What Is Geotechnical Surveying?

Do you know what geotechnical surveying is? To many, this type of technical survey may be a mysterious process involving complex structures and equipment. In actuality, however, geotechnical surveying can be simply broken down into its most essential components: the investigation of soil, rock and other earth materials to define their properties for engineering purposes. From performing subsurface investigations for large-scale civil works projects to aiding with foundation preparation for buildings and homes – it’s no wonder why so many around the world rely on professional geotechnical surveys to complete both private and public works. In today’s blog post, we’ll explore just what goes into this kind of work so that those interested in or involved with geotechnical surveys gain a better understanding.

What Is Geotechnical Surveying?

Geotechnical surveying is a crucial element in the process of constructing buildings and developing land. It involves the investigation of the physical, mechanical, and chemical properties of soil and rock underlying a construction site to determine its capability to support the planned structure.

The Purpose Of Geotechnical Surveying

Geotechnical surveying aims to provide the necessary data for engineers and designers to understand the site’s geology and soil composition, determine potential issues such as soil settling and landslides, and ensure that the foundation structure can withstand the site’s geological conditions. This data can then be used to design and construct a safe and stable foundation for any structure that is to be built on the site.

The Phases Of Geotechnical Surveying

Geotechnical surveying is typically conducted in several phases and involves a variety of methods and techniques. The first phase is usually a site reconnaissance during which surveyors can evaluate the site’s physical characteristics, such as drainage patterns, vegetation cover, and landforms. They can also note any visible evidence of subsurface geologic and hydrologic conditions, such as exposed rock outcrops or water seepage.

The second phase involves drilling boreholes into the soil and rock to obtain soil samples and rock cores. This process helps geotechnical engineers to determine the soil’s properties, such as its density, composition, and strength, which will inform the design of any proposed structure. The boreholes also help to identify any potential issues that could impact the site’s stability, such as soil instability, ground movement, or the presence of groundwater.

Geophysical surveys are also conducted to map the subsurface geological features and understand the soil and rock characteristics in greater detail. This includes the use of instruments that can measure the density, electrical conductivity, and magnetic susceptibility of the soil and rock.

Who Conducts Geotechnical Surveying?

Geotechnical surveying is a highly specialised field requiring a range of skills, including geological knowledge and engineering expertise. Geotechnical engineers must have extensive training and experience in the physical sciences, such as mathematics, physics, and chemistry, to understand the complex natural processes that govern soil and rock behaviour.

What To Look For In A Geotechnical Engineer

When seeking out a geotechnical engineer, it is important to look for someone with a strong background in engineering, geology, and environmental science, who can provide a comprehensive understanding of site conditions and potential risks. A geotechnical engineer should also be equipped with excellent problem-solving skills, good communication and teamwork abilities, and the ability to evaluate and make recommendations on site-specific solutions. Additionally, a qualified geotechnical engineer should have the necessary professional licensure and certifications to ensure the highest level of expertise and competence.

Enhanced Safety For All Involved

By conducting a comprehensive geotechnical survey before construction, construction teams can ensure that a site is safe and structurally sound. This approach can also save time and money by identifying potential issues before construction begins, allowing for adjustments to be made to the design and protect against potential damage. It may also be a requirement of local government to complete a geotechnical survey before certain types of construction projects to ensure they are being done safely.

Geotechnical Surveying FAQs

What Are The Different Methods Used In Geotechnical Surveying?

Geotechnical Surveying commonly involves a range of techniques such as borehole drilling, soil sampling and testing, geophysical surveys, ground-penetrating radar, and topographical surveys. The method used depends on the geological characteristics of the site and the nature of the proposed development.

How Long Does Geotechnical Surveying Take?

Geotechnical surveying typically involves a detailed examination of the soil, rock, and other subsurface materials in a specific area, and the amount of time required to complete such a survey can vary greatly depending on the scope and extent of the project, but it usually takes several weeks to a few months to complete a comprehensive geotechnical investigation that includes drilling, sampling, testing, and analysis.

How Much Does Geotechnical Surveying Cost?

The cost of geotechnical surveying can vary depending on a variety of factors, such as the size and complexity of the project, the scope of work required, and the location of the site, but on average it can range from $500 to $5,000.

What Are Some Potential Findings Of Geotechnical Surveying?

Geotechnical surveying can yield valuable information regarding soil composition, stability, moisture content, and other factors that could impact the success or safety of a construction project. The findings of geotechnical surveying may also reveal potential hazards such as sinkholes, landslides, or underground water sources that could cause significant damage or delays if not properly addressed. Additionally, geotechnical surveying can provide insight into the environmental impact of a construction project and inform decisions related to site preparation, excavation, and foundation design.


In conclusion, geotechnical surveying is essential in ensuring the safety and stability of any construction project. Without proper geotechnical surveys, structures may be at risk of subsidence, landslides, and flooding, resulting in costly damage, injuries, and even fatalities. Professional geotechnical surveys should be conducted by trained and experienced geotechnical engineers, utilising recognised and proven methodologies to provide the most accurate and reliable data on the subsurface geology, soil and rock behaviour, and groundwater conditions at a site. With a thorough and detailed geotechnical survey, construction teams can construct stable and structurally sound foundations, and protect against potential issues, allowing projects to be completed with confidence and safety.

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