Case Study: Teesport Riverside Ro-Ro
Client: Tees & Hartlepool Port Authority
Main Contractor: BAM Nuttall Ltd
Location: Tyne & Wear
The construction of new port facilities in Teesport by BAM Nuttall Limited included the installation of mooring dolphins founded on driven tubular steel piles. In total 60 piles were installed using a barge mounted crane and jack up platform, with diameters ranging from 660mm to 810mm.
Ground conditions proved variable across the site with rock strengths of 15 to 90N/mm2 being recorded. Where hard rock was encountered, the piles could not be driven to the required depth using the pile hammer alone. BAM Ritchies were commissioned by BAM Nuttall to developed and implement a pile top drilling solution to provide rock sockets for each pile.
The drilling work was carried out utilising a modified Atlas Copco A65 hydraulic drilling mast, complete with hydraulic gripper can and working platform. The drill string comprised a Numa 120 down-the-hole hammer [DTH], 200mm diameter drill rods fitted with centralisers and shock absorbers as required. The DTH hammer was powered by two 750cfm compressors operating at 13bar. Drilling diameters were 475mm and 558mm. A total of 30 pile rock sockets were drilled.
The following lists the typical sequence of operations during drilling works:
- Drive pile to initial set
- Brace pile to pile group or piling gates
- Mount pile-top rig onto pile
- Insert drill string into pile
- Drill rock socket through toe of pile and into underlying rock
- Remove drill string and pile-top rig
- Recommence pile driving into [predrilled] rock socket