Development of a geological model for chargeability assessment of borehole using drill monitoring technique

Blastability and Ore Grade Assessment from Drill Monitoring for Open Pit Applications

“…Systematic variations generated by the drilling system and external influences other than the rock can be recognized and removed by averaging, for a large amount of data, the logged response (Schunnesson 1998). Procedures to normalize parameters to reduce external influences in the rig response have been described by Schunnesson (1998) for percussive drilling, Ghosh et al (2018) and Navarro et al (2019) for Wassara water-hydraulic ITH (in-the-hole) drilling in underground production operations, and Hjelme (2010) and Navarro et al (2018) for rotary-percussive drilling in tunneling works. However, no such analysis has been published for open pit operations.…”

“…Schunnesson (1998) claimed that when discontinuities or changes in the geotechnical rock condition are found, penetration rate and rotation pressure parameters show significant fluctuations, resulting in a noisy signal. Schunnesson (1997) for rotary-percussive drilling and Ghosh et al (2018) for Wassara ITH hammer, demonstrated an increase in the fluctuation of the penetration rate and rotation pressure when drilling through a fractured zone. These variations are (1) where PR var is penetration rate variability, RP var is rotation pressure variability, N is the window size and is considered N = 4 (Ghosh 2017), PR i and RP i are the average values of the respective parameters within the window N, i is the sample number, L is the number of sample points of the MWD signal, and PR i and RP i are the penetration rate and rotation pressure, respectively, at each sample i.…”

“…Taking Ghosh et al (2018) work as starting point, PCA have been used to correlate penetration rate, percussive pressure, feed pressure and normalized rotation pressure parameters, plus the calculated penetration rate variability, rotation pressure variability and the DI. The PCA is a method used to reduce the dimensionality of a multivariable dataset, while preserving as much 'variability' (i.e.…”

“…About MWD interpretation on the structural rock condition, for rotary-percussive drilling, Schunnesson (1997) proposed a methodology to estimate the RQD index based on the penetration rate and torque pressure, and their variation, that shows a close correlation with the presence of discontinuities; Peng et al (2005) and Tang (2006) developed a method to measure void/fractures in tunnel roofs from bolt drilling; van Eldert et al (2020) correlated the MWD data to the RQD index and suggested an approach on the use of this technology for rock support design to improve cost efficiency in tunneling projects. For Wassara water-hydraulic ITH (in-the-hole) drilling, Ghosh et al (2018) and Navarro et al (2019) developed a probabilistic geotechnical rock classification model for fan-shaped long-holes drilling in underground production operations.…”

Quantitative Detection of In‐Service Strength of Underground Space Strata considering Soil‐Water Interaction

“…eoretical drilling mechanics models have been developed for various drill bits, including roller bits, impact bits, cutting bits, and polycrystalline diamond compact bits [2][3][4][5][6][7][8]. Experimentally, the relationships among drilling parameters (e.g., torque, propulsion, revolution speed, and penetration rate) have been studied [9][10][11], while the relationships between drilling parameters and rock physics as well as mechanical parameters (i.e., stiffness, cohesion force, shear strength, and density) have been revealed [12][13][14][15]. In terms of field applications, evaluations of rock grades, investigations of rock rupture regions, and evaluations of the drillability of rock and rock-like materials have been conducted [16][17][18][19][20][21][22].…”