Driven piling in its various forms is without doubt the oldest method of piling dating even in this country back to the Romans, who piled settlements such as York using timber piles driven into the ground with a heavy weight manually raised and dropped by teams of slaves. Modern purpose built driven piling equipment has a mast usually with an efficient hydraulic hammer for top driving a steel tube or a pre-cast concrete section in to the ground.

A J Hurst (Foundation Engineering) Ltd
Unit 9G2, Carcroft Enterprise Park
Station Road, Carcroft
Near Doncaster DN6 8DD

TEL: +44 (0)1302 339 300
FAX: +44 (0)1302 339 600
EMAIL: info@ajhpiling.co.uk

The resistance of the ground opposing the drive of the hammer reflects the capacity of the pile so that by measuring the depth driven by a number of blows gives a measurable indication or “set” to help predict the pile load. The majority of piles driven in the UK are installed with purpose built rigs using hydraulic hammers for the most part manufactured in Scandanavia.

Some piles are formed using a permanent steel tubes driven with a simple drop weight that goes inside that tube and hits the crimped base with an aggregate cushion, this method is more particularly used for smaller lighter loaded piles.

CASE STUDIES

This building in Barrow in Furness is a new Multi Skills Centre at Furness College it was completed in Jan 2007 less than a year after pre- cast piling was installed by AJH Piling.

A CFA pile solution was proposed by our competitors but the site had previously been used as a tip for the nearby steelworks and there was a preponderance of hot poured slag over the area to be piled which when discovered ruled out almost all pile types causing an almost insurmountable obstruction problem. After the usual arguments about who would be responsible for the costs unexpected and unforeseen circumstance. AJH piling contacted the Engineer and agreed to look at removing the Slag in the upper 5m of fill replacing it with selected graded material before driving pre-cast piles. AJH’s price even with the extra work was within budget and piling commenced after only a three week delay and this was largely due to the change of system and the delay of appointing AJH piling.

OTHER CASE STUDIES

The upgrading of an existing quayside in Middlesborough on the river Tees necessitated the installation of driven pre-cast piles through the timber decking of the nineteenth century forerunner. The old timber deck is built off driven oakheart piles that had previously carried a derrick crane rated at 75 tonnes and although the old piles looked in good condition other piling contractors were unwilling to drive their equipment onto this decking. AJH became involved to solve the problem and using a local consultant tried to evaluate the deck’s capacity. It was decided that this would be very difficult, so AJH piling then decided to undertake the work using a power pack onshore and with hydraulic hammer suspended from a high capacity crane on shore to drive the piles. Piles were driven to a set at depths between 16 and 18 m and although this was shorter than expected from previous work on the site. Six dynamic tests indicated that the capacity was achieved with an adequate factor of safety.