Lower Friction, Higher Velocity for Geelong Freeway

Project Name              Geelong Road Project – Little River Section
Location                       Princes Highway, Little River, Victoria
Client                           VicRoads
Civil Engineer              GHD
Project Manager          Leighton Contractors Pty Limited
Drainage Contractor    Alan Gray
Project Cost                 $74M
Completion Date          November 2002

James Hardie Products Used
4km of classes 1, 2, 3, 4, and 6 FRC™ rubber ring jointed pipe.

The Little River section is the longest of the four upgraded sections of the Princes Freeway upgrade, the second busiest road in Victoria, linking Melbourne and Geelong.

The project involved the reconstruction of 21km of freeway to increase capacity from two lanes in each direction to three lanes in each direction. Floodwaters crossing the existing Geelong Road previously cut the highway every five or so years.  Part of the Geelong Road upgrade was to increase the road’s immunity to floods to an Average Recurrence Interval of 30 years.

The design solution for flood immunity included 15 major crown unit stormwater drainage structures of varying multiple cell configurations. These were constructed and connected to a 375mm diameter FRC™ pipe with a length of 4km to provide an outlet to drain the major cross culverts after flood event storms.

Leighton Contractors’ Project Manager, Steven Knowles, says, “FRC™ pipes were chosen for their lower coefficient of friction, and ease of handling adjacent to the freeway and in trenches through rock, in depths up to 4 metres.”

GHD worked closely with the technical staff of James Hardie to arrive at the appropriate class for each length of pipe required at access pits; with the resulting arrangement a mix of class 1, 2, 3, 4 and 6 FRC™ pipes.

Tom Brock from GHD, stated “FRC™ pipe offered the project some advantages over steel reinforced concrete pipe with better hydraulic smoothness and hence velocities. With the velocity running full at a hydraulic grade of 1 in 500 is 1.02 m/s for FRC™ pipe, compared to 0.80 m/s for SRC, the expected flow velocity with FRC™ pipe is considerably better than with SRC.”

“FRC™ pipe offered technical benefits to the overall design solution that satisfied VicRoads performance requirements.” – Ray Bridges, Project Manager, VicRoads