It might not be the kind of thing he’d mention at a dinner party, but Dr Melvin England is a world authority on pile testing. And, after 13 years with Cementation, he recently jumped ship to establish a European base for Loadtest, a US company that specialises in “bi-directional” or “O-Cell” static load testing, in the UK.
Dr England joined Cementation in 1990 from the defence industry where he had developed guidance systems for missiles. Cementation’s board of directors, then led by Dr David Greenwood, brought him in initially “as a pair of fresh eyes with a fundamental physics background” to develop the company’s role in the emerging market of pile integrity testing and instrumentation.
But “I quickly came to the view that there was a tendency within the industry to overstate the value of some of the tests,” he explains.
He was also soon convinced that the only reliable way to determine a pile’s settlement behaviour under working conditions is by long-term static load testing, and this belief has provided the focus for his work ever since.
The O-Cell is an exciting development, Dr England insists, because it is, fundamentally, a static load test method. The clever bit about the O-Cell, he explains, is that instead of requiring a reaction system at the ground surface against which the pile is loaded, it uses the test pile’s capacity to provide the resistance to the reaction load.
This is achieved by casting a sacrificial jack – the actual O-Cell – into the pile. This separates the pile into two elements, one of which is tested against the other.