Deterministic in-situ Block Size Estimation using 3D Terrestrial Laser Data

A large amount of armourstone is needed for the construction of breakwaters that protect harbors. Sharp tender price and optimized design require an accurate prediction of the blast yield of quarries selected for the production of armourstone. The Blasted Block Size can only be smaller than the In-Situ Block Size. In practice, the IBS is estimated based on mean discontinuity orientation and spacing values derived from scanlines recorded manually. Instead, we propose a novel approach: the voxel method. The voxel approach uses all discontinuities visible in the rock face. The discontinuities are extracted from laser scanning of the quarry face. Blast induced fractures are discarded and discontinuities that have a similar orientation and a close spacing are merged assuming that they belong to the same discontinuity plane and were wrongly split during the segmentation process. The potential of our method is demonstrated for a quarry in Benin.