Geotechnical engineering applications in opencast coal mining : case studies from Northern England
Opencast coal mining using mechanical excavators has taken place in Northern England for over sixty years. In the early years the excavations for coal were relatively shallow and of limited area, typically less than 20 m deep and 50 ha in plan. Nowadays with the deployment of very large draglines and hydraulic shovels, opencast mines can be over 200 m deep and up to 1,000 ha in area. The investigations, excavations and earthworks failures associated with this activity have provided a unique opportunity to study several geotechnical engineering aspects of the drift and solid geology of Northern England, and how they impact on the mine planning, design and operations processes.