Study on mechanical properties of surrounding rock and shaft safety pillar in exploitation of extremely thin reef

Abstract

In view of the engineering geological conditions of the extremely thin reef of platinum gold mine in South Africa, we researched the distribution of in-situ stress, seismic and fault, the relationship between UCS and loading and so on. On this basis, we delineated the shaft safety pillar by using 3D mining software, and analyzed the influence of safety pillar on shaft stability by using FLAC3D numerical simulation method. The results show that it is necessary to set up accurate safety pillars to ensure the stability of shaft even though the height of goaf is very small in the mining of extremely thin reef. Research shows that the safety pillar calculated by numerical simulation method is more accurate, which avoids the resources loss or poor security caused by the traditional method. It is easier to achieve the expression of two-dimensional plane, and is more convenient to calculate the volume amount of safety pillar. The research provides theoretical guidance for the mining design, and has important practical significance.