Geogrid used in Greenfield Bridge Inn Road Upgrade

The Project

The Bridge Inn Road Upgrade project in Mernda aims to reduce congestion and improve traffic flow for motorists in Melbourne’s northeast. 

The scope of work includes extra lanes in each direction, upgraded intersections and new shared walking and cycling paths, with the main part of the project being the construction of a new bridge over the Plenty River. 

The Challenges

To build the new bridge, the contractor needed to create the site hardstand, car park and site area over existing greenfields without any excavation. Weak-saturated subgrade and heavy weather events had driven this decision, with extensive La Nina rainfall forecast for a long duration of the project. 

Of course, choosing to begin construction on a 16000 sqm green field site without excavation meant that subgrade improvement was critical. 

The contractor contacted Polyfabrics for a solution that would allow work to begin ASAP without heavy excavation required. 

Our Solution

The choice of Polyfabrics mastaGRID 4040GT composite geogrid with 200mm of 40mm crushed rock allowed the contractor to successfully construct a car park pavement directly over the green field site.

We were able to overcome the issue of the weak subgrade and low soil shear strength while still being able to construct the pavement on time and as per the design.

This resulted in huge cost savings who was able to save on additional excavation and bringing in imported fill. The carbon footprint of the project was reduced, delays were eliminated and the installation went smoothly with mastaGRID 4040GT composite geogrid being very easy to install on site.

This solution has since proved itself in the field throughout prolonged wet weather across much of Melbourne. With no waterlogged excavation to contend with, the project can press ahead despite the frequent rainfall. 

To find out how to get the best solution for your greenfield project, get in touch with the engineering team at Polyfabrics.