OFFICIAL =ඨ 2(1+ ) (9) Where: E = Young's Modulus (GPa) μ = Poisson’s ratio ρ = Density (Ton/m3) Under this same framework, the concept of the presplit filter is defined. This is described as the wave attenuation resulting from the discontinuity plane formed by the presplit blast. CASE STUDY This study arises from the necessity to evaluate presplit efficiency in a rock mass via numerical modeling, aiming to optimize design parameters and minimize operational risks associated with blasting. The primary objective is to compare the performance of a lowdensity explosive, commonly utilized in regional mining, across two diameter configurations: 1 1/2" and 1 1/4", specifically regarding the generation of the presplit tensile fracture. To achieve this, borehole spacings of 1.2 m, 1.5 m, and 1.8 m will be evaluated, using the 1.5 m spacing as the baseline design. The blasthole diameter is fixed at 5", resulting in decoupling ratios of 3.33 and 4.00, respectively. For this purpose, geomechanical properties of the intact rock and explosive technical specifications were collected; these serve as the input data for the numerical model and are presented in Table 1 and Table 2. Table 1; Geotechnical parameters of rock used in the simulation. INTACT ROCK Unity Values Young's Module Gpa 8.84 Poison’s Ratio - 0.19 Rock Density tom/m3 2.78 UCS Mpa 135.8 Tensile strength Mpa 16.5 RMR - 55 GSI - 50
RkJQdWJsaXNoZXIy MTM0Mzk2