Stress Monitoring And Risk Prediction Of Rock Burst In Mianhuakeng Mine

In recent years,with the depletion of shallow resources in metal mines,mining has continued to advance.With the increase of mining depth,the phenomenon of rockburst continues to appear,which is harmful and difficult to predict.This article discusses the problem of rockburst in metal mines.Taking the 12-2 stope where Shaoguan City,Guangdong Province China Nuclear Jinyuan Uranium Industry Co.,Ltd.,where rockburst occurs frequently,as the experimental background,a combination of stress monitoring and FLAC3 D numerical simulation To achieve the effect of advanced prediction.Through on-site investigation,determine the size of the stope,record the location of different rocks,drill and grind various types of rocks,and use mechanical experimental instruments to perform split strength experiments,uniaxial compression experiments,and triaxial compression experiments.Mechanical parameters.After the above parameters are reduced and estimated by the Hawke-Brown strength criterion and the M.Georgi method,accurate and reasonable mechanical parameters are determined according to the actual situation.According to the above data,the FLAC3 D numerical simulation was performed on the 12-2 stope to obtain the current status of the excavation at the current stope and analyze the stress cloud diagram and displacement cloud diagram.The stress cloud point is determined by analyzing the stress cloud image excavated at this stage,and six sets of stress monitoring instruments are installed to the stope location corresponding to the stress cloud point for 38 days of stress monitoring.Compare the stress value of the numerical simulation of the monitoring point with the data of the stress monitoring instrument.Except for the failure of the No.2 machine,the data monitored by the other stress monitoring instruments are consistent with the numerical simulation;the No.1,No.5,No.6 machines are in the simultaneous stress surge on May 13 th confirmed the correctness of the simulated stress concentration.After the accuracy of the model was verified,the model was used to carry out the next stage of simulation excavation.After the excavation is completed,the stress cloud diagram and displacement cloud diagram of the model are analyzed again and the rockburst in the second stage of the stope is predicted as follows: the stress in the roof area near the contact surface is significantly concentrated,and the rockburst occurs there.The risk is the greatest;the stress value at both ends of the stope is large and the stress cloud diagram tends to become larger.The risk of rockburst at this place is second only to the roof area near the contact surface;the middle area of the roof has a small displacement change,but the stress cloud image It is more uniform,and there is a lower risk of rockburst compared to the two areas above.Finally,the reliability of the prediction is verified according to the actual mining of the mine,indicating that the prediction provides a guiding role for the mine's safe production.