Instability Mechanism And Engineering Application Of Anchor Solids With Different Anchor Lengths Under Coupling Effects Of Temperature And Pressure

Resin bolt active support is widely used as an effective technology to control the stability of roadway surrounding rock.However,with the increasing depth of coal mining,the problems of high ground temperature and high ground stress in deep stratum are prominent,which leads to the instability of roadway surrounding rock and the failure of supporting structure from time to time,which seriously threatens the safety of mine production.Therefore,this paper takes Dingji Coal Mine deep well soft rock roadway support engineering as the research background,and carries out the research on the deformation mechanism and engineering application of resin anchor solid with different anchorage lengths under the action of temperature and pressure coupling.By combining theoretical analysis,indoor drawing test,similar model test,numerical simulation and field measurement,this paper systematically studies the stress transfer law and distribution characteristics of anchor solids under the combined action of different temperature conditions,stress environment,strength of surrounding rock and anchoring length,as well as the deformation,fracture and instability mechanism of anchor solids.The main contents and results are as follows:(1)Based on the simplified shear-slip model,a mechanical model of load transfer in anchoring section is established.Considering the influence of temperature,lateral pressure coefficient,strength of surrounding rock and anchoring length,the interfacial shear stress of anchoring agent-surrounding rock and the axial force equation of anchor bolt in the elastic-plastic stage are obtained.(2)Drawing tests of different anchoring lengths were carried out to simulate different ground temperature,different lateral pressure coefficient and strength conditions of surrounding rock,and the load transfer law of bolt was obtained in the drawing process.The results show that the factors affecting the degree of ultimate anchoring force are: anchoring length > surrounding rock strength >ambient temperature > lateral pressure coefficient,and the empirical calculation formula of ultimate anchoring force is obtained.(3)Based on the principle of sisification theory,a full-length deformation and failure simulation test system for anchor solids under the coupling effect of temperature and pressure was constructed,and the relationship between the failure characteristics of anchor solids,temperature and side pressure coefficient was obtained through the experimental study.(4)FLAC3D numerical analysis software was used to establish the numerical analysis model of solid load transfer of anchor under drawing state.The distribution characteristics of axial stress of anchor under different anchoring lengths,temperatures,lateral pressure coefficients and surrounding rock strength were obtained by orthogonal design.The calculated values were in good agreement with the laboratory test results.At the same time,the plastic failure process of anchor solids with different anchoring lengths under temperature-pressure coupling was simulated,and the plastic failure characteristics of anchor solids were obtained.(5)Based on the engineering background of track channeling rock roadway in1232(3)working face of Dingji Coal Mine,Huainan,based on the results of test and numerical simulation,the length of roadway bolting support is optimized.The mine pressure monitoring shows that the deformation control effect of surrounding rock is good after lengthening anchorage,which ensures the stability and normal use of the roadway.The research results can provide technical reference for the optimization of anchorage support parameters of deep shaft roadway.Figure [49] Table [9] Reference [78]...