The A14 traffic management scheme runs for 130 miles west to east from the interchange with the M1 Junction 19 at Catthorpe in Leicestershire to the A14 Junction 62 at Felixstowe in Suffolk. The project involved the installation of an ‘intelligent transport system’ including incident detection and automatic queue protection at targeted intersections, strategic diversionary information at key junctions and extensive CCTV coverage, to improve incident response rates.
Provisional studies undertaken by Atkins determined the location of one hundred and thirteen new gantries/cantilever mounted variable message signs and CCTV masts. For each new structure an exploratory borehole was required in order to obtain provide sufficient geotechnical, geoenvironmental, geological and hydrological information to allow the design and construction of the scheme to progress.
The ground investigation was carried out by RSA Geotechnics on behalf of the client, the Highways Agency, under the directions of the principal contractor, Birse Civils. The scope of work comprised the drilling of one hundred and fifty exploratory boreholes. The fieldwork was carried out during a series of night time lane closures undertaken between April 2009 and July 2010.
Depending upon the ground conditions encountered the exploratory boreholes were formed using either conventional light-cable percussion methods or rotary boring. Some of the proposed gantries and CCTV masts were to be located within the cutting or embankment slopes and in order to ensure that the exploratory boreholes were sited close to the proposed structures it was necessary to either construct a temporary scaffold drilling platform or use a specialist slope climbing drilling rig.