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Ji H.-G.,University of Science and Technology Beijing | Mu N.-N.,China Society of Engineering Blasting | Zhang Y.-Z.,University of Science and Technology Beijing
Meitan Xuebao/Journal of the China Coal Society | Year: 2013

Taking Yanbei Coal Mine of Huating mining area as background, precursory characteristics of acoustic emission and pressure for rock burst events in the course of mining were analyzed. The results show that acoustic emission and pressure in rock body of rock burst "source" present some related change law before rock burst, which exhibits obvious precursory characteristics and intercoupling model. "Pressor-quiet and depressurizing-active" model, it means that when the overall trend of pressure variation increases, acoustic emission goes into quiet period, conversely, when it decreases, the acoustic emission presents active. "Pressor and depressurizing quiet" model, namely, no matter the pressure goes up or down, acoustic emission always keeps in the quiet period. This feature and model can be used as distinguish basis to predict rock burst events. Source

Yu L.,China Society of Engineering Blasting
Journal of Railway Engineering Society | Year: 2015

Research purposes: The vibration amplification (motion at the top was amplified from the bottom motion) of general multistory buildings responding to blasting vibration was analyzed by monitoring structure response of different floors and observing the safety effect of blasting vibration. Additionally, the vibration allowable index for safety and comfort of residential buildings had been put forwardaccording to the usage state. Research conclusions: (1) When blasting vibration frequency was close to natural frequency of abuilding, the ground blasting vibration would be amplified in the upper portion of this multistory building, while blasting vibration frequency was well above natural frequency of the building, thevibration amplification of multistory building responding to blasting vibration would not easy occur. (2) According to the possibility of vibration amplification of multistory building responding to different vibration sources, suggestions were put forward that blasting vibration monitoring of different floors should be carried out if the building location was more than 100m away from explosion source, but only the vibrationof building bottom could be monitored under high frequency blasting vibration if the building was at a short distance of explosion source. (3) Safety values of controllingblasting vibration of different buildings were proposed according to requirements of building structural safety, decoration materialsafety and indoor comfort. (4) The research results can provide references for blasting vibration controlling in railway stonework blasting excavation. ©, 2015, Editorial Department of Journal of Railway Engineering Society. All right reserved. Source

Tao T.J.,University of Science and Technology Beijing | Zhang G.Q.,University of Science and Technology Beijing | Wang X.G.,China Society of Engineering Blasting
Rock Fragmentation by Blasting, FRAGBLAST 10 - Proceedings of the 10th International Symposium on Rock Fragmentation by Blasting | Year: 2013

The quarries of Fongmayu Iron Mine are located near local residents. The 29th Olympic Games were held in Beijing in 2008. For this reason, the local government asked for a vibration study to monitor and analyze the blast effect on the surrounding environment. In total, 120 vibration signal data were taken at Fangmayu Iron Mine under different surface conditions from April to June, 2008. The following were found: the value of actual monitoring data and predicted data were both below the level specified by the Blasting Safety Regulations (GB6722-2003). The safety division blasting method used in Fangmayu Iron Mine is feasible and safe. The vertical component of PPV is not always the largest one. So, the criterion is not always the vertical component of PPV but the maximum one, when predicting whether constructions will be destroyed by blasting vibration. © 2013 Taylor & Francis Group. Source

Wang X.G.,China Society of Engineering Blasting
Rock Fragmentation by Blasting, FRAGBLAST 10 - Proceedings of the 10th International Symposium on Rock Fragmentation by Blasting | Year: 2013

The current state of Chinese engineering blasting technology and their achievements are discussed in this review of the development of Chinese engineering blasting. Looking beyond the innovation and development of Chinese engineering blasting technology, the paper points out that the Chinese engineering blasting industry needs further investigation, and stresses that four new concepts (new techniques, new process, new equipment, new material) are the source and power for the promotion the development of engineering blasting technology in China. © 2013 Taylor & Francis Group. Source

Shen L.-J.,China Society of Engineering Blasting | Shen L.-J.,China Metallurgical Industry Planning and Research Institute | Ma A.-E.,China Aerospace Science and Technology Corporation | Wang X.-G.,China Society of Engineering Blasting | And 2 more authors.
Hanneng Cailiao/Chinese Journal of Energetic Materials | Year: 2014

To analyze and compare the thermal stability of commercial ammonium nitrate (AN) and homemade non-explosive and irrestorable fertilizer-grade ammonium nitrate (NEIFAN), the crystal transformation changes, thermal decomposition characteristics and adiabatic decomposition processes of AN and NEIFAN were studied by thermogravimetry(TG)-differential thermal analysic(DTA)-derivative thermogravimetry(DTG), differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). The curves of thermal decomposition temperature and pressure vs time, self-heating rate and pressure vs temperature for AN and NEIFAN under the adiabatic decompositions condition were obtained. The kinetic parameters(apparent activation energy and pre-exponential factor)of pseudo zero order adiabatic decomposition reaction for AN and NEIFAN were calculated. The results show that in comparison with AN, the crystal transformation peak at about 88℃ of NEIFAN disappears, revealing that NEIFAN has better thermal physical stability. The decomposition peak temperature of NEIFAN obtained by TA-DTA-DTG and DSC curves and the apparent activation energy of the pseudo zero order adiabatic decomposition reaction of NEIFAN obtained by ARC data are much higher than those of AN, indicating that NEIFAN has a higher heat-resistance ability than AN. Considering that the increase of physicochemical stability of NEIFAN is attributed to the joint action of inorganic and organic additives in NEIFAN. Source

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