Bearing capacity of rock over mined cavities in Nottingham.

Waltham, AC; Swift, GM

Abstract

A significant geohazard is created in Nottingham, UK, by hundreds of man-made caves cut in the weak sandstone beneath the city centre. Stability of the caves has been assessed by a single full-scale loading test, by numerical modelling with FLAC and by physical modelling in plaster. For typical caves 4 m wide, bearing capacity of the rock roof rises from 2 MPa where it is 1 m thick to 8 MPa where 3 m thick. Stability decreases over wider caves and where the loading pad edge is over the edge of the cave. Numerical modelling of a very wide cave revealed the failure mechanisms and also showed that an internal support wall increased roof bearing capacity by 50%. Local building regulations that require 3–5 m of rock cover over the sandstone caves appear to be conservative. In stronger rocks, including karstic limestone, a guideline that cover thickness exceeds 70% of the cave width appears to be appropriate.

Citation

Waltham, A., & Swift, G. (2004). Bearing capacity of rock over mined cavities in Nottingham. Engineering Geology, 75(1), 15-31. https://doi.org/10.1016/j.enggeo.2004.04.006

• Journal Article Type: Article
• Publication Date: Jun 17, 2004
• Deposit Date: Oct 9, 2007
• Journal: Engineering Geology
• Print ISSN: 0013-7952
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 75
• Issue: 1
• Pages: 15-31
• DOI: https://doi.org/10.1016/j.enggeo.2004.04.006