Brazilian disc splitting tests and numerical simulations on coal samples containing bedding planes

Inthispaper,Braziliandiscsplittingtestsoncoalrockspecimenswithbeddingplanesand correspondingsimulationsbycombinedfinite/discretenumericalmethod(FDEM)werecarriedout.The resultsshowthattheangleofbeddingplanehaveasignificantinfluenceonfracturepatternandtensile strengthofcoal.Itisclearthatastheangleofweakplaneincreases,thefracturepatternofmodelscan beclassifiedintofourtypes,includingstretchingfailureperpendiculartoweakbeddingplanes,complicatedsketchingandshearmixedpattern,shearfailurealongthebeddingplanes,andsketchingdamage alongweakbeddingplanes.Asforthedifferenceoftensilestrengthvalues,itisobservedthatwhenthe loadisperpendiculartothebeddingplane,theeffectofbeddingstructureoncalculatingtensilestrength isnegligibleandthetensilestrengthvaluedecreaseswiththeanglerisinguptotheminimumvalueas anglereachesvertical.Inaddition,withrespecttodissipatedenergyofcoalsamples,itisconcludedthat thedissipatedenergygraduallydecreaseswhentheangleofbeddingplanesareincreased,whichhavea relationshipwithvariedfracturepatternsandstrengthvalues.