| The stability of surrounding rock in gold mine has become the mostimportant issues in mine security. Because of the discontinuity, heterogeneity,anisotropy, and occurrence difference of rock, it is difficult to predict theinstability accurately. As the result, it has significant economic and social benefitsto study the instability rules of surrounding rock and present the alarm threshold.According to the requests of XiaDian Gold mine, the stability of mining stope wasstudied based on the stability of tunnel roof.Choosing the No.536+6and537mining stopes as the study objects, thispaper studied the stability of tunnel surrounding rock and the mining stopesinfluenced by the excavation of gold mine stopes. Based on the Fiber BraggGrating (FBG) bolt monitoring technology, through the numerical simulation,theoretical analysis and simulation model experiment, the surrounding rockstability and the developing rules of FBG signals during the process of damagewere studied. The main work is:Firstly, using the FLAC3D, the characters of mechanical fields, displacementfields and failure fields were studied and the stability of tunnel surrounding rockduring the excavation of the mine stopes was analyzed. At the same time, theposition of mining stope was optimized.Secondly, catastrophe theory was used to analyze the energy band during theexcavation and as a result, alarm threshold equation was given out whoseparameters were length, rock strength, stress states and so on. Then using thisequation, the stability of mining stope was analyzed and the theoretical resultswere compared with the numerical results.Finally, based on the FBG and combing with the actual condition of thestructure laboratory, a model experiment was carried out to study the signals’characters of the FBG wavelength. The results of model experiment werecompared with the theoretical and numerical results, and the characters ofwavelength under different surrounding pressure and different cracks.Based on the analysis above, this paper shows the stability of mining stopesduring the excavation. Using numerical analysis, the transfer trend of stress anddisplacement in several models with different tunnel length were studied, andresults showed that the best length of the tunnel was6m. When the alarm threshold equation was shown, parameters in the equation were reduced and as aresult, the equation became more convenient to use in actual project. After themodel experiment was finished, the FBG results were also compared with theresults of theoretical analysis and it can be seen that the two results were the same. |
PDF Full Text Request