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Yima, China

Cai W.,China University of Mining and Technology | Cai W.,Key Laboratory of Deep Coal Resource Mining CUMT | Dou L.-M.,China University of Mining and Technology | Li Z.-L.,China University of Mining and Technology | And 4 more authors.
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2014

As the depth and intensity of coal mining increase, rockbursts have been common security issues in coal mines. For solving the difficult problem of the spatio-temporal forecasting of rock bursts, the method of the spatio-temporal forecasting for rock bursts was further developed using microseismic multidimensional information (MMI). First, the index system of MMI identification was established, including the preferred index about the frequency and the proposed indexes about the hypocenter concentration,the maximum and total equivalent stresses. Secondly, the temporal sequence curves and the spatial contour nephograms of each index were obtained based on the normalization method, the classification scriteria of anomaly, and the spatially and temporally statistical smoothed model. Moreover, the score method of R-value was adopted to evaluate and verify the forecasting efficiency of each index, and further determine the weights for each index.Finally,using the method of comprehensive anomaly index, the dangerous state, the specific hazardous areas and levels of rock burst were quantitatively analyzed in real time for the monitoring area. A forecasting example shows that this method has considered the microseismic time-space-strength factor, and played a better prediction on the rock burst.Specifically, it can quantitatively describe the dangerous state of rock burst for the monitoring area in time; reflect the hazardous areas and levels of rock burst in space; and guide the implementation of the measures to control rock burst in the field.Therefore, this study can, to some degree, solve the blindness in implementing the measures to control rock burst, and further develop the approach to monitor and forecast rock burst in space and time. Source

Zhao S.-K.,China Coal Research Institute | Zhao S.-K.,Zhejiang University | Liu J.,Yima Coal Group Co. | Wei X.-Z.,Yima Coal Group Co. | And 3 more authors.
Journal of Coal Science and Engineering | Year: 2013

In order to analyze the mechanism of deep hole high pressure hydraulic fracturing, nonlinear dynamic theory, damage mechanics, elastic-plastic mechanics are used, and the law of crack propagation and stress transfer under two deep hole hydraulic fracturing in tectonic stress areas is studied using seepage-stress coupling models with RFPA simulation software. In addition, the effects of rock burst control are tested using multiple methods, either in the stress field or in the energy field. The research findings show that with two deep holes hydraulic fracturing in tectonic stress areas, the direction of the main crack propagation under shear-tensile stress is parallel to the greatest principal stress direction. High-pressure hydraulic fracturing water seepage can result in the destruction of the coal structure, while also weakening the physical and mechanical properties of coal and rock. Therefore the impact of high stress concentration in hazardous areas will level off, which has an effect on rock burst prevention and control in the region. © 2013 The Editorial Office of Journal of Coal Science and Engineering (China) and Springer-Verlag Berlin Heidelberg. Source

Dou L.-M.,China University of Mining and Technology | Cai W.,China University of Mining and Technology | Gong S.-Y.,China University of Mining and Technology | Han R.-J.,China University of Mining and Technology | And 2 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2014

On account of increasingly frequent rock burst hazards at present, the theoretical basis of rock burst determination through P-wave velocity was analyzed based on the experiment relation model of stress and P-wave velocity. Meanwhile, the technology of rock burst risk assessment was established through seismic computed tomography detection, which contains assessment parameters of wave velocity anomaly An and wave velocity gradient anomaly VG. The criterion of these parameters was documented. Finally, the assessment technology was verified by practical application. The results show that P-wave velocity reflects the strength criterion, energy criterion and dynamic load criterion for rock burst as for the rock mass with the same properties. The seismic computed tomography detection technology is feasible for rock burst risk assessment. It can give guidance on the implement of risk relief measures and check the effect of the measures. Source

Zhao S.,China Coal Research Institute | Ouyang Z.,China Coal Research Institute | Liu J.,Yima Coal Group Co. | Zhang G.,Yima Coal Group Co. | And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

According to the analyzation of the process and influence factors of advanced deep hole blasting, its prevention and control mechanism for rock burst was demonstrated. The prevention effect was studied by changing the angle of blasting hole and the length of charge weight with ADINA numerical simulation software and its field practice effect was approved by different detecting methods from stress field and energy field. When the depth of the blast hole certain, the peak stress of high stress areas before workface reduce or transfer to deep coal at the three blasting hole arrangement in sector, which make the whole structure of coal-rock in a relatively stable low state. Furthermore, the angle of blasting hole larger and the length of charge longer, the shear stress decreasing zone bigger and the effect of rock burst control more obvious. Source

Hu W.,Henan Polytechnic University | Hu W.,Yima Coal Group Co. | Tang J.,Henan Polytechnic University
International Journal of Automation and Computing | Year: 2016

A kind of adaptive sliding model control algorithm is developed to solve and improve the mathematical model dependency and un-modeled dynamics of a controlled system. The control strategy derived from a kind of data-driven control method in essence, thereby the input and output data are utilized by the controller with no information about the control system model. Theoretical analysis proves that this proposed control algorithm can improve the utilization of the estimated pseudo partial derivative information and accelerate the velocity of the convergence. The stability of the control system is further verified by rigorous mathematical analysis. This new discrete-time nonlinear systems model-free control algorithm obtained better control performance through the simulations for the linear motor position and the information tracking speed, which also achieved robust and accurate traceability. © 2015 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg Source

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