Study on criteria of rock burst risk prediction in highway tunnels

Author(s):  
Xiaopeng Li ◽  
Jubing Zhang ◽  
Meifeng Cai
2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yarong Xue ◽  
Dazhao Song ◽  
Zhenlei Li ◽  
Jianqiang Chen ◽  
Xueqiu He ◽  
...  

Aiming at problem of low efficacy of early warning of rock burst in coal mine, a multisystem and multiparameter integrated early warning method based on genetic algorithm (GA) is proposed. In this method, firstly, the temporal-spatial-intensity information of energy incubation process of rock burst is deeply mined, and the multidimensional precursory characteristic parameter system of rock burst is constructed. Secondly, the genetic algorithm is used to train the historical monitoring data to obtain the optimal critical value and fitness value of each precursory characteristic parameter, and then the early warning index WC of each monitoring system is calculated. Finally, the integrated rock burst early warning index IC is obtained by synthesizing the early warning index WC of each system. The value of IC corresponds to the specific rock burst risk level of the mine. This method is applied to Wudong coal mine in Xinjiang, China. Based on the actual situation of the mine, a multidimensional precursory characteristic parameter system of rock burst is constructed, which includes energy deviation (DE), frequency ratio (Fr), frequency deviation (DF), degree of dispersion (DS), and total high value of energy deviation (DH). After analyzing the rock burst danger status and risk level in the monitoring area, the early warning capability of this method is found to reach 0.896. Combining with the specific prevention and control measures corresponding to different rock burst risk levels, it can provide effective guidance for the field work.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shitan Gu ◽  
Zhimin Xiao ◽  
Bangyou Jiang ◽  
Ruifeng Huang ◽  
Peng Shan

Stress concentration caused by tectonic stress and mining disturbance in coal mines induces a unique type of rock burst. No. 3201 working face controlled by an anticline structure in the Shandong mining area is used as the research background. The formation mechanism for anticlines is analyzed. Theoretical research shows that the bigger the tectonic couple is, the smaller the foundation stiffness, and the greater the bending degree and elastic strain energy of the coal will be. The distribution characteristics of abutment pressure and maximum principle stress in anticlinal control areas are analyzed using UDEC numerical software. The results show that rock bursts result from interactions between abutment pressure and residual tectonic stress. The “connection-overlay-separation” phenomenon of abutment pressure presents with working face advancement. Furthermore, the energy criterion for rock burst initiation is established based on the energy principle. Residual energy “E0−EC” and rock burst danger characteristics during mining are discussed. Based on the simulation results, microseismic monitoring data for No. 3201 working face are analyzed, and the law of microseismic energy is consistent with the variation law for the residual energy “E0−EC” at the peak of the simulated abutment pressure. The microseismic energy and frequency are higher during mining, increasing the risk of rock burst events. It can provide scientific basis for prevention and control of rock burst.


2020 ◽  
Vol 13 (11) ◽  
Author(s):  
Zhiqiang Li ◽  
Yiguo Xue ◽  
Shucai Li ◽  
Daohong Qiu ◽  
Lewen Zhang ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Dongming Guo ◽  
Xinchao Kang ◽  
Zhiying Lu ◽  
Qiyu Chen

According to the characteristics of rock burst of high horizontal stress roadway floor, the rock burst mechanism of roadway floor was studied with the background of south track roadway Xing’an mine. Based on the deflection theory and energy principle of the slab, the mechanical model of the floor of the roadway under high horizontal stress was established, the stress and energy criteria of rock burst occurred in the floor of the roadway were deduced, the prevention and control measures of the floor pressure relief with large diameter borehole and concrete-filled steel tube pile support were put forward, and the key parameters were determined. By establishing a numerical model, the evolution law of plastic zone, horizontal stress, and elastic strain energy density of roadway floor with or without support is contrastively analyzed. The results show that the effective means to prevent and control the floor rock burst is to cut off the stress transfer path by weakening the hard floor to reduce floor energy accumulation so as to reduce the floor rock burst risk. Based on the above research, field tests were carried out, and the microseismic monitoring results showed that the floor pressure relief of large diameter boreholes and concrete-filled steel tube pile support effectively relieved the floor rock burst and guaranteed the safety and efficiency of roadway excavation. This technology can provide a reference for the prevention and control of floor rock burst of similar roadways.


2014 ◽  
Vol 628 ◽  
pp. 383-389 ◽  
Author(s):  
Ya Hui Peng ◽  
Kang Peng ◽  
Jian Zhou ◽  
Zhi Xiang Liu

Due to the complex features of rock burst hazard assessment systems, a support vector machine (SVM) model for predicting of classification of rock burst was established based on the SVM theory and the actual characteristics of the project in this study. The main factors of rock burst, such as coal seam, dip, buried depth, structure situation, change of pitch angle, change of coal thickness, gas concentration, roof management, pressure relief and shooting were defined as the criterion indices for rock burst prediction in the proposed model. In order to determine reasonable and efficient the parameters of SVM, Firstly, the appropriate fitness function for genetic algorithms (GA) operation was determined, and then optimization parameters of SVM model were selected by real coded GA, therefore, the genetic algorithms and support vector machine (GSVM) model was established. A GSVM model was obtained through training 23 sets of measured data, the cross-validation method was introduced to verify the stability of GSVM model and the ratio of mis-discrimination is 0. Moreover, the proposed model was used to predict 12 new samples rock burst, the correct rate of prediction results is 91.6667% and are identical with actual situation. The results show that the genetic algorithm can speed up SVM parameter optimization search, the proposed model has a high credibility in the study of rock burst prediction of risk classification, which can be applied to practical engineering.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Ji ◽  
Hong-jun Guo ◽  
Yi-dong Zhang ◽  
Tao Li ◽  
Lin-sheng Gao

In order to reasonably evaluate the risk of rock bursts in mines, the factors impacting rock bursts and the existing grading criterion on the risk of rock bursts were studied. By building a model of hierarchic analysis method, the natural factors, technology factors, and management factors that influence rock bursts were analyzed and researched, which determined the degree of each factor’s influence (i.e., weight) and comprehensive index. Then the grade of rock burst risk was assessed. The results showed that the assessment level generated by the model accurately reflected the actual risk degree of rock bursts in mines. The model improved the maneuverability and practicability of existing evaluation criteria and also enhanced the accuracy and science of rock burst risk assessment.


2018 ◽  
Vol 37 (3) ◽  
pp. 1469-1481
Author(s):  
Zhongping Guo ◽  
Hengze Yang ◽  
Wenwu Xie ◽  
Weizhen Liu ◽  
Chao Wang

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