# A New Method for Haul Road Design in Open-Pit Mines to Support Efficient Truck Haulage Operations
## 4 Case Study
### Three-Dimensional Modeling and Visualization of Road Design Result  
In this study, a 3D haul road was designed using the AutoCAD Civil 3D software of Autodesk. The 3D haul road was designed by using the 3D mine terrain formed in Section 4.1 and the 2D haul road layout analyzed in Section 4.2 as the input for the software. Figure 16 shows the terrain profile (solid line), showing the altitude of the haul road and the vertical alignment design result (dashed line) of the haul road. The vertical alignment of the haul road was designed in such a manner that the surrounding terrain would not be cut artificially. In other words, it was designed to fill in a new terrain for the difference in altitude between the haul road and the surrounding terrain. Considering that this is a small mine, one lane was assumed and the width of the small haulage equipment was assumed as 4 m. The width of the haul road was calculated as 8 m using Equation (4). The fill slope was designed to be identical to the bench surface slope. Figure 14: Simplification of haul road layout of Pit 1 and Pit 2. The paths connect the loading point in Pit 1 with (**a**) the stockpile and (**b**) the waste dump and the loading point in Pit 2 with (**c**) the stockpile and (**d**) the waste dump. Figure 15: Results of modifying the road layout in Pit 1 and Pit 2 by considering the radius of curvature. The paths connect the loading point in Pit 1 with (**a**) the stockpile and (**b**) the waste dump and the loading point in Pit 2 with (**c**) the stockpile and (**d**) the waste dump. Figure 17 shows the design result of the haul road of the open-pit mine and its 3D visualization that was obtained by combining the mine terrain model designed with benches and the result of the 3D haul road layout design. The interconnection between the lower and upper benches enables the smooth operation of haulage equipment. The lower terrain of the haul road was filled for the difference in altitude with the surrounding terrain to form a new terrain. In this study, the haul road layout was re-analyzed by using LCPA to obtain a topographic model of an open-pit mine designed with a haul road. For the analysis, the 3D mine terrain designed with a haul road was converted to a DEM consisting of 5 m \(\times\) 5 m grids. The departure point of the truck was set as the work site at the bottom of Pit 1, and the destinations of the truck were set as the respective  
Figure 16: Results of analyzing the terrain profile (solid line) and designing the vertical layout (dashed line) of the haul road in (**a**) Pit 1 and (**b**) Pit 2. Figure 17: (**a**) Open-pit mine with bench and haul road. 3D views: (**b**) Pit 2 area, (**c**) Pit 1 area. entrances to the stockpile and the waste dump. Furthermore, the terrain slope of every cell comprising the DEM was calculated, and the cost map was created by assigning the travel time per unit distance of the truck to each cell according to the terrain slope. The vertical and horizontal factor models are shown in Figure 12.  
Figure 18 shows the haul road layout analyzed through LCPA based on the 3D mine terrain model in Figure 17. The layout of this haul road has an almost identical path to the haul road layout in Figure 15. The approximate one-way travel time, travel distance, and speed of the truck could be estimated additionally by analyzing the haul road layout (Table 4). The travel time and distance calculated for the truck were higher and the travel speed of the truck was lower on the upward slope compared to the downward slope. The approximate haulage operation time in an actual mine can be estimated by using the one-way operation time data of the truck. Furthermore, our method enables a haulage operation plan in an open-pit mine to be established because the type, number, and combination of haulage equipment required in haulage operations can be determined. according to the radius of the curvature constraint presented in existing guides.