Impact Compaction Process and Its Action Characteristics of Material in Vertical Orepass
The impact-ramming in the process of ore-rock unloading in a vertical orepass affects the fluidity of the ore-rock and the stability of the orepass wall,and is also an important factor causing the blockage of the orepass and the instability of the shaft wall.Aiming at the action mechanism of impact-ramming during ore-rock unloading from the upper part of orepass,discrete element numerical model is used to simulate the process of ore-rock discharge into a vertical orepass,the influence characteristics of impact-ramming on internal force chain structure distribution,the voidage of stored materials and the wall side pressure of storage section are studied.Under the current orepass structure parameters,when the ore storage height is 40 m,it is found that:① The impact compaction process includes five processes:falling,collision,extrusion,rebounding and covering,and the impact force passes through point impact,surface impact and space expansion in turn.② In the process of stress transmis-sion,only the force chains within 4 m below the storage surface will break and recombine,the force chains in other ranges will be strengthened or extended,and the distribution of force chain structure of the whole storage material changes little.③ Impact compaction has a great influence on the viodage within 5 m below the storage surface,and the change rate of storage voidage in other areas is less than 1％.④ In the process of ore unloading,the shaft wall near the storage surface of the chute will bear great impact,resulting in the damage of the shaft wall.Impact compaction will also increase the static lateral pressure of the shaft wall in the middle and low part of the ore storage section of the chute,accelerate the wear of the shaft wall and increase the incidence of overhanging arch.
vertical ore-passstored materials in orepassimpact-rammingvoidageshaft wall stress
万方数据
维普
