FK Lowry Piling recently completed piling works at Cardiff EfW (Energy For Waste) Project for parent company Lagan Specialist Contracting Group. The project comprised of a central 16x48m wide waste bunker 14m deep, with associated surrounding utility buildings consisting of a Boiler and Tipping Halls, Technical and Electrical workshops and administrative offices.
The piling works consisted of 170 no 1200mm dia Rotary Bored and CFA piles up to 25m deep forming secant retaining wall for the waste bunker.
The secant wall was constructed using hard/firm alternative piles at 1700mm centres forming a water tight bunker with reinforced concrete liner wall. To ensure interlock of piles at depth and mitigate water ingress, tight piling tolerances were adhered to. Hard piles were reinforced with 4.5 tonne 25m long prefabricated reinforcement cages inserted with attending handling crane. Concreting was completed by means of tremmie system. The bunker was constructed using 1no high torque CFA piling rig and 2no. rotary bored piling rigs.
The varying utility buildings consisted of approximately 1700 no CFA bearing piles ranging in diameter from 450mm to 750mm, to depths of 23m. With up to 3no CFA rigs utilised throughout, daily concrete consumption was approximately 200m3 with the same volume of spoil generated and removed by Lagan Construction Group. Collectively, both teams co-ordinated the large volume of plant and deliveries.
Pile design and construction was verified by 2no preliminary pile tests, a working dynamic test regime, and 100% integrity testing.
To maintain programme and handover of areas a quick turnaround on pile design and pile reinforcement was required throughout the on-going design changes and release of information.