During January 2010, Topdrill Ltd successfully installed 17 groundwater monitoring wells in Stonehaven for Aberdeenshire Council under the supervision of Jacobs Geotechnical Department in Glasgow, in the latest stage of an ongoing site investigation. The site is particularly challenging and hazardous due to being on a steep and unstable gradient and has a long history of slope instability. One of the main challenges faced, was to try and minimise any further disturbance to the slope. With this in mind, Topdrill provided a modular window sample rig, which has the ability to work on steep gradients with a nominal level platform. The rig, being of a modular nature, can be taken apart into hand manageable sections, carried to site and re-assembled. This enabled Topdrill to access positions without the need for a crane to lower equipment onto the already unstable slope, again minimising disturbance and removing the risks associated with heavy plant being tracked or lowered down steep slopes.
An advantage of using the modular rig over hand held equipment, is the ability to case the hole, which became necessary with the variable groundwater conditions beneath the slope. Topdrill successfully provided installations to monitor specific horizons in the mid slope section.
Although not used on this specific project, further advantages of the modular rig over hand held equipment are the ability to undertake SPT tests and undisturbed sampling to aid design.
The project was completed successfully on time and to budget.