| Considering theshaft,tunnel and mining stope in metal mine, it is prone toroof subsidence,separation and crack due to the blasting effect and complex environment. As its deformationarriving to a certain extent, rock mass may fracture and roof may collapse. After reviewing thepast work and achievements, the stability of surrounding rock is diagnosed from the monitoringvibration signal in roof falling potential regional in the paper, and several tasks of researches aredeveloped in thisthesis as following:1. Wavelet transformation analysis is adapted to safety diagnosis of surrounding rock withthe blasting affection. A method for Wavelet transformation energy analysis is gained on thebasis of propagation characteristics of blasting stress wave in fractured rock and feature of stresswave refraction and reflection. The optimum wavelet base has been worked out anddecomposition level confirmed which is much more suitable for blasting vibration analysis.After that db7wavelet is successfully applied for vibration signal analysis monitored inDaoBeiZhuang Mine, and characteristics of the vibration signal are extracted form thebackground noise signal.2. Since response signals will change as blasting effect changes in the course of mutationfrom stability to instability, stability roof model and instability roof model are presented innumerical simulation based on blasting vibration. Considering the stress wave propagationcharacteristics, the wavelet frequency band energy is calculated to determine whether thesurrounding rock and roof is stable or not. Frequency band energy ratio and normalized energyratio are proposed for safety diagnosis, while blasting response signals of stable surroundingrock are needed for comparison.3. The similar model test includes the course from stable status to roof falling whichvibration signals surveillance is conducted by fiber Bragg grating sensor rock bolt. Signals inintegrated and crack rock roof under different confining pressure and different vibrationintensity are recorded for further analysis with wavelet transformation. Consequence, thewavelet frequency band energy and distribution features are gained while roof arrives at thestage of cracking andcollapsingAccording to the results of numerical simulation, model test indoor and theoreticalanalysis,two researches of example engineering project application are carried out, respectively at No.7 Mine and DaoBeiZhuang Mine in XiaDian Gold Mine. The blasting vibration monitoringresults are modification and empirical verification to the conclusions mentioned above. Theresults show that the study on stability diagnosis of rock mass based on wavelet transformationanalysis under blasting effect can be used to deal with real time data, so it is very suitable for thehealth monitoring andsafety diagnosis on shaft, tunnel and mining stope in gold mine. |
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