Geotechnical Site Investigation
Prior to writing the Geotechnical reports, Geotechnical engineers carry out site investigations, testing the sites ground conditions.
The geotechnical engineer will undertake ground testing suited to the ground conditions encountered.
Two common in ground test methods are described below and it is likely that a combination of both tests will be used to test the soils.
Coarse grained soils
In coarse grained, granular soils, such as sands, in ground testing comprises of a Scala penetrometer testing.
Fine grained soils
In fine grained, cohesive soils, such as silts and clays (including Ash soils), in ground testing comprises of hand held shear vane tests.
Where sites require deeper testing greater than 5.0m begl, machine boreholes and other testing equipment may be required.
The results of the site investigation are summarised in the Geotechnical Report with development and foundation design recommendations.
A well-devised, specific site geotechnical investigation is a key requirement for good building performance and mitigates the risks of unsatisfactory ground performance.
The understanding of site soil conditions is an essential input into robust foundation solutions.
A ground investigation serves two primary purposes, by:
Providing data for analysis and design and reducing uncertainty about ground conditions, thereby reducing the risk of construction cost variations.
Recognise that site investigation is usually money well spent and is at a modest upfront cost compared to the cost of the proposed development.
Also, often an appropriate site investigation will lead to a more economic foundation design solution, reduce risk of project delays and reduce risk of post-development building performance issues, so the geotechnical report will pay for itself.
Use an appropriately qualified Geotechnical Professional to tailor the site investigation objective(s) to the project’s requirements and risks.