Synergistic bearing mechanism of asymmetric roof-pillar structure body in goaf of inclined orebody
To solve the deformation and failure instability of the support structure body,which may be triggered by the large dip roof and asymmetric goaf after mining of the inclined orebody.The asymmetric roof-pillar support structure body of a limestone mine was taken as the research object,a structure mechanical model was established,the flexural deformation value of roof and safety factor of pillar were solved,the deformation characteristics of roof and instability failure mode of pillar in different angles and span ratios were analyzed,and the collaborative bearing mechanism was studied.The results show that the deformation of roof and the instability failure mode of pillar are doubly influenced by the dip angle θ and the span ratio λ of the goaf,and the deformation value of roof shows a double growth rate with the increase of θ,and its relationship with λ is related to θ.The influence of θ on the instability failure mode of pillar decreases with the increase of λ.When 0°＜θ≤30°,the pillar is mainly small eccentric compression failure;When θ=0° and 30°＜θ≤60°,the failure mode of pillar from large eccentric compressive failure to small eccentric compressive failure with the increase of λ.The ability of the roof to maintain the stability of the goaf gradually decreases with the increase of θ.The optimal λ of the pillar to maintain the stability of the goaf gradually decreases with the increase of θ.The effect of the pillar to restrain the deformation of roof decreases with the increase of λ.The numerical simulation results and engineering examples verify the reliability of the theoretical calculation results,and provide some theoretical supported for the safe mining of underground open stope method.
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