# The Integration of Earthwork Design Review and Planning Using UAV-Based Point Cloud and BIM
## 4 Results
### Integrating Earthwork Design and Planning  
To establish an operational plan for the earthwork equipment based on the complementary design, the most commonly-used cell-based ground segmentation was carried out. To this end, the earthwork design function of Autodesk Civil 3D was used to generate a square cell of 3 m in size and calculate the volume between the original ground and the finishing ground, respectively, to fill and cut volume. Based on these calculations, this study determined that it would be correct to proceed with the earthwork in two stages. The first was to transport the soil on the north side to the finishing ground, and the second was to transport the soil piled up in the center to the junction area and the south side. Figure 6a shows the result of the earthwork construction plan of the Civil 3D, and it only shows the cut and fills the volume of each cell. Considering the design of the earthwork plan in a way that minimizes the overall earthwork balance and earthwork haulage distance, the yellow shaded cut-off zone (phase 1) shall be moved to the left and upper left, and the blue shaded cut-off zone (phase 2) shall be moved to the lower left as shown in Figure 5. Based on the general principle of the earthwork planning strategy, and in order to develop a more specific earthwork plan, this study generated cells spaced 3 m apart to further refine the area as shown in Figure 6b. The earthwork construction plan was set to move soil from A-zone to B-zone, and from C-zone to D-zone, respectively. The cut volume of the A-zone is 59.63 cubic meters, and upper part of the C-zone is 96.37 cubic meters, and the lower part of the C-zone is 279.97 cubic meters. Figure 4: The results of design review: (**a**) initial design; (**b**) revised design; (**c**) after construction (yellow: existing terrain, grey: building pad). Figure 5: Drainage flow of the site. After the BIM software generates the cut and fill grid map and division of phases, the basic work environment information (e.g., entrance, the shape of each phase, grid size, etc.) must be imported to the CCPP software for the operation level of earthwork plan (i.e., the equipment work sequence) The earthwork construction plan from Civil 3D can be exported as csv files and the data can be connected to the CCPP algorithm. As shown in Figure 8, the geometric shape of each phase was imported from BIM. Considering the amount of earthwork volume and the scheduled construction period, it was agreed that the earthworks only had to be completed within 14 days after discussing with an owner. In this study, a 5.9-ton excavator with a 0.18 cubic meter bucket was employed. Although the excavator is relatively small, the size of the site is small as well, so the excavator was able to work within two weeks with the sole operation of the excavator, and the actual construction period was 11 days. A dozen blade (2 by 0.338 m) was attached in front of the excavator so that excavated soil could be moved by using the blade. In order to perform the excavation and fill operations, it is necessary to generate a sequence of operations of excavators based on a 3 m cell that takes into account the separation of the work areas of the first and second stages and the working radius of the excavator. In this regard, we used the developed CCPP software [1] and generated a coverage path plan for zone C in phase 2. The CCPP software is able to produce near-optimal earthwork planning (i.e., travel sequences for an excavator) and is believed to be helpful when a single excavator is employed in a relatively small site. The coverage path plan was divided into two sections when the C zone was viewed as one and worked in two. The reason why zone C is divided into upper and lower sections is that the soil at the top may travel through zone A to the left of stage 1. In all cases, the starting point was to start at the lower right corner, where the amount of cutting was relatively high. When combined, as shown in Figure 8, we create a path to work by gradually moving the volume from right to left.