The British Geotechnical Association (BGA) with support from the Federation of Piling Specialists (FPS) hosted a conference on Piling last month. The event was originally due to be held in Durham, however, due to Covid-19 restrictions, the conference was held as an online event which ran over 4 days from 23rd to 26th March 2021.

There had not been a conference related specifically to piling for a number of years, however, recently there have been many technical developments in the field related to offshore and onshore projects namely the development of offshore wind farms and major infrastructure projects.

With the amount of work currently underway, it was felt appropriate to focus on this topic and to bring together the knowledge and experience gained in recent years, including conference papers and a series of authoritative keynote lectures on important aspects of Piling, including case histories to provide a definitive up to date perspective on geotechnical aspects of piling.

One of our principal Engineering Geologists, Luisa Dhimitri, co-authored a research paper with David Illingworth from Pile Designs, titled ‘Review of CPTU testing and pile designs parameters from glacial deposits in Perth’.

The paper identifies a glacial meltwater deposit beneath Perth town centre which provides a suitable bearing stratum for piled foundations, that has been undervalued due to the difficulties in assessing reliable geotechnical parameters. After reviewing 15 grading analysis results, 34 plasticity tests, 11 undrained triaxial tests, 15 Standard Penetration Tests and 45 Cone Penetration Tests it is clear that the material is mainly a laminated SILT with a reasonably consistent profile in depth and lateral extent. Site investigations using CPTU provide a better assessment of the in situ characteristics of the material compared to more conventional techniques. This is demonstrated with regards to pile design parameters. The paper also reviews the results of several pile tests, installed using Continuous Flight Auger (CFA) techniques and back analysis shows a fairly consistent range of derived parameters.

This paper was presented by Luisa and Dave on 25th March, where they had nearly 100 viewers for their talk and were available afterwards to answer questions.