Written by David Norbury – Independent Consultant and Chair of the Revision Panel
BS5930 has underpinned ground investigation practice in the UK and abroad since its original publication in 1981. The original version broke new ground by standardising for the first time many of the aspects of an investigation and was published at about the same time as international guidance from ISRM and IAEG on similar themes. This standard always had wider coverage by including guidance on selection of drilling methods, and covering field and laboratory tests.
The subsequent 1999 revision was an update to reflect the ongoing evolution of investigation methods. Since then there have been two major amendments 2007 and 2010) to incorporate the requirements of EN standards related to Eurocodes, specifically the standards associated with EN1997-2, in sampling, testing and soil and rock description. BSI rules do not permit additional amendments, and the decision was taken to undertake a full revision not only to include additional requirements relating to the Eurocodes but also to ensure that current best practice was incorporated throughout the document.
BS 5930:2015 presents an update on the requirements for the investigation of sites in order to assess their suitability for construction and to identify the characteristics of a site that affect the design and construction of the project. The Standard emphasises the importance of the evolving ground model and that ground investigation is not necessarily a linear process. It also considers related issues including the environment and the security of adjacent land and property.
According to the drafting panel, BS 5930 should be used on all investigations to help ensure:
- geotechnical design and ground investigations are achieving the best results;
- UK practitioners are carrying out their work in ground investigation and geotechnical design in accordance with the latest EN and ISO standards;
- UK practitioners can export their skills to other countries where the same international standards are in use;
- the most appropriate equipment is deployed to carry out ground investigation from selection of exploratory techniques, to methods of sampling, testing and measurement;
- complete, accurate and informative description of the soils and rocks encountered; and
- complete reporting of the investigation for use by others in the design chain whether by paper, pdf and digital data transfer formats.
Apart from changing the title from ‘site’ to ‘ground’ investigations, readers might not see much change in the content. However, a lot of effort has been input to update best and current practice, accommodate EN ISO standards and to cut repetition. Not least, the structure of the content has been significantly revised and the Section headings of the revised standard are listed below. Several of these sections have been raised from clause to section level, as denoted by an asterisk below, to better reflect their importance to the investigation process.
- Preliminary considerations
- Desk studies and field reconnaissance**
- Planning ground investigations
- Field work
- Geophysical field investigations**
- Description of soils and rocks
- Field tests
- Field instrumentation**
- Laboratory tests on samples
- Reports and interpretation
- Review during and after construction
The schedule of Annexes supporting the main text is as follows:
- National safety legislation**
- General information required for desk study
- Sources of information
- Notes on field reconnaissance**
- Detailed information for design and construction
- Ground Investigation in ground affected by voids *
- Photographic records**
- Integrated investigations**
The revision process started in late 2011 and was completed in late 2014 when the draft for public comment was issued. The pubic certainly commented with over 1000 comments being received – the largest number ever seen by BSI. A period of intense work in early 2015 saw these comments reviewed and incorporated ready for publication in July 2015. The four year period to revise such a large standard is testament to a lot of hard work by the members of the Panel listed here for the record:
- David Norbury representing the Geological Society of London
- David Entwisle representing AGS
- Dick Gosling representing British Drilling Association
- John Powell present as Chair of B/526/3
- Andrew Ridley co-opted to writ on instrumentation
- Mike Smith present to guide us on integrated investigations
- Graham Taylor representing British Geotechnical Association
and with significant contributions from George Tuckwell on geophysics and Tom Phillips on safety, and not forgetting our patient editor Mary Groom.
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