Plant & Equipment – Dando 2500
The Dando 2500 cable percussion rig is ideally suited for geotechnical and environmental site investigation drilling up to a depth of approx. 60m depending on the geology. Boreholes are advanced using temporary steel casing from 150mm to 450mm in diameter with the associated drilling tools. This drilling technique is capable of obtaining good quality soil samples for laboratory testing, it facilitates accurate determination of strata depths and enables a range of in-situ testing and sampling including Standard Penetration Tests (SPTs), Cone Penetration Tests (CPTs), thin and thick walled undisturbed sampling (UTs, U100s), piston samples etc.
This rig has been designed to confirm to current Health and Safety standards. Specific features include operationally safe Hatz soundproof engine, remote control rig erection system and winch guarding.
The rig is also suited for the precise installation of groundwater/ground gas monitoring wells, remediation wells and geotechnical/environmental instrumentation.
On this particular project our crew were tasked with drilling to 40m below ground level with in-situ geotechnical testing at a site in central London where space was at a premium. Our client was carrying out a fast turnaround site investigation in order to obtain geotechnical data to enable the design of foundation piles.
Drilling was to be carried out through a basement slab with access limited to a steep ramp. Although the Land Rover was able to access the basement via this ramp, it would not have been possible to tow the rig via this route to the proposed drilling location. Mechanical assistance in the form of a tracked crane was therefore used to lift the rig into position to enable the drilling to proceed.
Completion of a borehole to 40m within the estimated timeframe of 3 days, using 250mm, 200mm & 150mm casing and tooling. Our engineers worked efficiently and safely within an operational construction site. Other contractors engaged at the site were able to continue their operations during the drilling process minimising delays to the overall programme.