A MASSIVE scaffolding platform had to be built at the site of a recent cliff failure in Devon before work could start to repair the slope. Site investigation contractor Soil Mechanics had to carry out drilling from the platform because of concerns over further slips occurring when drilling rigs were moved and operated above the failure.
A section of the cliff below Castle Hill, in Seaton, failed in November last year after a period of heavy rainfall. To study the slip - which penetrated the underlying weathered Mercia Mudstone layers - a number of trial pits were excavated behind and on top of the failed section, and rotary bore-holes sunk.
But to ensure that the weakened mat- erial behind the backscar of the slip was not further stres-sed when the skid-mounted Edeco rotary rig was in the correct position to drill the boreholes, the scaffolding platform had to be erected. This was designed to distribute the weight of the machinery and equipment, transferring much of the load on to the promenade at the base of the cliff.
The investigation, carried out for East Devon District Council, was supervised by Posford Duvivier which will use the data obtained from field and laboratory tests to design remedial works that will support the cliff and to prevent further slips.