Calculation models for parameters of spherical charge blasting shock wave considering ambient temperature and humidity

In this study we firstly calculated the parameters of equation of state (EOS) for ideal gas considering temperature and relative humidity to obtain the calculation models for parameters of the blasting shock wave in ambient temperature and humidity. Then, we established the spherical charge model using the SPEED software to simulate the blasting processes in typical air conditions. The results show that the temperature and relative humidity have little influence on the shock wave overpressure, and that both the positive phase duration and the impulse, which are 21.8% and 18.4% smaller in high temperature and humidity than those in the cold and dry air, respectively, decrease linearly with the increase of the temperature and relative humidity. Furthermore, based on classical engineering calculation models, we established the calculation models for the shock wave parameters in spherical charge blasting considering ambient temperature and humidity by introducing correction factors such as temperature, relative humidity and scaled distance. From these models we obtained the blasting shock wave parameters with different doses of spherical TNT. The parameters were found quite consistent with those from numerical simulation, thereby suggesting that the calculation models can serve as reference for power assessment in real environments.