Geotechnical Investigation for Land Development Projects

All land is buildable. Architects from Venice to Mexico City have proven that time and again for centuries, the question is how much time and money will the project take, and how durable will the result be?

Thanks to modern investigative soil boring methods, we can now understand the subsurface properties of a piece of land in great detail, including the type of soil, its stability, how the soil properties vary at different locations and at different depths, and where groundwater is present at the site. This informs us whether the land is currently suitable for building, what type of construction the land can support, and what changes and soil improvements would need to be made if the land had to be used for a specific purpose.

The information gained from a geotechnical investigation is not just useful to a construction project, it’s critical. The land intended for a project carries with it more unknown factors than the entire rest of the construction process, and compensating for poor-quality or unsuitable land has the potential to increase the overall cost of a project dramatically. Geotechnical investigation is a strong risk-assessment tool and a reliable cost predictor for construction projects of all sizes and types, from residential family homes to commercial buildings or structures to international airports.

How is a geotechnical investigation performed?

To understand the geotechnical properties of a piece of land, Element’s experts perform soil exploration investigations. We collect soil borings using drill rigs mounted on trucks, ATVs, or tracks with hollow stem augers and split spoon samplers that collect long, slender columns of material from various locations on the site. Project sites may need dozens or only a few soil borings, depending on the size and variability of the land. The samples collected allow our geologists and engineers to examine soil profile layers at various depths to determine what they are comprised of, how much capacity they have, and how stable they are.

Based on the information in the samples collected through soil borings, our experts can make reliable recommendations about what size and type of project the land can support, and what site modifications might be necessary to make the land suitable for the intended project.

What is the purpose of a geotechnical investigation?

A geotechnical investigation determines more than just the soil’s bearing capacity. It provides detailed information about the properties of the soil, groundwater, bedrock makeup, and information about any portions of the property that may have unfortunately suffered environmental impact from human activity. All of this data is used when designing site features including foundations, retaining walls, pavement, infiltration/filtration basins, ponds, or any other structures that require support and earth disturbance. A geotechnical investigation details subsurface conditions and helps determine how the soil and groundwater will respond to the proposed changes. Recommended soil corrections and any potential improvements are detailed in geotechnical reports, which are used to aid project cost estimations for earthwork activities and risk management by minimizing cost overruns.

Residential and commercial projects

In most cases, a geotechnical investigation will be required by your local municipality before a new home or commercial project can begin, however, by that point, many would-be home builders or commercial developers have already purchased the land they intend to build on. Wherever possible, prospective land buyers should insist on a geotechnical investigation performed by a qualified engineer prior to a land purchase. The party selling the land is typically not motivated to conduct an investigation unless they are required to because it can reveal problems or issues that may decrease the land’s value. If the buyer intends to build on the land, an investigation is crucial to accurately determine the land’s value and potential costs for land improvements.

Unfortunately, many plots in both residential and commercial areas have geotechnical issues that are invisible without an expert investigation: it’s not uncommon for buyers to find that their newly-purchased property was once a landfill or a swamp or is located on an unstable embankment. Without expert insight, land buyers can be stuck performing large soil corrections to make a lot buildable, or using non-standard deep foundations or earth reinforcement techniques to properly support structures or site features. This can lead to thousands of extra dollars’ worth of expenditure in the process.

Large-scale industrial and municipal projects

The more complex a project is, the more dire the consequences of unforeseen geotechnical problems can become. Projects like airports, railroads, and projects for the oil and gas industry require extensive research and development efforts that rely heavily on the information provided by geotechnical engineers. The insight of a qualified geotechnical engineer not only determines what steps must be taken for the safety and longevity of the project, but can also inform developers and owners on how to reduce cost through well-planned design, appropriate building materials, and land purchasing decisions.

For example, Element has in the past been contracted to perform geotechnical investigations for a large-scale industrial building site that included a railroad extension and rail laydown yard. The proposed route for the railroad track was through an area of wetlands, and the engineers were tasked with determining whether it would be more cost-effective to correct or stabilize the swampland enough to support a railroad track or to buy an adjacent piece of land and divert the track around the swampland altogether. These types of critical determinations must be performed by engineering professionals with extensive and up-to-date practical experience, which makes choosing the right company to partner with crucial to a project’s success.

Choosing a geotechnical engineering partner

The most important factors in getting accurate results from a geotechnical investigation are the skill levels of the engineers, the reliability of their methods, and the clarity of their reports. Meaningful geotechnical investigations rely on accurately interpreting the samples from the site and making well-informed predictions about the site’s suitability for building, which requires a deep understanding of both geotechnical engineering and available building materials and methods. The land has been formed over centuries of time and has often been affected by human activity, so no two sites are ever the same, and only the right quality of expertise can ensure that a project is completed safely, accurately, and in a timely fashion.

Element Materials Technology employs the best-educated and most experienced scientists, technicians, and engineers in multiple industries, allowing us to provide an unparalleled array of geotechnical and construction materials testing services. We can offer testing and consulting for multiple aspects of your project, allowing us to offer comprehensive input and superior recommendations for the desired successful project outcome.

Element laboratories also perform both conventional product testing and failure analysis, giving our engineers a unique perspective on real-world failure cases. They use this knowledge to more accurately identify potential problems before they arise. Element is also at the forefront of testing new and innovative building materials, from new blends of concrete to 3D-printed structural materials. Element experts use their experience and understanding of existing standards to evaluate how new materials should perform under real-world conditions – even if there are no industry standards to test them against yet. To learn more about how Element can support your development project, contact our experts today.