At the emergency support facility, underground support structures, also known as ground anchors, are required to allow construction to be undertaken safely.

Ground anchors are commonly used for underground construction activities in Victoria and across the world and will not physically impact existing residential buildings or infrastructure during SRL East works.

A ground anchor is a steel rod or cable which is inserted into a predrilled hole, fixed deep underground and tensioned to ensure the stability of the area so excavation can be undertaken.

Seven rows of ground anchors will be installed row-by-row for the emergency support facility's intervention and ventilation shaft. The anchors will be used to provide additional support to strengthen the ground during excavation and fit-out works of the shaft.

Once construction of the shaft is complete, temporary support from the ground anchors will no longer be required. The anchors will then be de-tensioned and left in the ground.

What this means for you

• Ground anchors will not impact existing buildings or infrastructure
• They are installed from within the site and no access to residential properties will be required during these works
• Ground anchor depths will depend on location, ranging from between 3.5 metres to 23.5 metres below the surface
• Low to medium levels of noise and vibration may be experienced during installation.

How we install ground anchors

Note: Drawing is indicative only

How are ground anchors installed?

1. We will dig out and excavate the soil to the required depth
2. Using a ground anchor drill rig we will drill a hole through the bored pile and into the surrounding ground. We will then install the ground anchor into this hole
3. We will fill the hole around the anchor with grout so the anchor is fixed into the ground
4. When the grout has hardened, we will tension the anchor to the pile. This will create stability for the intervention and ventilation shaft walls

This process will be repeated row-by-row seven times at deeper depths each time to install the ground anchors.