In order to ensure the safety of explosive charged in underground cavern during the transition of opencast-underground combined mining, the safety effect of charged explosive under the surface blasting is analyzed by field measurement, theoretical analysis and numerical simulation from the aspects of heat sensitivity, mechanical sensitivity, detonation sensitivity, shock sensitivity. The software ANSYS/ LS-DYNA was applied to simulate and assess the influence of surface blasting seismic wave on the caverns. Based on the seismic wave data collected from IDTS3850, Sadov's formula was used and the wave's declination of surface blasting vibration in vertical direction was concluded. The results show that the heat induced from surface blasting is not enough to trigger the loaded explosive, blasting vibration wave cannot make the underground caverns collapse, the pressure from blasting vibration wave reaching the caverns is not strong enough to detonate the explosive.
More than 80% ore in China's metallurgical mines come from opencast mining. After decades of mining, most of large and middle scale opencast mines in our country has entered the later period during the eleventh five-year plan, mining methods have changed from the hillside mining to deep mining, mining is or has been faced with the mining into underground mining stage (Ren 2011). Some domestic and foreign experts have researched on the safety of underground engineer during opencast- underground combined mining, Fowrie and Green (Xiong 2002) through the analysis and research of the four underground coal mine monitoring data, summary the vibration of the underground monitoring is significantly affected by The maximum period of explosive during each quick-fried bore blows up when the explosive source is directly above the long-distance monitoring points. Bian Kexin (Bian 1981) works out the evaluation methods and standard of blasting vibration on the stability of mine on the basic of analysis and discussion of blasting vibration on damage and failure characteristics of underground structures, but the safety effect of charged explosive in loaded carven under the surface blasting is rarely analyzed. Due to more charged explosive in loaded carven and close the earth's surface are great danger under opencast-underground combined mining, so it is necessary for research.
