Understanding Geotechnical Services and Their Purpose

Geotechnical services hold immense importance in civil engineering and construction ventures. Their pivotal role lies in safeguarding the security, durability, and ecological soundness of infrastructure advancements.

This article ventures into the domain of geotechnical services, examining their scope, objectives, and critical role across diverse construction and engineering projects.

What Are Geotechnical Services?

The term “geotechnical services” refers to various engineering practices and techniques used to evaluate and comprehend the behavior of soil and rock under the surface of the Earth. These services mainly focus on the physical characteristics of subsurface materials as well as how they interact with the environment and man-made structures.

Geotechnical experts, also known as geotechnical engineers or geotechnicians, carry out geotechnical investigations and offer insightful information on the soil and rock conditions at a construction site. These investigations are essential for making informed decisions during the project’s design and construction phases.

The Purpose of Geotechnical Services

Site Characterization

One of the primary purposes of geotechnical services is to characterize the site’s subsurface conditions. Establishing an in-depth site profile entails taking soil and rock samples, executing numerous tests, and analyzing the results. This information helps engineers and architects understand the geological and geotechnical challenges they may encounter during construction.

Foundation Design

A solid foundation is essential for the stability and longevity of any structure. By employing geotechnical services like soil testing and settlement potential, geotechnical engineers can recommend the most suitable foundation type, whether it’s shallow foundations, deep foundations, or specialized solutions like piles or caissons.

Slope Stability Analysis

In projects involving slopes or embankments, such as highways, dams, or retaining walls, geotechnical services are crucial for analyzing and ensuring slope stability. Engineers evaluate the angle of repose, shear strength, and other geotechnical properties of the soil to prevent landslides or slope failures that could endanger lives and property.

Earthquake and Seismic Assessments

Geotechnical services are considerably more crucial in areas that are prone to earthquakes. The seismic susceptibility of the site is evaluated by geotechnical engineers, who then build foundations and structures that can withstand earthquake-induced ground vibrations. This requires assessing elements like the possibility of soil liquefaction and ground acceleration.

Common Geotechnical Services and Techniques

Depending on the project’s requirements, geotechnical services encompass various techniques and investigations. Some of the standard services and techniques include:

Soil Sampling and Testing

Geotechnical engineers take soil samples at various depths to evaluate characteristics, including moisture content, density, particle size distribution, and shear strength. These data points are used to classify the soil and understand how it behaves under load.

Hydraulic Profiling Tool (HPT)

The Hydraulic Profiling Tool (HPT) is a specialized geotechnical instrument employed in environmental and hydrogeological studies to delineate subsurface soil and groundwater conditions.

Its utility extends to:

• Facilitating the evaluation of contaminant movement and behavior below the surface, offering pivotal insights to inform effective remediation strategies.
• Characterizing groundwater flow patterns, hydraulic gradients, and the interconnections between aquifers and confining layers.
• Estimating hydraulic conductivity and transmissivity are fundamental parameters for aquifer testing and modeling.
• Guiding the selection and placement of monitoring wells, ensuring their effectiveness in long-term groundwater monitoring and remediation endeavors.

Geophysical Surveys

Geophysical surveys employ non-invasive techniques to evaluate subsurface conditions without extensive drilling. These methods serve various objectives, including site characterization. Approaches like seismic surveys and ground-penetrating radar yield valuable information, aiding in the detection of subsurface irregularities, soil type variations, and bedrock depth.

Ground Improvement Techniques

Ground improvement techniques are employed in challenging soil conditions to enhance soil properties and increase stability. The purposes include:

• Soil Stabilization: Ground improvement techniques can strengthen the ground in weak or unstable soils. This may involve adding stabilizing agents like cement, lime, or chemicals to improve soil cohesion.
• Compaction: Compaction methods are used to increase soil density and bearing capacity in areas with loose or un-compacted soil.
• Grouting: It fills voids in the soil and strengthens the ground. It’s commonly employed in tunneling and foundation projects.

Sediment Control

Sediment control is the name given to a set of practices and measures intended to stop sediment movement from construction sites into neighboring bodies of water. These solutions hope to prevent ecosystem damage or water quality by capturing and managing sediment-laden runoff. Typical methods for controlling sediment include:

• Sediment Basins
• Silt Fences
• Sediment Ponds
• Erosion Control Blankets
• Check Dams
• Hydroseeding

Inclinometer Surveys

An inclinometer survey involves installing one or more inclinometers along the slope being studied at varying depths, generally inside casing pipes or boreholes. These inclinometers have sensors or probes that can detect changes in tilt or inclination. These probes are placed carefully into the soil or rock mass to track the Earth’s movement.

The survey entails taking precise notes and periodic measurements of the inclinometer values. These measurements are used to monitor changes in slope angles and patterns of deformation over time. Geotechnical experts compare the current readings with the baseline data collected after the initial installation of the inclinometers to determine if the slope is moving or deforming.

Dewatering Systems

Dewatering systems are technical solutions created to regulate groundwater or surface water levels in mines, excavations, building sites, and other places where too much water presents difficulties or dangers for project execution. These systems are used to expedite construction, produce a stable and dry working environment, and stop water-related problems, including floods, soil erosion, and structural damage.

Pavement Designs

Pavement designing involves the planning, analyzing, and engineering of roadways, streets, parking lots, and other paved surfaces. The primary goal of pavement design is to create durable, safe, and cost-effective surfaces capable of supporting the anticipated traffic loads while minimizing maintenance and rehabilitation costs over their design life.

Types of pavements include:

• Flexible Pavements: Materials such as asphalt are used to build these pavements. They are helpful for various traffic loads because they disperse loads across a larger region. Roadways and highways frequently have flexible pavements.
• Rigid Pavements: Concrete is used to build rigid pavements. They can support huge weights and are ideal for areas with considerable traffic. Airport runways and commercial pavements frequently employ rigid pavements.

Conclusion

Geotechnical services are the bedrock of safe, sustainable, and successful construction and engineering projects. They give vital information about a site’s subsurface characteristics, empowering engineers and architects to make prudent decisions throughout the project’s lifespan. Undoubtedly, geotechnical services are crucial for reducing risks, assuring safety, and producing cost-effective and ecologically responsible outcomes in construction and infrastructure development.