TIN clipping algorithm is one of the basic algorithms for digital mining design of open-pit coal mine based on TIN model. In this paper, a precise TIN clipping algorithm for digital mining design of open-pit coal mine is proposed. Based on the constructed grid index of the clipped TIN and the clipping polygon, the clipping polygon is embedded into the clipped TIN by interpolating the vertex elevation of the clipping polygon and calculating its intersections with the clipped TIN. Then, according to the reconstructed topology of the TIN triangles located inside (outside) the clipping polygon, generate the boundary of those two triangles set, and construct the TIN between the boundaries using the one-time edge-prior CDT growth algorithm, thus , achieve the precise TIN clipping keeping the clipped TIN’s local detail features. The experiment results show that the algorithm proposed in this paper is efficient, stable in performance, and it has been applied to the digital mining design of the open-pit coal mine.

The triangulated irregular network (TIN) clipping algorithm is one of the vital algorithms for the digital mining design of opencast coal mines based on the geological digital elevation model (DEM) described by TIN. This paper gives a precise TIN clipping algorithm applied in the digital mining design of the opencast coal mine. To improve the algorithm’s efficiency, a spatial grid index is built and utilized to embed the Clipping Polygon (CP) into the Clipped TIN (CTIN) by interpolating the CP’s vertices’ elevation and solving the intersections of the CP and the CTIN. After that, the topology of the triangles situated within (outside of) the CP is reconstructed, and then the boundary polygon of those triangles is obtained based on the reconstructed topology. Finally, a new boundary TIN between the CP and the boundary polygon of the triangles situated within (outside of) the CP is generated by applying the one-time edge-prior constrained Delaunay triangulation (CDT) growth algorithm, and the TIN to be clipped out is separated from the CTIN by topology modification. At that point, CTIN clipping is accomplished with the local details remaining. The algorithm has been programmed in C# and.NET. Additionally, it is also applied to the opencast coal mine digital mining design practice, and it is robust and highly efficient.

This article introduces a new method called Envelope Surface Model to establish 3D geological model of Surface mine fast, aiming to simulate 3D visual mining in surface mine. Firstly the method based on the establishment of 3D terrain Model and the 3D geological model of surface mine. The mining template is determined by actual production situation of surface mine, and realizes simulating surface mining by moving these templates to slice 3D models. And it is possible for the mining engineer to choose the better program from several design patterns, thus improve the speed and the quality of mining design by virtual mining process.

The triangulated irregular network (TIN) clipping algorithm is one of the vital algorithms for the digital mining design of opencast coal mines based on the geological digital elevation model (DEM) described by TIN. This paper gives a precise TIN clipping algorithm applied in the digital mining design of the opencast coal mine. To improve the algorithm’s efficiency, a spatial grid index is built and utilized to embed the Clipping Polygon (CP) into the Clipped TIN (CTIN) by interpolating the CP's vertices’ elevation and solving the intersections of the CP and the CTIN. After that, the topology of the triangles situated within (outside of) the CP is reconstructed, and then the boundary polygon of those triangles is obtained based on the reconstructed topology. Finally, a new boundary TIN between the CP and the boundary polygon of the triangles situated within (outside of) the CP is generated by applying the one-time edge-prior constrained Delaunay triangulation (CDT) growth algorithm, and the TIN to be clipped out is separated from the CTIN by topology modification. At that point, CTIN clipping is accomplished with the local details remaining. The algorithm has been programmed in C# and .NET. Additionally, it is also applied to the opencast coal mine digital mining design practice, and it is robust and highly efficient.

In this study, we present the coordination development schemes of mining and dumping engineering in steeper anticline region of an open-pit coal mine with nearly flat coal seam. Steeper anticlines in an open-pit coal mine with a nearly flat coal seam lead to drastic changes in local geological features and have many adverse effects on safe, economical, and efficient production. Based on an impact analysis of the anticline on the production quantity and quality of coal, release and utilization of the internal dumping space, layout of the haulage system and so on, the key technical solutions related to mining and dumping engineering coordination development in the steeper anticline region are discussed. Subsequently, taking the Antaibao Open-pit Coal Mine as a case study, based on the geological features of the steeper anticline region, two mining and dumping engineering coordination development schemes, the northern priority development scheme and the pseudo-longitudinal mining scheme, are proposed. Key technical parameters including the length and preceding distance of the priority development working-line, preceding distance and the horizontal advancing speed of the mining working line are determined. To compare the two proposed schemes in detail, the mining and dumping coordination development plans of the two proposed schemes during mining over the steeper anticline region are worked out, and some technical indices are computed. Using the six selected key indices, a multi-index comprehensive evaluation model based on CRITIC-TOPSIS is established to evaluate the two schemes. The evaluation results show that the northern priority development scheme is better than the pseudo-longitudinal mining scheme. Article Highlights The impact of steeper anticline on production of open-pit coal mine with nearly flat coal seam is analyzed, including: production quantity and quality of coal, release and utilization of internal dumping space, transportation distance and cost, etc. According to the geological features of the anticline region, solutions for the technical issues are proposed, such as coal exposure, working-line layout and development, internal dump construction and development, haulage system layout, and the selective mining of coal. Taking the Antaibao Open-pit Coal Mine as a case study, two mining and dumping engineering coordination development schemes are proposed. With the six selected key indices of the mining and dumping coordination development plans of the two proposed schemes during mining over the steeper anticline region, a multi-index comprehensive evaluation model of CRITIC-TOPSIS is established to evaluate the two proposed mining and dumping engineering coordination development schemes.