Understanding Phase 1 of the Ground Investigation Process: Desktop Studies

by | Apr 5, 2023

Prior to any construction project’s commencement, conducting a preliminary ground investigation is an integral component of due diligence. After all, unforeseen ground conditions often lead to extensive delays and additional costs for developers and occupants alike. Across the geotechnical industry, the process of conducting these investigations consists of four key phases. These include: ‘Desktop Studies’ (Phase 1), ‘Site Investigations’ (Phase 2), ‘Remediation Designs’ (Phase 3), and ‘Testing and Validation’ (Phase 4). Each phase is equally important as the next, and today, we wanted to focus on Phase 1 – desktop studies.

What are Desk Studies?

Desk studies involve collecting information and documents with the intention of identifying and assessing potential hazards to development. These studies are entirely investigative, and as such, the consultant will draw from many resources when coming to a conclusion. This could include accessing architectural development records, site maps, as well as previous site uses such as mining and hydrogeology. Fundamentally, they will look to paint a comprehensive picture of the site, and any potential risks that may exist. In many cases, however, a site walkover will also be deemed necessary to confirm these risks.

Ground Investigation Walkover Surveys

As most Phase 1 ground investigation reports are commissioned under planning requirements, walkover surveys are often compulsory. In fact, the National Planning Policy Framework (NPPF) deem them to be the minimum requirement, even when not explicitly stated. Walkover surveys look to verify site characteristics or highlight any other potential issues likely to impact development. Whilst each site differs from the next, site walkovers look to record information, such as:

  • Presence of odours and visible site brownfield land
  • Ecology
  • Local water features
  • Current use of the site, if applicable
  • Surrounding land use and emissions
  • Presence of flora and fauna
  • Access and security
  • Surface ground features

For more information about walkover surveys, click here!

Objectives of a Phase 1 Desk Study

When conducting Phase 1 of a ground investigation study, your objectives typically focus on determining whether further action is necessary. This could, for example, involve assessing the presence of contaminants and considering whether intrusive geotechnical investigation is required. Also, one of the overarching objectives of desk studies is the preparation of a Conceptual Site Model (CSM). These are representations of various processes which determine how contaminants may move throughout the site environment.

Reviews and recommendations

Phase 1 isn’t solely identifying areas of risk, but also providing extensive recommendations on how to address them. Each recommendation is broken down into different tiers, dependent on the specifics of your planning requirements. For instance, this would determine whether intrusive investigations are required to validate findings, or whether visual inspections alone are sufficient.

Contact Borehole Solutions

Whilst preliminary ground investigation studies may feel like a tedious process, they are still imperative to the development process. So, if you’d like to find out more about desk studies or any other of our geotechnical services, get in touch! Call us today on 01733 200501 or send an email to info@boreholesolutions.com to chat with the friendly team at Borehole Solutions.