“Myth” is not a term that one would normally associate with geotechnical engineering, a discipline only established in the twentieth century.
However, a working group chaired by Cambridge’s professor of civil engineering Kenichi Soga has so far identified 31 potential “myths” - such as the idea that soils are either fully drained, or fully undrained - and is inviting input from the geotechnical community to prove or disprove their veracity.
Some of the myths owe their origin to work of pioneers in the subject who were looking for workable approximations and models to enable them to develop design methods, which would serve as a means of proving the value of the discipline. Others may have come about as short cuts and imperfect teaching.
The study, called Myths and Misconceptions in Ground Engineering, was introduced at the British Geotechnical Association (BGA) Conference at ICE in June.
Earth structures developments
Significant developments have of course taken place in the design of earth structures through empirical means, and observations of failures. This year is the bicentenary of the birth of one engineer who exemplifies this process.
John Frederick Bateman was the most prolific designer of earth embankment dams for water supply in Victorian Britain.
Bateman was born near Halifax, but moved to Manchester as a child. It was there that he received his training as an engineer and surveyor and set up business.
The linked reservoirs of the Longdendale water supply scheme provided Bateman with the experience to develop as a designer of embankment dams. In an area prone to landslides and with difficult geology associated with heavily jointed rock, Bateman learned first hand the problems associated with inadequate site investigation, landslips, cracked outlet pipes and hydraulic fracture. Informed by his own difficulties, and the infamous failures at Bilberry and Dale Dyke, he began to use layers of selected cohesive material either side of the puddle clay core.
At the second Woodhead Dam in Longdendale, he introduced a concrete cut off, realising that puddle clay was unlikely to resist the water pressure in open joined rock 50m below crest level.
Bateman’s work was not all about large dams. The Loch Katrine scheme for Glasgow’s water supply only required an initial raising of water level of 1,200m. The aqueduct, with 13 miles of tunnel and 23 miles of pipelines, was the main civil engineering feature.
Bateman’s practice was continued by his long-term assistant and partner George Henry Hill. GH Hill & Sons continued as a Manchester-based consultancy specialising in water supply well into the 1980s.