Mine rock cable made of high-strength and low-relaxation preload steel strand combined with resin adhesive can provide strong pre-stress to strengthen surrounding rock of roadway and fractured coal seam in roof.However,in the condition of roof flooding,the rock cable in free section is more prone to fracture failure due to material corrosion than that in anchorage section.Through theoretical analysis,the fracture mechanism caused by crack propagation under load in corroded free section of rock cable was clarified.Bu laboratory tests and numerical simulation,the corrosion fracture characteristics of rock cable under water leaching environment in high salinity mine were explored,and the correlation of cable elongation and ultimate load in free section with pit depth and surface corrosion rate was also investigated.The results show that stress concentration occurs at the tip of the pit when the cable is under load due to environmental factors,which results in brittle fracture caused by crack propagation.The elongation of the rock cable in free section is negatively correlated with the pit depth.The main factor affecting the reduction of the ultimate load of rock cables is corrosion rate,showing a negative correlation.When the surface pit depth is less than 0.5 mm,the bearing capacity of the 19-strand structural rock cable is better than that of the 7-strand structural rock cable with the same nominal diameter.When the pit depth is greater than 0.5 mm,the bearing capacity of the 7-strand structural rock cable is reverse.
mine rock cablewater corrosionpit depthcorrosion rateultimate load
维普
万方数据
