Evaluation of seismo-acoustic hazards from cement quarry blasts on the New Administrative Capital, Egypt

Abstract

Cement industry is one of the strategic sectors in Egypt. In most cases, cement factories are using explosives to obtain the materials needed for the industry. Such activities pose threats to the surrounding environment. The threats are more serious when the quarries are located near to a strategic site. The New Administrative Capital (NAC) is one of the leading development projects in Egypt that happen to occur close to some cement quarries that use explosions to obtain the raw materials. Possible unfavorable effects are expected on the buildings and projects at NAC. To evaluate these effects and to propose measures to ensure the safety of NAC structures, the present work was carried out. Threats expected are due to both ground motion and air over pressure. The methodology adopted in the study was based on monitoring the explosions, ground motions, and air over pressure. The monitoring was conducted using temporary arrays that were deployed in the explosion day. The time period required is almost 2 years. Furthermore, the collected data were processed to reject low quality data. The processed data were modeled in terms of the international standards to determine the threshold level of hazards for both ground motion and air over pressure. The work is finally summarized in terms of model equations in terms of the scaled distances. The choice of the scaled distances was to simplify the model by eliminating the effect of the charge per delay parameter. The final results showed that keeping the charge weight per delay under 45 kg, threats at a distance of 7 km is vanished. The model showed also that the effect of air over pressure is higher with scaled distances than the ground motion. To the best of our knowledge, the present work is the first of its kind in Egypt. Also, it is recommended to study the frequency effect of both parameters and to account for the effects of the site on the ground motion.