## 3 Methodology
### Technical Condition Assessment
#### 3.1.3 Calculation of Progressive Assessment
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Inspection Object** & **Inspection Index** & **Scale** & **Qualitative Description** & **Quantitative Description** \\ \hline \multirow{3}{*}{\begin{tabular}{c} Fixed comb plate, \\ movable comb plate \\ \end{tabular} } & \multirow{3}{*}{Evenness} & 2 & \multirow{3}{*}{Slightly uneven, local fractures occur} & Damaged area \(\leq\) 10\%, 1 mm \(<\) \\  & & & & elevation differences \(\leq\) 2 mm \\  & & & & elevation differences \(\leq\) 30\%, 2 mm \(<\) \\  & & & & 10\% \(<\) damaged area \(\leq\) 30\%, 2 mm \(<\) \\  & & & & elevation differences \(\leq\) 4 mm \\  & & & & 10\% \(<\) damaged area \(>\) 30\%, 2 mm \(<\) \\  & & & & elevation differences \(\leq\) 4 mm \\  & & & & 10\% \(<\) damaged area \(>\) 30\% \\ \hline \multirow{3}{*}{\begin{tabular}{c} Anchor bolt \\ \end{tabular} } & \multirow{3}{*}{Elevability} & 2 & \multirow{3}{*}{Local abrasions occur} & Damaged area \(\leq\) 10\% total area \\  & & 3 & Multiple abrasions occur & 10\% \(<\) abrasion area \(\leq\) 30\% total area \\  & & & 4 & Massive abrass occur & Abrasion area \(>\) 30\% total area \\ \hline \multirow{3}{*}{\begin{tabular}{c} Multidirectional \\ displacement device \\ \end{tabular} } & \multirow{3}{*}{Eleviness} & 2 & \multirow{3}{*}{Local anchor bolts are unfixed} & Proportion of damaged bolts \(\leq\) 10\% \\  & & & & 10\% \(<\) proportion of damaged bolts \(\leq\) \\  & & & & 30\% \\  & & & 4 & Massive anchor bolts are unfixed & Proportion of damaged bolts \(>\) 30\% \\ \hline \multirow{3}{*}{\begin{tabular}{c} Anchorage concrete \\ \end{tabular} } & \multirow{3}{*}{Fracture} & 2 & \multirow{3}{*}{Individual unit is inflexible} & 1 inflexible unit \\  & & 3 & Partial units are inflexible & 2 inflexible units \\  & & & Multiple units are inflexible, device & Inflexible units \(>\) 2 \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} Anchorage concrete \\ \end{tabular} } & \multirow{3}{*}{Fracture} & 2 & \multirow{3}{*}{Local fractures occur} & Fractures \(\leq\) 3, fracture width \(\leq\) 2 mm, \\  & & & & damaged area \(\leq\) 10\% anchorage \\  & & & & 3 \(<\) fractures \(\leq\) 5, 2 mm \(<\) fracture \\  & & & width \(\leq\) 10 mm, 10\% anchorage \\  & & & concrete area \(<\) damaged area \(\leq\) 20\% \\  & & & anchorage concrete area \\  & & & & Anchorage concrete area \\  & & & & \\  & & & & fractures \(>\) 5, fracture width \(>\) 10 mm, \\  & & & & damaged area \(>\) 20\% anchorage \\  & & & fails & concrete area \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Drainage device \\ \end{tabular} } & \multirow{3}{*}{Fracture} & 2 & \multirow{3}{*}{Local fractures occur} & Fractures \(\leq\) 3, damaged area \(\leq\) 10\% \\  & & & & total area \\  & Fracture & 3 & Multiple fractures occur & 3 \(<\) fractures \(\leq\) 5, 10\% \(<\) damaged area \\  & & & & \(\leq\) 30\% total area \\  & & & 4 & Serious fractures occur & Fractures \(>\) 5, damaged area \(>\) 30\% \\  & & & total area \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Inspection index evaluation of the BECI of SSA, SSB comb plate type. 1. Technical condition assessment of BECI members The technical condition assessment of BECI members is calculated as follows: \[ \begin{split}\text{MMCI}_{i-l}(\text{AMCI}_{i-l})=100-\sum\limits_{x =1}^{k}N_{x}\\ N_{e}&=\text{DP}_{i-l-j,\;\;\;e}=1\\ N_{e}&=\frac{\text{DP}_{i-l-j}}{100\times\sqrt{e}}(100- \sum\limits_{r=1}^{e-1}N_{r})(\text{where}\;j=e),\;e\geq 2\end{split} \] (1) where MMCI and AMCI are the condition indices of members, which belong to the main structure and accessory structure, respectively; \(i\), \(l\), and \(j\) denote component \(i\), member \(l\), and inspection index \(j\); \(k\) is the quantity of inspection indices; \(x\), \(e\), and \(r\) are introduced variables; DP is the deduct point, which is determined by the technical condition scales of each inspection index according to Table 7.
2. Technical condition assessment of BECI components The technical condition assessment of BECI components is calculated as follows: \[