Research And Application Of The Synergistic Anchorage Technology To The Surrounding Rock In Coal Mine Roadway

With the country's increasing demand for energy,coal mines have gradually entered deep mining.However,the high geostress,high ground temperature,high osmotic pressure and strong mining disturbances faced by deep mining have brought great challenges to the anchorage of deep coal mine roadways.Therefore,it is very important for the safe mining of deep mine to further study the anchorage theory which is suitable for the control of deep surrounding rock.Based on the principle of synergy,this paper takes the control of surrounding rock in deep roadways as the research object,and uses theoretical analysis,similar simulation tests,numerical simulation,engineering practice and other research methods to mainly study the changes of mechanical parameters and stress state of surrounding rock caused by rock bolt anchorage parameters,and to prove the synergetic effect of "1 + 1 > 2" in roadway anchorage engineering.The main research results are as follows:(1)In-depth analysis of the mechanism of rock bolt and cable,introduced the composition and basic characteristics of synergistic anchorage systems,and studied the mechanism of rock bolt-cable synergistic anchorage and the advanced of synergistic anchorage technology.(2)Similar simulation tests show that: each anchorage parameter has the most obvious strengthening effect on the residual strength of the anchor solid,followed by compressive strength,and the weakest strengthening effect on the elastic modulus.The elastic modulus,compressive strength,and residual strength of the anchor solid show a trend of increasing first and then decreasing with the increase of the density of the rock bolt;it increases with the increase of the length of the rock bolt,but the increase amplitude decreases gradually;with the increase of anchorage length,it first increases and then decreases;it increases linearly with the increase of the tray size,and the effect of the steel belt is significantly better than the steel ladder.The strengthening effect of each anchorage parameter on the internal friction angle of anchorage solid is better than that of cohesion.The effects of rock bolt density,rock bolt length,anchorage length and composite components on cohesion and internal friction angle of anchorage solid are similar to those of uniaxial compression test.(3)Numerical simulation tests show that: as the distance between rock bolts decreases,the area of stress superposition within the anchor solid continues to expand,and the stress values and synergistic increment at the monitoring points continue toincrease,but the increase amplitude shows a trend of increasing first and then decreasing.There is a synergistic length between the rock bolt and the anchor solid.When the length of the rock bolt is less than this length,the internal compressive stress area of the anchor solid is small and cannot effectively anchor the surrounding rock.When the length is greater,the internal stress superposition of the anchor solid and the synergistic effect weaken.With the increase of the diameter of the rock bolt,the internal stress superposition area of the anchor solid,the stress value of each monitoring point and the synergistic increment all increased,but the enhancement effect was not obvious enough.The rock bolt has a synergistic anchorage length.Using a reasonable anchorage length can make the stress value in the anchor solid at a high level and have a significant synergistic effect.(4)On the basis of detecting the loose zone of surrounding rock,the anchorage scheme of 28 return air downhill roadway in a coal mine in Henan Province is designed by using the deep roadway surrounding rock synergistic anchorage technology.The construction monitoring results show that the bearing capacity,anti deformation capacity and overall stability of the surrounding rock anchorage structure of the roadway have been significantly improved.This paper has 61 figures,22 tables and 90 references.