Geotechnical investigation for pile design
SafeLane supported a geotechnical consultancy client by drilling boreholes to assess ground conditions in central London ahead of planned piling works.
The continuing investment in development in London means the need for the provision of data to builders and developers about the characteristics of the geology beneath their sites is increasing.
SafeLane not only ensures such sites are safe from the risk of unexploded ordnance contamination, it provides geotechnical services too.
Recently it was appointed by a regular geotechnical consultancy client to drill six boreholes to depths up to 60 meters using two cable percussion drilling rigs. The client wanted to assess ground conditions ahead of planned piling works.
The site already housed six business which had to remain open during the 10-week project.
These businesses ranged from a car hire business to a cocktail bar – and all required the drilling work to be as clean and contained as possible so no business would be lost.
The complex geology of central London required the boreholes to be drilled using a range of equipment and tooling ranging from 300mm to 150mm.
Samples were taken throughout the drilling process to allow laboratory testing along with geotechnical tests.
Tests undertaken included standard penetration tests (SPT), cone penetration tests (CTP) and U100s.
The boreholes were installed with ground water and gas monitoring installations, and with multiple nested installs allowing the different strata to be monitored and tested.
Due to the required depths of some of the boreholes, SafeLane’s crews were putting up to 8 tonnes of casing into the ground to prevent water from entering the boreholes.
Poorly consolidated ground also had to be supported to prevent collapse.
The data delivered was used for pile design and to allow the ground to be monitored during construction.