Improving Traffic Flow on A46 in Warwickshire and West Midlands

Geotechnics Limited undertook a major site investigation (£148,000) for Morrison Construction in relation to improvements to Jct 15 of the M40 to reduce congestion on the A46 and Longbridge roundabout.  This scheme is now complete and traffic on the A46 bypasses Jct 15. 

In pursuance of improving traffic flow on the A46 further improvements are under consideration for the Toll Bar Island, Coventry.

Geotechnics Limited have recently completed an investigation for sign gantries on the A45 and A46 (£60,800).  This work involved drilling boreholes on the verges, which for the A46, required working at night under Traffic Management and lane closures.

Twelve boreholes were required to be drilled using mini tracked rotary rigs, due to space limitations, with dynamic sampling/SPTs in overburden and rotary core drilling in Mercia Mudstone bedrock.  Boreholes were generally completed in a single shift, making maximum use of traffic management, except for a 25m deep hole which took two shifts.  Drill flush was contained using sand bagging around the borehole location and recirculation techniques.

At three locations, boreholes were located behind barriers which precluded drive on access.  In order to access these, the rig was brought to and lifted onto location using a hi-ab lorry.  Dismantling of the barrier was discounted as an option as at least one post would also have had to be removed and these could not be returned to working condition within the permitted night closure times on the A46.

Dynamic Sampling and Rotary Core drilling achieved full recovery permitting full strata descriptions and sample availability for subsequent laboratory testing.