained and dry. GlasGrid® was also selected as part of a standard treatment for reinforcing asphalt. It was installed between asphalt layers and placed 50mm below the finished surface.

In a South Australian first for this type of application, Concrete Canvas® was applied for erosion control on an exposed embankment, providing cost effective and long-life protection. It was supplied in an 8mm thick ‘concrete blanket’; anchored at the top of the slope with pegs and installed using a deployment frame. Concrete Canvas overlaps and is joined with adhesive sealant and stainless-steel screws to provide a contiguous surface protection layer.

PRODUCTS USED

Bidim® Green Non-Woven Geotextile

• Premium non-woven geotextile made with a combination of Australian recycled PET and virgin plastic material
• Used in the construction of roads, railways and embankments where ground is soft and unstable
• Separates soft ground from fill material, providing filtration for drainage, increasing the life span of the road and reducing long-term maintenance costs

Megaflo® Green Socked Slotted Drain Pipe

• Perforated HDPE core provides dimensional stability and field-proven structural strength for quick and effective subsurface drainage
• Slim 40mm wide profile permits faster and more cost-effective installation in a narrower trench
• Has twice the inflow capacity and can drain water in less than 60% of the response time compared to 100mm round pipe

GlasGrid® Asphalt Geogrid

• Fiberglass grid is applied between the levelling and surface courses of asphalt
• Designed to deflect crack stresses horizontally and dissipate stresses in asphalt layers
• Helps retard cracking from reflecting through a new asphalt overlay to the surface
• Self-adhesive application allows for quick installation

Concrete Canvas® Geosynthetic Cementitious Composite Mat (GCCM)

• A flexible, concrete impregnated fabric that hardens when hydrated to form a thin, durable, waterproof and fire-resistant erosion control layer - it is the original concrete on a roll