###### Abstract  
Stemming has a major impact on energy containment inside a blasting hole and is essential for increasing the efficacy of explosive charges in rock blasting. This method is essential in many fields, including road project development, mining, tunneling, and underground construction. By fortifying the confinement of the energy generated by a loaded explosive charge in a blasting hole, stemming increases the fragmentation of rock. Improper or missing stemming leads to the gas escaping in advance from blast holes, resulting not only in the wastage of explosive energy and poor fragmentation but also in environmental problems such as ground vibration, noise, flying rocks, back breaks, and air blasts. When the process to keep gases inside blast holes is not performed correctly or is skipped, it can waste explosive energy and produce poorly fragmented rocks. This also causes problems like high ground vibrations, loud noise, flying rocks, cracks behind the blast area, and strong air shocks. In this study, a shock chamber blasting experiment and numerical analysis were conducted to evaluate the pressure confinement effect of stemming material and plug devices in a blast hole. The resulting stemming effect was compared with that of a shear-thickening fluid (STF)-based stemming material currently under development and sand, which is a commonly used blast stemming material. To evaluate the enhancement of the confinement effect inside the pressurized blast hole, three types of stemming plugs were adopted. The blasting experiment and numerical simulation results revealed that the STF-based stemming materials were superior to conventional stemming materials. In addition, the STF-based stemming and plug system can prevent detonation gas from prematurely overflowing the borehole and effectively prolong the action time and scope of the detonation gas in the borehole. blasting experiment; numerical analysis; stemming effect; shear-thickening fluid; plug system +
Footnote †: journal: Medical Imaging  
0000-0001-8800-7800]H.H. Stemming provides the confinement of explosive energy for a longer duration than in a blast hole without it. The most important function of stemming is to maintain the explosive energy within a blast hole and reduce the energy loss from the borehole. Without stemming, up to 50% of the explosive energy can escape through the borehole [3]. Missing or improper stemming, which leads to detonation gas escaping from blast holes in advance, results not only in the wastage of explosive energy and poor fragmentation but also in environmental problems such as ground vibration, noise, flying rocks, back breaks, and air blasts [4]. Previous studies have demonstrated that stemming can lengthen the action time of detonation gases inside blast holes and accelerate explosives' full reactions, consequently reducing explosive consumption [5; 6]. In two experiments, [PERSON] [7] used a vented charge (no stemming) in one and a confined charge in the other (with stemming). For the latter, the P-wave before the compression pulse was discovered to be 20% longer, and the tailing tension pulse was 50% greater. Additionally, the tailing pulse duration increased by 30%. [PERSON] [7] also found that stemming improved the maximum crack radius at crack arrest by a factor of five compared with an unstemmed charge. Stemming, which maintains gas pressure over time, is used to enhance a blast's performance. Excellent stemming can effectively extend the action period and the range of the detonation gas in the borehole by preventing premature overflow of the borehole with the detonation gas. Additionally, a sizable portion of the rock mass develops cracks. The block size and distribution after blasting satisfy the construction requirements because these fissures spread throughout the rock mass, connect with one another, and cut the rock. Therefore, boosting the blasting impact, increasing explosive efficiency, and attaining optimal blasting fragmentation all depend on an understanding of how to determine stemming reasonably.