Geotech 101: What is Geotechnical Engineering?

Most large construction projects start small.

Before the tip of a finished telecom tower can scrape the sky, the soil underneath it has to be sampled. And before a retaining wall can hold the landscape in place, engineers and general contractors have to gain a better understanding of that landscape.

The point? Rock, soil, and other subsurface materials factor into most construction projects. That’s where geotechnical engineering comes in.

In this post, we provide a crash course in geotechnical engineering. What is it? And when should you consult with a geotech engineer? We answer these questions over the course of this article.

What is geotechnical engineering?

Geotechnical engineering refers to the civil engineering discipline that focuses on the characteristics of rock, soil, and other subsurface materials at a given site. Geotechnical engineers investigate earth materials and apply the principles of rock and soil mechanics to generate recommendations for construction plans and solve engineering problems. Geotechnical investigations may precede the construction of a variety of soil- or rock-supported structures, including embankments, landfills, levees, retaining structures, roads, slopes, tunnels, and more.

Geotechnical engineers often collaborate with geologists, technicians, and other area experts to execute drilling plans and sample, test, and analyze subsurface materials before providing construction recommendations. The result? Accurate evaluations of bedrock, groundwater, and soil conditions; detailed foundation design recommendations; and exhaustive documentation of all findings and materials.

Why geotechnical subsurface investigations matter

When it comes to construction projects, what you don’t know can hurt you—or at least your project schedule. Subsurface investigations give designers the information they need to engineer solutions to problems presented by groundwater, rock, and soil conditions. Addressing these issues in advance helps avoid delays, saving general contractors time and money during the construction phase. That’s why subsurface investigations are foundational assessments for many engineering projects. Another plus: geotech investigations can be completed year-round, even in below-freezing conditions.

Geotechnical subsurface investigations accomplish a variety of objectives. However, these investigations vary depending on the location and characteristics of the site in question. In general, subsurface investigations:

• Analyze the color, texture, and moisture of soil, as well as the type, color, and characteristics of any rock.
• Assess the depth, thickness, and characteristics of soil and rock strata.
• Detail the presence and depth of various subsurface materials, including groundwater, soil, and rock.
• Determine bearable capacity and other relevant engineering characteristics.
• Identify problems with the stability of soil or rock.
• Investigate water features and depths.
• Provide long-term maintenance considerations for the site.
• Use field and laboratory tests to assess soil and rock parameters.

Types of subsurface investigations

Geotechnical engineering teams conduct many types of subsurface investigations. These include but are not limited to:

• Earth drilling and sampling
• Earth retaining system evaluations
• Geotechnical site assessments
• In-situ testing
• Laboratory tests
• Rock coring
• Site stabilization and ground modification programs
• Soil and rock slope stability studies
• Soil sampling

Geotechnical engineering services

Ramaker routinely conducts subsurface investigations and provides geotechnical engineering services for commercial, industrial, residential, and telecommunications construction projects. Our environmental due diligence team works closely with site designers to develop testing plans and interpret data.

Ramaker’s engineers have the technical expertise to accurately characterize soil, groundwater, and bedrock conditions on site. The firm also provides foundation design recommendations and documentation of all findings and conclusions.

Need a geotechnical engineering partner? Start a conversation with Ramaker today.