- Title
- Compression-induced saturation in coal mine spoil piles
- Creator
- Fityus, S.; Robertson, H.; Simmons, J.
- Relation
- 6th International Conference on Unsaturated Soils (UNSAT 2014). Unsaturated Soils: Research & Applications: Proceedings of the 6th International Conference on Unsaturated Soils, Volume 2 (Sydney 2-4 July, 2014) p. 1515-1520
- Publisher Link
- http://dx.doi.org/10.1201/b17034-221
- Publisher
- Taylor & Francis
- Resource Type
- conference paper
- Date
- 2014
- Description
- Coal mining produces large quantities of waste rock (spoil) of generally sedimentary origin. Current practice involves stacking this spoil in piles up to 150 m high. Plans for future mining are considering spoil piles up to 400 m high. Under the corresponding burial stresses, the spoil materials undergo substantial compressions, leading to decreases in void ratio and increases in their degree of saturation (Sr) at constant water content. In this study, a typical spoil derived from Permian-aged sandstones and mudrocks, is subjected to stresses up to 20 MPa, with the corresponding changes in degree of saturation and suction measured. The results show that loose spoil with a water content of around 12% (Sr=25%) will collapse to become saturated under a stress of 7 MPa. In contrast, loose spoil with a higher water content of around 16% will collapse to become saturated under a stress of only 1.5 MPa. From these results, a phenomenon is identified whereby spoil in the seepage and capillary zones at the base of very high spoil piles can collapse to a state of saturation. A discussion is provided on the consequences of this for the matric suction and unsaturated shear strength of these spoil materials, which constitute the foundation layer of the pile.
- Subject
- coal mining; spoil piles; waste dumps
- Identifier
- http://hdl.handle.net/1959.13/1065535
- Identifier
- uon:17865
- Identifier
- ISBN:9781138026902
- Language
- eng
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