~Warwickshire County Council~ highways staff are to use ground-penetrating radar to check for hidden surprises in the path of their continuing Leamington Parade improvement scheme.
This comes after works were held up last year when they stumbled on a series of shallow and crumbling cellars.
The decision to conduct a ground radar survey after Easter, in advance of phase two of the £2.2M scheme, follows the discovery that Georgian cellars extending beneath the existing Parade footways lay close to the surface and, in some cases, on the point of collapse.
Weak roofs had to be strengthened with steel plates, and in the worst cases, cellars were filled in. Contractor Mowlem had to resort to hand digging around them to avoid causing further damage.
The new footway along the whole of the Parade will be laid on a 150mm concrete base, to give added strength. Square-edged paving slabs, which proved difficult to lay evenly in phase one, are to be replaced in phase two with chamfered slabs.
Warwickshire’s highways team leader, Steve Young, said internal surveys of cellars would also be carried out where possible, although many of those encountered in phase one had been bricked up and occupiers were unaware they existed.
‘We knew we would come across some cellars, but we didn’t realise just how shallow they would be,’ said Young. ‘Some were directly below the slabs, with services running across the tops of the arches.’
A similar problem with under-street cellars was encountered two years ago by ~Oxfordshire County Council~ during its problematic upgrade of Oxford’s Cornmarket Street (Surveyor, 13 May 2004).
The additional cost of the extra works in Leamington and delay to the contract were still being calculated, added Young. The town centre improvements, which are being accompanied by resurfacing, new traffic signals and a 20mph limit, were due to be completed last October, but after a four-week overrun, the contract was suspended to avoid disrupting Christmas trading.
Phase two, expected to take 12 weeks, will begin on 5 June.