## 4 Computational Experiments
### Experimental Setting
The land use costs can  
Figure 1: The locations of construction waste facilities and construction sites in Guangzhou. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Recycling** & **The Maximum Area of the** & **Land Price** & **Land Cost** & **Total Cost** \\
**Center ID** & **Recycling Center (m2)** & **Class** & **(CNY/m2)** & **(CNY/m2)** \\ \hline HDZ5 & 4392.00 & 6 & 655 & 1415.58 \\ HDZ6 & 6665.00 & 5 & 975 & 1735.58 \\ HDZ7 & 3619.60 & 4 & 1317 & 2077.58 \\ BZ6 & 21,041.00 & 5 & 975 & 1735.58 \\ ZZ22 & 27,573.60 & 6 & 655 & 1415.58 \\ ZZ23 & 10,242.00 & 6 & 655 & 1415.58 \\ ZZ24 & 30,221.60 & 7 & 470 & 1230.58 \\ ZZ25 & 12,096.90 & 6 & 655 & 1415.58 \\ ZZ26 & 132,471.50 & 6 & 655 & 1415.58 \\ ZZ27 & 7925.50 & 7 & 470 & 1230.58 \\ \hline \hline \end{tabular} _Notes: (1) The column “land price class” refers to the eight categories of state-owned construction land prices determined by the Guangzhou Municipal Planning and Natural Resources Bureau based on the location of the land. Each category corresponds to a different price. (2) The figures in the column “Total costs” are calculated by summing the corresponding land cost and a construction cost of 760.58 CNV/m2._  
\end{table} 
Table 3: Basic information about recycling centers. be determined according to the geographical position of the potential recycling treatment plants. In terms of the fee for construction and equipment, a medium-scale recycling facility with a maximum waste recycling capacity of 200,000 tons per year requires EUR6,353,120 (about USD6,799,109) [56]. Given the average exchange rate of 1:7.6425 between the Euro and the Chinese Yuan in 2023 [57], the value of \(e^{2}\) is calculated by:  
\[\frac{653,120\times e^{1}}{200,000}=99.52\;\epsilon=760.58\;\text{CNY}.\]  
Following that, the two components of costs (land cost, construction cost, and equipment fee) are summed up to obtain \(C_{r}^{1}\), as shown in Table 3.  
Then, we introduce the data regarding the construction site. Here, the data related to parameters \(S\), \(S^{\prime}\), and \(V_{s,\omega}\) are introduced. Guangzhou comprises 11 municipal regions, such as Yuexiu District, Baiyun District, and Tianhe District. For simplicity, this study considers all construction sites within each municipal region as a single construction site positioned in the center of the municipal region, i.e., \(S=S^{\prime}=11\). This assumption possesses minimal impact on the optimal solutions, as the construction sites within an administrative district are generally close in proximity, thereby exerting little influence on transportation costs. For the generation of construction waste and the demand for recycled material, the Guangzhou Municipal Planning and Natural Resources Bureau has projected the average generation of construction and demolition waste for the next 15 years across 11 districts [51]. They have devised four methods for construction waste disposal, namely sorting center recycling, onsite soil backfilling within the urban area, comprehensive utilization, and direct landfilling, along with the anticipated quantities of construction waste to be disposed of for each method. Notably, the reuse process at the sorting center primarily involves manual filtration and shipment of valuable construction waste materials, such as paper, scrap, rebar, and formwork, to respective secondary markets [21]. Conversely, onsite soil backfilling refers to the transportation of excavated soil to low-lying areas for filling purposes. These two methods predominantly emphasize the reuse of construction waste, with limited involvement in recycling. Hence, this study regards the expected volume of construction waste to be processed through comprehensive utilization and direct landfilling as the actual generation of construction waste. The aforementioned amount of construction waste is to be handled jointly by ten potential recycling plants and existing disposal facilities in Guangzhou.