top of page

What's involved in a geological site investigation?

Geological site investigations are an essential part of civil engineering projects that involve construction, excavation, or alteration of the earth's surface. These investigations provide crucial information about the geological and soil characteristics of the site, which is necessary for the successful planning, design, and construction of any project.



Importance of Geological Site Investigations in Civil Engineering


Geological site investigations are critical in civil engineering projects as they provide essential information about the site's geology, soil, and rock formations. This information is used to determine the suitability of the site for the intended use and the design of the structures to be built. Geological site investigations also help to identify potential hazards such as landslides, sinkholes, and other geological hazards that could affect the stability of the structures.


The information obtained from geological site investigations is used to develop geotechnical reports that provide guidance on the design and construction of structures. Geotechnical reports include recommendations for foundation design, retaining structures, slope stability, and other critical elements of the project. These recommendations are based on the results of the site investigations and are critical for the successful completion of the project.

Techniques Used in Geological Site Investigations


Geological site investigations involve various techniques to obtain information about the site's geology and soil characteristics. The most common techniques used in site investigations include:

  1. Surface mapping: Surface mapping involves the visual observation and mapping of the exposed rock or soil layers on the site. This technique provides information on the site's geology, soil type, and the potential for geological hazards.

  2. Drilling: Drilling involves drilling boreholes into the ground and extracting soil and rock samples for laboratory testing. This technique provides detailed information about the site's geology and soil properties.

  3. Geophysical surveys: Geophysical surveys involve using instruments to measure the physical properties of the soil and rock layers beneath the surface. This technique provides information about the site's subsurface structure and can be used to identify potential hazards such as sinkholes or underground voids.

  4. Remote sensing: Remote sensing involves the use of aerial photographs and satellite imagery to obtain information about the site's topography, geology, and vegetation cover. This technique can be used to identify potential hazards such as landslides or flood-prone areas.

Factors Affecting the Selection of Investigation Methods


The selection of the investigation method depends on various factors such as the site's size and complexity, the intended use of the site, and the budget for the project. For example, small sites may only require surface mapping and drilling, while larger and more complex sites may require geophysical surveys and remote sensing.


The intended use of the site also affects the selection of investigation methods. For example, a site intended for the construction of a high-rise building may require more extensive investigations than a site intended for a single-family home.


Geological site investigations are essential in civil engineering projects as they provide critical information about the site's geology and soil properties. The information obtained from these investigations is used to develop geotechnical reports that provide guidance on the design and construction of structures. The selection of investigation methods depends on various factors such as the site's size and complexity, the intended use of the site, and the budget for the project. By conducting thorough geological site investigations, civil engineers can ensure the successful completion of their projects while minimizing potential risks and hazards.

bottom of page