Stability Analysis Of Reinforcement Of Steeply Inclined

After mining steeply inclined ore body in HBL iron mine,anchor cable reinforcement for roof slab can improve operation safety.As the roof slab of mine is an intrusive ore body with steep dip,its stress condition will be affected by steep dip of ore body and joint bedding.At present,the anchor cable reinforcement of this mine’s steep dip room lacks theoretical support and experimental basis,as well as basic research such as field monitoring data and cable relaxation detection,so it is difficult to guarantee the effect of anchor cable reinforcement,which leads to certain blindness and engineering risks in design,construction and mining.Therefore,through theoretical calculation,field monitoring and numerical simulation,this thesisr studies the instability form of roof slab in steeply inclined mine,providing theoretical basis for anchor cable design.The influence of cable reinforcement mechanism and cable reinforcement parameters on the stability of steeply inclined room is explored,and the cable reinforcement parameters of steeply inclined room are optimized through theoretical analysis and numerical simulation analysis.Based on the field measurement,the stress law of anchor cable is studied,and the basis of construction and tension compensation of anchor cable is given.The thesis mainly completed the following four aspects of research:1.Experimental study on rock mechanical parameters of ore bodyThrough the static characteristic experiment of ore body rock(uniaxial compressive test,splitting test),the static property of rock is obtained,which provides reliable rock mass mechanics index for reinforcement design.Meanwhile,the relationship between the static property of rock and the bedding Angle of rock is obtained by analyzing the experimental results.2.Research on anchor cable reinforcement mechanism of steeply inclined roomBased on the pressure arch theory,the caving of roof slab in 34119N1 mine is calculated theoretically,and the instability characteristics of steep-inclined mine room are studied.It is concluded that the caving arch height is 2.84 m,the maximum stress on roof is 2.44 MPa,and the roof slab is relatively stable.Firstly,the thickness of loose ring of steeply inclined mine is deduced by elastoplastic mechanics,and the thickness of loose ring of roof slab in steeply inclined mine is calculated by equivalent circle method.Based on the theory of loose ring support,the anchor cable support scheme of roof slab in steeply inclined mine is designed.The loose ring of the mine room was measured by digital drilling camera method,and the expanded image of the hole wall was obtained.The thickness of the loose ring of this section was found by statistical analysis of the middle shape and gap width of the hole,and the safety range was initially determined to be about 8.0m.3.Parameter optimization of roof slab anchor cable reinforcement in steeply sloping mineUsing finite element analysis software,taking the mine 3119N2 as an example,a three-dimensional model is established to simulate the stress release process of steeply-inclined mine excavation during the construction stage,to make up for the simplification of theoretical settlement,and to combine the theory with the failure law and instability form of the surrounding rock of steeply-inclined mine.A variety of working conditions were established with two-dimensional model,and the influence rule of main design parameters of anchor cable on the stability of mine room was analyzed by numerical simulation,and the mechanism of anchor cable reinforcement was revealed.Combined with theoretical design,the design scheme of anchor cable was given,and the optimization scheme of anchor cable reinforcement parameters was proposed.4.Study on the law of cable relaxationThe long-term monitoring of the force of the anchor cable and the numerical simulation of the influence of the blasting disturbance can study the tensile loss law of the anchor cable after installation,so as to provide a basis for the theoretical design and the tension compensation of the anchor cable.