Study On The Influence Of Plateau Environment On Explosive Performance

In recent years,with the proposal of China’s "Belt and road" policy,the construction of plateau projects has gradually increased.The unique objective conditions,such as cold and anoxic climate,the harsh natural environment,difficult road transportation,and low utilization rate of machinery,make plateau construction have significant characteristics and laws different from other project construction.From the perspective of blasting construction,in the plateau environment of "fast temperature change,low oxygen content and low air pressure",ensure that explosives can still detonate stably in this specific environment,which can not only ensure the blasting quality,but also improve the health and life safety of blasting personnel.In order to study the variation law of explosive explosion performance in plateau environment,this paper preliminaries obtained its explosion parameters(detonation velocity,violence,overpressure)by conducting explosive explosion performance test experiments under different pressure and temperature conditions in a self-developed large 5kg TNT equivalent spherical explosion container,and obtained relevant data on plateau blasting through field investigation,and obtained the following main conclusions:(1)The reduction of pressure has a certain effect on the explosive performance of the emulsion explosive.With the continuous reduction of environmental pressure,the detonation velocity of plastic film packed emulsion explosive shows a trend of first increasing,then decreasing and then increasing,with an overall increase of 6.59%,which is not obvious;The emulsion explosive with PVC shell showed a trend of first increasing and then decreasing,with an overall increase of 12.63%;The brisance of emulsion explosive decreased first and then increased,and the overall compression increased by 20.4%.The performance change of emulsion explosive may be caused by the expansion of hot bubbles in the explosive due to the change of pressure,which results in more effective bubbles or bubbles breaking,thus increasing or decreasing in number;With the decrease of pressure,the physical form of emulsion explosive changes and the density decreases.(2)The decrease of temperature has a certain effect on the explosive performance of the emulsion explosive.With the decrease of temperature,the detonation velocity of the chemically sensitized emulsion explosive decreases with the decrease of temperature,and finally decreases by16.52%;the brisance of emulsion explosive showed a downward trend,and finally decreased by26.25%.The change of detonation velocity and violence of emulsion explosive is mainly due to the change of the free energy on the surface of the bubble and the pressure difference between the inside and outside of the bubble at a low temperature.At the same time,the cavity of the explosive interface film will become larger and larger due to the low temperature,resulting in emulsion breaking,crystallization and other phenomena of the emulsion explosive.(3)The elevation will have a definite impact on the explosive performance and shock wave parameters of emulsion explosives.With the increasing altitude,the detonation velocity of the chemically sensitized emulsion explosive shows a downward trend,and decreases by 11.95% at4500m;The numerical value of shock wave overpressure of chemically sensitized emulsion explosive shows a downward trend,and when it reaches 4500 m,it decreases by 17.94%,showing a certain regularity,which well conforms to the theoretical calculation formula of explosive explosion shock wave overpressure under low temperature and low pressure environment.(4)Based on the field practice records of Yulong Copper Mine in Tibet,taking the Erzhuoma oxidized ore blasting project as an example,the blasting related parameters are analyzed,and some problems in plateau blasting are summarized,such as misfire problem,explosive explosion performance problem,explosive density problem,frozen soil problem,block rate problem,etc.