## 3 Construction Risk Evaluation Index System of Deep Foundation Pit Projects
### Construction Risk Index System of Deep Foundation Pit Projects  
A literature review, expert interviews, and other methods were used to identify the secondary indices of the construction risk of deep foundation pit projects to create the WBS-RBS matrix. Twenty experts with engineering experience in related fields were invited to evaluate the secondary indices using a score of 0 or 1. Section 5 provides detailed information on the 20 experts. We used the construction risk source as the primary index and established the construction risk index system of the deep foundation pit project (Table 1). \(R_{14}\), \(R_{15}\), \(R_{22}\), \(R_{24}\), \(R_{31}\), \(R_{32}\), \(R_{41}\), \(R_{44}\), \(R_{51}\), and \(R_{52}\) are quantitative indices, whose scores were obtained using on-site statistics. The other indicators are qualitative indicators, whose index scores were obtained from the questionnaire survey. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Primary Index**} & \multirow{2}{*}{**Secondary Index**} & \multicolumn{5}{c}{**Risk Classification**} \\ \cline{3-6}  & & **I** & **II** & **III** & **IV** & **V** \\ \hline \multirow{4}{*}{\(R_{1}\): Man} & \(R_{11}\) : Risk awareness of managers & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{12}\): Rationality of risk management method & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\ \multirow{2}{*}{\(R_{1}\): Man} & \(R_{13}\) : Risk awareness of construction personnel & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{14}\) : Proportion of personnel with certificates for & (98,100) & (95,98) & (90,95) & (85,90) & (0,85) \\  & special operations (\%) & & (90,100) & (80,90) & (70,80) & (60,70) & (0,60) \\ \multirow{2}{*}{\(R_{15}\): Material} & \(R_{21}\) : Efficiency of material supply & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{22}\) : Concrete strength rating (\%) & (95,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{23}\) : Rationality of material price & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{24}\) : Welding steel strength rating (\%) & (95,100) & (90,95) & (85,90) & (80,85) & (0,80) \\ \multirow{2}{*}{\(R_{3}\): Machine} & \(R_{31}\) : Accuracy of mechanical installation (\%) & (95,100) & (90,95) & (85,90) & (80,85) & (0,80) \\  & \(R_{32}\) : Safety rate (\%) & (95,100) & (90,95) & (85,90) & (80,85) & (0,80) \\  & \(R_{33}\) : Maintenance conditions & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{34}\): Stability of power supply system & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{35}\) : Suitability of machinery operation & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\ \hline \multirow{4}{*}{\(R_{4}\): Method} & \(R_{41}\) : Rate of column verticality (\%) & (95,100) & (90,95) & (85,90) & (80,85) & (0,80) \\  & \(R_{42}\) : Accuracy of preliminary geological survey & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\ \multirow{2}{*}{\(R_{43}\): Method} & \(R_{43}\) : Suitability of detection method & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{44}\) : Safety rate of operation (\%) & (95,100) & (90,95) & (85,90) & (80,85) & (0,80) \\ \hline \multirow{4}{*}{\(R_{5}\): Environment} & \(R_{51}\) : Distance from underground pipeline (km) & (5,100) & (1,5) & (0.5,1) & (0.1,0.5) & (0,0.1) \\  & \(R_{52}\) : Distance from surrounding structures (km) & (5,100) & (1,5) & (0.5,1) & (0.1,0.5) & (0,0.1) \\ \multirow{2}{*}{\(R_{53}\): Hydrological conditions} & \(R_{53}\) : Hydrological conditions & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\ \multirow{2}{*}{\(R_{54}\): Geological conditions} & \(R_{54}\) : Geological conditions & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\  & \(R_{55}\) : Severe climatic conditions & (80,100) & (60,80) & (40,60) & (20,40) & (0,20) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Construction risk evaluation index system of deep foundation pit projects.