Updates to the UK Specification for Ground Investigation

These were updated and reissued in 2012, the original first two volumes becoming a single document under the title Efficient Site Investigation, while the fourth volume, addressing investigation of potentially contaminated land, was replaced by a publication from the British Drilling Association (BDA).

The 2012 second edition of the Yellow Book was prepared primarily by chief author Dr. Mike Atkinson of Soil Mechanics (Environmental Scientifics Group), the company that has developed into SOCOTEC's GI business, as a joint project between Soil Mechanics and the Association of Geotechnical and Geoenviromental Specialists (AGS).

The Specification provides an essential link between standards and recognised good practice, and the practicalities of specifying ground investigation requirements by designers for pricing by contractors. It is at the heart of nearly all GI contracts carried out in the UK.

Since 2019, the AGS has been working on the third edition, intended to reflect changes in the industry during the last decade. This has been co-authored by Julian Lovell, immediate past chair of the AGS, who also started his career at Soil Mechanics. The revision working party includes SOCOTEC's Mark Toye, who also represents the BDA.

Users of the Yellow Book will find the structure of the revised edition familiar, with changes made where necessary to reflect updates in legislation, guidance and standards, as well as new technology and practices.

• Drilling methods – use of sonic drilling, measurement while drilling (BS EN ISO 22476-15) and core scanning
• Surveys – pre- and post-condition site inspections, UXO surveys, use of drones, and cavity inspections using remote methods
• Underground utility surveys in accordance with PAS 128.

Recognition of more recent practices includes, for example, greater emphasis on the measurement of water quality parameters during purging and sampling. It also provides clarification that post-fieldwork monitoring carried out after submission of the draft report is to be presented as an addendum report.

Of note is the clarification to the types of reporting. Reporting requirements should refer to the Ground Investigation Report (GIR) or Geotechnical Design Report (GDR), or parts thereof, rather than Factual and Interpretative Reports, except when a contract is being undertaken outside of BS EN 1997.

The Specification has been amended to consider more recent approaches to digital reporting, such as PDF digital reports and AGS format digital data. The latter is now commonly used for data interchange during the works rather than as an end of project report. There are also clearer definitions of preliminary, draft and final data.

The draft document was issued for public comment in June 2021. SOCOTEC's Technical team carried out the review and provided much feedback for consideration. Members of SOCOTEC who represent on various AGS Working Groups were also involved in preparing response to the authors.

Publication of the third edition is expected during 2022 and will be welcomed by the industry.

However, it is worth remembering that guidance and standards can only go so far. It is essential that those preparing specifications are sufficiently competent to provide clear requirements and a level of detail to enable contractors to price and execute the works. As with most GI contractors, SOCOTEC is keen to promote early contractor engagement. We are always happy to assist designers at pre-tender stage to ensure that ground investigations are suitably targeted and cost-effective for their projects.