Research On The Deformation And Failure Mechanism Of Roadway Considering The Characteristic Of Damage And Strain Softening

With the easy exploited mineral resources reducing,coal mining under the worsegeological environment demand for higher request to the stability maintenance ofroadway.Under the condition of high in-situ stress and complicated geologicalenvironment,rock may exist the properties of low strength,easy broken and post-peakcohesive reducing.The feature of Pre-peak damage and post-peak softening should beconsidered for roadway stability maintenance and supporting plan options.On thebackground of roadway in fault of Yuandian103mining area,using the methods oftheoretical analysis and numerical simulation by establishing the rock mechanicalmodel with FLAC3Dto study the mechanism of deformation and support ofroadway.The main results are as follows:(1)The damage threshold was deduced according to the theory of fracturemechanism and damage variable describing rock elastic modulus damageing wasimproved.Thus the mechanics model describing the pre-peak macroscopic damagecharacteristics was established.(2)On the question of circular roadway the analytical solutions of stress anddsplacement of elastic zone and plastic zone were deduced using the simplifiedcohesion strain softening model.Then the effects of roadway deformation and failurecaused by post-peak stain softening was analyzed.(3)Using FLAC3Dsoftware to develop models of pre-peak damage andpost-peak softening and the tension and compression numerical experiment ofstandard cylindrical specimen was carried out to confirming reasonable of the model.(4)Roadway deformation and failure characteristics was analyzed consideringpre-peak damage and different damage threshold and different damage variable.Theeffects of damage and deformation control by different supporting scheme wereresearched.(5) Roadway failure characteristics in defferent grouting time was researchedconsidering post-peak strain softening.The importance of grouting time to control thefinal deformation of roadway was verified.Then the optimal grouting time waspursued.