Plenmeller is a remote upland opencast site in Northumberland designed to produce just over 2 million tonnes of coal during eight years of production. The complex ground conditions comprise thick peat and glacial deposits, overlying much faulted and steeply dipping Coal Measures strata. Previous under- ground workings, high groundwater levels and associated sub- surface reservoirs of water are also present. In order to mine and export the coal off-site, extensive infrastructure works were necessary including impounding embankments for lagoons, public road diversions, an overland conveyor with a tunnel and major river crossing, coal screening and crushing plant and a rapid loading bunker with associated railway sidings.

A lengthy planning history included a public inquiry and a high court heating before coal production commenced in August 1991. Imposed planning constraints required modifica- tions to the development, additional construction works and restoration measures. The combination of the site location, infrastructure requirements and planning constraints gave rise to the need for a wide range of ancillary civil engineering works; this was one of the most extensive programmes in connection with an opencast project in the UK. These engineering works in turn required a substantial geotechnical input. This paper presents a general account of the extensive ground investiga- tions and construction works carried out at Plenmeller, and briefly discusses some geotechnical aspects of the site operations and the construction works.

First Page Preview

First page PDF preview
You do not currently have access to this article.