- Title
- Effect of constitutive behaviour of strata on the prediction of subsidence above single-seam and multi-seam supercritical longwall panels
- Creator
- Suchowerska, A. M.; Carter, J. P.; Hambleton, J. P.; Merifield, R. S.
- Relation
- 9th Triennial Conference on Mine Subsidence, 2014. Proceedings of the 9th Triennial Conference on Mine Subsidence (Pokolbin, N.S.W. 11-13 May, 2014) p. 149-168
- Relation
- https://www.regodirect.com.au/minesubsidence2014/home/
- Publisher
- Mine Subsidence Technological Society
- Resource Type
- conference paper
- Date
- 2014
- Description
- Numerical methods have the potential to assist in prediction of subsidence, particularly in new mining environments such as multi-seam mining. However, numerical methods have often been criticised for the predictions of subsidence above single-seam longwalls not matching field measurements well. To achieve a realistic prediction, a sound understanding of the mechanical laws governing the deformation of the subsurface strata is required. Within the framework of the finite element method (FEM), this study compares predicted subsidence profiles, as well as stress distributions in the sub-surface strata, for a selection of the different constitutive laws currently used by practising engineers to represent coal measure strata. Further, a strain-stiffening caved goaf material is introduced into the simulations to allow the vertical stresses along the longwall floor to return to the original overburden load. Both single seam and multi-seam longwall panels are considered. A key finding is that the best agreement between predictions and field observations of subsidence is when the coal measure strata are represented as an elastic material with closely spaced frictionless horizontal interfaces, representing bedding planes. With this model the vertical stress also returns to the overburden stress in the caved goaf material within the first seam, prior to extraction of the second seam. The results show that more sophisticated and numerically taxing constitutive laws do not necessarily lead to more accurate predictions of subsidence when compared to field measurements. The advantages and limitations of using each particular constitutive law considered in the study are presented.
- Subject
- constitutive behaviour; strata; subsidence; single-seam mining; multi-seam mining; supercritical longwall panels; finite element method (FEM)
- Identifier
- http://hdl.handle.net/1959.13/1302370
- Identifier
- uon:20466
- Identifier
- ISBN:9780958577960
- Language
- eng
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