Study On The "Double Shell" Mechanical Model And Floor Heave Control Under The Influence Of Deep Soft Rock Roadway Mining

In recent years,the shallow coal seam resource has been exhausted under the mining,most of the roadway has entered the deep mining stage,and it has reached more than 600 m.With the increase of mining depth,surrounding rock shows mechanical mechanism and phenomena and the shallow rock disparate,for soft rock engineering.In the complex stress state,the deep soft rock roadway is characterized by large deformation,serious damage and strong rheology.The bottom drum is the most prominent problem in the deep soft rock roadway,which needs to be solved urgently.In this paper,the deformation and failure mode of deep soft rock roadway floor and its causes are analyzed,and the influencing factors are analyzed.A double open shell continuous model is established,and the formula for calculating the stress distribution and displacement is derived theoretically.In the case of shell mechanics,the optimization is carried out.Through similar material simulation,the roadway deformation and stress distribution,pressure coefficient in the case of 1.5,found along with coal mining,the stress transfer to the deep,especially the floor roadway damage,through the "double shell" support,and achieved good supporting effect.Through numerical simulation,the damage form and stress size of the roadway surrounding rock is obtained when the roadway is in the coal seam floor.The scope of the plastic zone is better to provide technical support for the engineering practice.