We develop a dot matrix method (DMM) using the principles of computational geometry to place aggregates into matrices for the construction of mesolevel concrete models efficiently and rapidly. The basic idea of the approach is to transform overlap detection between polygons (or polyhedrons) into checking the possibility of any intersection between the point sets within a trial placement aggregate and the already placed ones in mortar. Through the arithmetic operation of integer point sets, the efficiency of the underlying algorithm in the dot matrix method is higher. Our parking algorithm holds several advantages comparing with the conventional placement issues. First, it is suitable for arbitrary-shape aggregate particles. Second, it only needs two sets for examining if the overlap between a trial placement aggregate and the already placed ones. Third, it accurately places aggregates according to aggregate grading curves, by order of reduction, led to more efficiently reducing aggregate placement time. The present method is independent of the size of aggregate particles. Combing with 3D laser scanning technology, the present method can also be used to create mesostructure concrete models conveniently and flexibly. Several examples show that DDM is a robust and valid method to construct mesostructure concrete models.

Landslides often occur in the open-pit mine dump, which is harmful to the safety operation of mines and slopes. In this work, the landslides that occurred in 2014 at Nanfen open-pit mine of China are studied to understand the triggering mechanism and dynamic process of landslides in the full high waste dump. Field investigation, hydrogeological data analysis, satellite map data, and numerical simulation are combined to analyze and evaluate the landslides. The study shows that the continuous and intensive dumping can lead to shear failure under the action of self-weight. The shear strength of loose dump bodies significantly relies on the water content, freeze-thaw cycle, pore pressure, and gradation of the dump soils. These factors result in the occurrence of landslides in the dump slope. The predictions by the smoothed particle hydrodynamics method show that the shape, influence range, and slip distance of landslides are consistent with that of the field investigation. The present study shows that the SPH method is a powerful numerical technique to describe landslides’ problems.