This work studies and evaluates the mechanical properties of frozen soil, FS, from Yulong mine in Tibet, under different freezing temperatures ranging from −12 °C to −1 °C, using experimental tests. In addition, the effects of temperature and time on the freezing depth of FS were investigated. Based on the cantilever beam theory, the mechanical model of FS breaking under blasting stress wave was established, and the theoretical formula for the fracture length (FL) of FS was deduced. Moreover, the major influences on FL were analyzed. The results showed that the frozen depth curves at different temperatures were approximately linear in single or double segments, and the lower the temperature, the greater the early freezing rate. Additionally, the uniaxial compression strength, elastic modulus, and tensile strength of FS were found to decrease with the increase in temperature. The findings highlight that the shear strength, cohesion, and internal friction angle decreased first and then increased with the increase in temperature. It was shown that the thickness, friction coefficient, weight density, and tensile strength of FS are positively correlated with the FL, while there is an inverse proportionality with respect to the pressure of the detonation wave.

An innovative approach utilizing 3D laser scanning technology has been introduced in open-pit mining for capturing spatial data of blast piles. RANSAC for plane fitting and DBSCAN for clustering are applied to outline rock block contours accurately. Quick calculation of rock block volumes and maximum particle sizes is enabled through 3D convex hulls and Oriented Bounding Boxes (OBB). Delaunay triangulation of 3D point cloud data is used to create a detailed mesh model for precise volume estimation of blast piles. Indoor testing revealed relative errors of approximately 4.61% for block volumes and 4.75% for particle sizes, while field applications showed an average rock block identification accuracy of 80.4%, increasing with block size. Estimated versus actual blast pile volumes showed a relative error of 4.85%, with computational errors for the pile's height, forward throw distance, and lateral extent being 2.92%, 3.91%, and 4.29%, respectively.

The precision of determining rock mass mechanical parameters is notably impacted by mining blast activities. An advanced method for inverse analysis of these parameters, predicated upon measured blasting vibrations, has been developed. This approach employs a meticulous recognition of initial P-wave and S-wave arrivals within the vibrational energy spectrum. Utilizing principles from elastic wave theory, a novel framework has been established, correlating P-wave and S-wave velocities with dynamic characteristics of rock masses. The efficacy of this method has been substantiated through practical implementation, particularly in the Guanbaoshan Open-pit Iron Mine, Liaoning Province. Here, the derived density ratios were observed to range between 0.98 and 1.01, aligning closely with figures provided by authoritative research institutes. Additionally, the dynamic-to-static Poisson's ratio exhibited variations from 0.85 to 1.03, while the modulus of elasticity ratio dynamically to statically spanned from 2.0 to 2.6. These results, falling within anticipated theoretical ranges, underscore the robust applicability and accuracy of this method. The research contributes significantly to the domain of mining operations, particularly in optimizing blasting processes and enhancing the precision of mechanical parameter acquisition. It presents a pioneering approach, essential for addressing similar challenges in the mining sector.