## 1 Introduction  
Rock breakage through blasting has been regarded as a cost-effective and efficient technique in surface mines, civil excavations, and tunnelling works [1, 2]. The process of blasting utilizes the chemical energy stored in explosives to generate pressure on the rock mass, which ultimately leads to its breakage and heaving. However, approximately 70% of the total available energy generated by the detonation of explosives is lost in the form of undesirable outcomes, such as ground vibration, air overpressure, back-break, and flyrock [3, 4, 5, 6]. Among these, flyrock is one of the most dangerous manifestations of unutilized explosive energy, as it has the potential to damage nearby structures, human beings, materials, and equipment located in close proximity to the blast site [7]. Flyrock refers to fragmented rock particles of various sizes and shapes originating from the blasting patch and experiencing excessive throw or movement to reach outside the designated blasting safety zone due to the unanticipated force of the explosive [8, 9]. [PERSON] [9] categorized the terminology related to flyrock into three classes, the first being 'throw', which is the planned forward movement of rock fragments to create a muck pile; the second is 'flyrock', which is an unsught propulsion of broken rock fragments aerailly beyond the blast zone, and the third is 'wild flyrock' which is a flyrock generated due to a combination of factors that is not well understood. According to accident statistics published by the DGMS, India,deep-hole-blasting projectiles and solid-blasting projectiles account for approximately 42% of fatalities in coal mines and approximately 17% of fatalities in non-coal mines, highlighting flyrock as a significant hazard in opencast blasting. Therefore, there is a need to study the factors influencing flyrock in opencast blasting so that the design parameters can be optimized to predict and control its occurrence. Figure 1 shows flyrock observed in one of the bench blasts studied in this research work. Flyrock occurs as a result of the release of energy from the explosion, particularly in the form of high-pressure gases that radiate through fractures around the blast hole due to mismatches between the geotechnical properties of the surrounding rock mass, the size of the block to be thrown, the distribution of explosives, and the degree of confinement. It has been explained by various researchers [7; 10; 11; 12] that there are primarily three modes of flyrock generation: face bursting, cratering, and rifling, as depicted in Figure 2, wherein it can be observed that due to the location from where the launch occurs from the bench, cratering and rifling can result in flyrock in any direction, whereas face burst is more likely to generate flyrock in the direction of the free face only. Face burst is typically caused by an insufficient burden or soft geological formations [9], whereas inefficient stemming material and inadequate stemming to burden or stemming to blashhole diameter ratio lead to cratering and rifling [3; 12; 13]. Studies indicate that the factors influencing blast-induced flyrock are categorizable as controllable and uncontrollable factors [14; 15; 16]. Controllable factors largely include blast design variables which can be altered and controlled by the blasting engineers. In contrast, parameters including rock mass characteristics, geotechnical conditions, local topography,  
Figure 1: Flyrock observed in one of the bench blasts studied in this research work. Figure 2: Three modes of flyrock generation in bench-blasting operations. properties of flying fragments (such as launch velocity, size, density, shape, and orientation in relation to velocity vector), wind conditions, and environmental constraints are beyond the purview of blasters' influence and are thus uncontrollable. The distance, trajectory, and dispersion of flyrock are shaped by intricate interactions between controllable and uncontrollable factors.