Geotech drilling is a site investigation technique that uncovers the physical properties surrounding a construction project. It involves evaluating the soil, rock, groundwater, and overall conditions within a specific depth and location.
Sonic drilling creates a continuous core sample of the in situ material with limited refusal and is able to drill in most lithologies and fill materials. It also offers superior hole logging for more accurate sample analysis.
The site analysis phase is a critical part of the design process. Taking a thorough approach at this stage will help to avoid issues that are costly or difficult to resolve in later stages of the design pr construction process.
The information gathered at this point needs to consider what is physically existing on and around the site, the way the site experiences sunlight and shade and any patterns that may exist. This information should also take into account what might be there in the future.
This will include things such as – Water supply – Underground and above-ground water pipes, manholes and access points. Electricity – Access points, transformers and power lines as well as the locations of any fire hydrants positioned on site.
Preparation for Foundations and Caissons
When building a new structure, you need to make sure the foundation is secure. Geotech drilling can uncover the integrity of the site before construction begins to ensure a safe and stable foundation that can handle the weight of your construction and prevent damage from earthquakes, floods, tornadoes, and other natural disasters.
Caisson construction involves watertight cylinders that are sunk into the ground and filled with concrete to create a base for a building. This construction method is often used for bridges and other large structures in deep waters or soft soils.
While constructing these foundations is relatively quick, they require more equipment than other methods, and can lead to higher construction, design, and maintenance costs. That’s why it’s important to have a geotechnical team that can evaluate the site and determine an adequate number, location, and depth of holes for the project at hand. This will help avoid costly delays and unforeseen issues down the road.
A soil profile is a cross-section view of the ground below the surface. It consists of layers, called horizons, that tell a story about the soil’s makeup, age and characteristics. Soil profiles are useful for farmers, ecologists, soil engineers, hydrologists and land use planners.
Each horizon is a distinct layer that reflects different factors in the environment that formed it. These factors include parent material, climate, topography and biological processes over time. A horizon may be absent from some soils, or its composition and properties differ from those of the surrounding horizons.
Most of these horizons can be distinguished from one another by their color, texture and chemical properties. A horizon that is wetter, for example, is darker and has more organic matter than a drier horizon. A horizon that is near saturation is labeled O, while the layer below that is called the A horizon. The B horizon is subsoil, and an R layer represents bedrock.
When it comes to constructing buildings, dams and infrastructure sites, geotechnical drilling is an essential phase of the process. It helps engineers decide how deep to place pilings and footings, or discover unusual soil conditions that need to be accounted for during construction.
Geotechnical drilling contractors use specialised machinery to drill holes into the ground and extract soil samples. These are then sent to our NATA-endorsed laboratory in Toowoomba to be analysed by engineers and geotechnical technicians.
There are several different types of geotechnical drilling, including standard penetration testing (SPT), cone penetrometer soundings and continuous cores. For hard-to-reach areas, sonic and rotary percussive drilling may be used. The latter is a more advanced drilling technique that uses vibration to dig into the site and offers limited refusal. It also takes more time and can be more expensive. However, it’s a good option for locating unsuitable rock and exploring the integrity of a site. It’s especially useful for examining underground geology and determining whether it is safe to build.