9/05/05 Consolidate secures shale mine workings for housing project

Oil shale spoil tips or 'bings' are a feature of the West Lothian skyline, particularly around the towns of Livingston, Broxburn and Bathgate where they serve as a reminder of the once thriving 19th Century industry that extracted oil from the shale to produce paraffin for lighting and cooking.

The main driving force behind this shale oil industry was chemical engineer James Young, more widely remembered as 'Paraffin Young' and who is often credited as being the father of the oil and petrochemical industry.

The unseen part of this legacy are the unstable remnants of the old shale mines which need to be consolidated if the commercial development of these 'brownfield' sites for industrial, retail or house building projects is to proceed.

Given the soaring land and property prices in nearby Edinburgh and the consequent expansion of the commuter belt into West Lothian, the reclamation of these sites is commercially important.

This is why Persimmon Homes called in ground engineering specialist Consolidate to secure old mine workings for a major house building project at Uphall.

Three exploited shale seams - the Broxburn Shale, the Grey Shale and the Curly Shale - underlay the six acre site at depths between 20 and 35 metres.

In a contract worth up to £420,000, and working in tandem with Consulting Engineers DR Murray & Associates and the developer's roads and services infrastructure contractor, engineers from Consolidate laid out a carefully planned ground consolidation grid system to enable the drilling of boreholes.

Four drill rigs sank a total of 1,975 boreholes, with each hole then being pressure injected with a pulverised fuel ash/cement grout mixture to ensure complete infilling of the mine workings.

Despite having to overcome the complexity of multiple seam treatments and the difficult drilling conditions presented by the deep, soft, shaley strata, the project is proceeding on schedule, with completion expected by the end of May 2005.

Consolidate director Beaton Sutherland, said: "The programming for this multiple seam treatment project was a complicated process but everyone seems pleased with the way it has progressed. We're delighted to have continued our association with Persimmon Homes, particularly this close to our own base. The central belt of Scotland has numerous old coal and shale mine workings, and the reclamation of these brownfield sites by ground consolidation plays an important role in allowing the development of the economies of these areas."