CLIENT: Lend Lease – Tintenbar to Ewingsdale (T2E) Project
DESCRIPTION Tunnel Grouting and Soil Nail Wall Construction
The project scope consisted of testing the rock mass permeability of both St Helena tunnels, each 480m in length. This tunnel grouting work was completed by SSS prior to the installation of the tunnel final linings, including the waterproof membrane. The test data was then submitted to the client enabling them to calculate the need for grout curtain construction to control ground water.
SSS then constructed a soil nail wall which was 150 metres long by 7 metres high within previously disturbed ground. The drilling are consisted of very hard correctness removed and buried during a previous highway upgrade. Large scale grouting was required to consolidate the ground before drilling could continue.
Hollow Gewi bar soil nails up to 9 metres long were installed with a fibrecrete facing of 200mm thickness. The installation of a pedestrian walkway and hand railings was then constructed with no interruptions to highway traffic.
On completion of the soil nail wall, SSS was then engaged to commence contract grouting of the final concrete lining of the twin tunnels. This work consisted of two crews mixing and grouting the tunnel lining incrementally. SSS submitted a mix design for approval, conducted all quality testing as required and completed the project with LTI’s.