Combigrid®/Secugrid® Reinforcement for Pilling Platform

The Magic of Combigrid®/Secugrid® Reinforcement for Pilling Platforms on Poor Sand

Gallery House, Brisbane

Project Background

The $140 Million Gallery House project is Brookfield Residential Properties’ most luxurious project in Queensland and their seventh building in Northshore Hamilton. The project is located on an absolute riverfront site and includes “Gallery House One” with 169 apartments and approx. 1100m² retail in a 20 storey building with a single level basement, two storey podium and associated landscaping, and “Gallery House Two” with 150 apartments and approx. 990m² retail in a 19 storey building with a single level basement, two storey podium and associated landscaping.

Problem

As the construction site was adjacent to the Brisbane River, the existing poor sandy subgrade did not have the required bearing capacity to withstand the proposed 370kPa piling rig pressures to be applied during operations.

Solution

In order to achieve the required bearing capacity, Geoinventions Consulting Services (GCS) was engaged by Global Synthetics and Mainland Civil Pty Ltd to design a sufficiently thick working platform and provide design certification of the proposed Temporary Working Platforms (TWPs) to prevent any punching or bearing failures during the piling operations. GCS designed an 800mm thick platform using a Combigrid® 40/40 integrated geocomposite at the subgrade interface and a Secugrid® 40/40 geogrid within the platform. The geogrid component in Combigrid® provides reinforcement whilst the integrated geotextile component provides separation and filtration function.

Using Combigrid® and Secugrid® provided a considerable saving for the contractor by reducing the thickness of the platform compared to conventional working platform designs. This provided material savings and reduced the construction timeframe.

For further information contact amir@globalsynthetics.com.au