# Optimization of Tunnel Construction Schedule Considering Soft Logic
## 5 Practical Case Study
### Results and Analysis  
As seen in Table 7, four optimization programs can be generated from the calculation, which are Optimization Program 1, with additional working surface switching points of 6-11-13-15, Optimization Program 2, with additional working surface switching points of 7-11-13-15, Optimization Program 3, with additional working surface switching points of 8-12-15, and Optimization Program 4, with additional working surface switching points of 8-13-15. The optimized durations of the programs are all 2387 days, which is a reduction of 646 days compared to the original duration. In the above-mentioned programs, the idle time of the construction teams was 741, 597, 502, and 459 days, respectively. It can be deduced that the construction team has the minimum waiting time in Optimization Program 4. However, the distance between the 13 th and 15 th additional working surface switching points is too short; therefore, Optimization Program 4 cannot fulfill the 500 m work continuity constraints. Thus, Optimization Program 3 can be regarded as the optimal tunnel construction schedule plan, in consideration of the duration, construction team idle time, and work continuity distance constraints.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Name**} & \multirow{2}{*}{**Tunnel Rock Mass Rating**} & \multicolumn{2}{c}{**Average Construction Speed**} \\  & & **(Meter/Month)** \\ \hline \multirow{3}{*}{Main tunnel} & III & 180 \\  & IV & 90 \\  & V & 50 \\ \hline \multirow{3}{*}{Parallel edit} & III & 190 \\  & IV & 130 \\  & V & 70 \\ \hline Cross passage & - & 33.3 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Speed of tunnel construction.  
Through the optimization program presented above, it can be seen that the final additional working surface switching points are all found at position 15, and the last construction activities are located on the working surface that opened in that position; hence, it can be concluded that the position of the final additional working surface switching point is critical to determine the duration. Furthermore, the gap between the construction speeds of the parallel adits and the main tunnel is not sufficiently large, leading to a long idle time for the construction team, which also seriously affects the duration. Therefore, the duration of the project can be shortened by speeding up the parallel adits in a way that creates more additional working surfaces.  
By utilizing the TSMOM model and its corresponding algorithms, the tunnel construction schedule can be optimized, leading to the formulation of practical strategies to effectively shorten the duration. Through the methods mentioned above, we can effectively address the limitations of various conditions, such as logical, work continuity, temporal, and spatial constraints, ensuring that the construction meets all relevant requirements. It can also better coordinate the allocation of labor, materials, and machinery resources to reduce idieness and construction stoppages, thereby improving efficiency. In addition, by formulating appropriate strategies tailored to the specific conditions of tunnel construction, it is possible to maximize the utilization of existing resources and mitigate resource wastage and redundant investment. Finally, optimizing tunnel construction scheduling through the above-mentioned methods can enhance the construction's resilience to uncertainties and improve its risk management capabilities, thereby reducing the likelihood of delays.