High-slope excavation in railway hub projects needs to achieve stable terrain reconstruction, defensible earthwork calculations, and visual coordination of design with construction. High-slope excavation on the south side of the Shenshan Station Hub Project was selected as the engineering case for this study to develop an integrated oblique-photogrammetry and BIM workflow. Low-altitude UAV oblique images were acquired with 80% forward overlap, 70% side overlap, a relative flight height of 150 m, a 1:500 mapping scale, and an approximate ground sampling distance of 3 cm. Aerotriangulation, dense matching, point-cloud cleaning, semantic segmentation, terrain-surface reconstruction, Civil 3D slope design, Dynamo-assisted quantity extraction and Revit-based model coordination were all performed on the image block. To strengthen the computational basis of the original study, this revision adds ground sampling distance, overlap-control, terrain-difference volume, cross-section volume, relative-deviation, vertical accuracy and progress-control formulas. As shown in the case comparison, the field-survey section method had an excavation volume of 193,899 m³, and the oblique-photogrammetry-BIM workflow had an excavation volume of 188,457 m³. The absolute difference is 5,442 m³ and the relative deviation is 2.81%; both are within the engineering control limit of 3%. The revised workflow now clarifies how the slope crest line, toe line, staged excavation surface and coordination model are derived from the same spatial data source. Based on the above research, it can be seen that the combination of oblique photogrammetry and BIM can improve the traceability of high-slope design, reduce manual interpretation in irregular terrain, and support visual construction briefings, quantity verification and risk-controlled excavation management.
