Edithvale, Chelsea and Bonbeach – early site works
21 Nov 2019
Early geotechnical investigations help us understand important ground conditions and locate underground services across the project area.
So far in 2019, we’ve undertaken a range of preliminary geotechnical investigations in Edithvale, Chelsea and Bonbeach.
Each level crossing site is unique, and these initial site investigations provide valuable information about existing underground services and various ground conditions, including soil types and groundwater locations.
What are geotechnical investigations?
Geotechnical investigations provide important information about the physical properties of soil, rock and the water table around each level crossing site.
We also locate services around the level crossing sites, such as electricity, gas, water and telecommunications.
Before we can begin to design earthworks and foundations, we need to understand these ground conditions at each site.
How are geotechnical investigations carried out?
A drill rig is used to bore holes and take soil and rock samples. The bore holes measure 100 millimetres in diameter and are drilled as deep as 40 metres.
The samples are taken to a laboratory and analysed to determine soil strength, composition, water content and other characteristics.
Groundwater monitoring wells are installed in a series of boreholes to allow ongoing monitoring of groundwater levels.
Samples are taken to determine existing underground water quality, which can influence the design. Prior to this, a desktop groundwater model is developed.
More bores will be drilled during the next phase of geotechnical testing to inform the detailed design.
Soil samples taken during a geotechnical investigation on South Gippsland Highway, Dandenong
How does this affect me?
We will notify nearby residents and traders of upcoming works and any changes to how you move around your area. Geotechnical works involve a drilling rig and truck and are generally undertaken during regular construction hours of 7am to 6pm Monday to Friday and 7am to 1pm Saturdays.
While the works are not usually disruptive, some machinery noise may be noticeable.
Traffic and pedestrian management are put in place to help people and vehicles move through the area safely.
Geotechnical investigations provide valuable information about different ground conditions.
- Details about type and bearing capacity of soils.
- Any other geotechnical issues, including variability in ground conditions. For example, some locations along the Frankston line have been identified as having acid sulphate-rich soils, which can lead to certain environmental impacts if not managed properly.
- Location of existing groundwater systems and water table depths.
- Understanding the complex relationship between groundwater systems and local ecology.
- Locations of all underground services near the level crossing removal sites, such as electricity, gas, water and telecommunications.