## 4 Case Study
### Technical Condition Assessment
#### 4.2.2 Calculation of Progressive Assessment  
The calculation of progressive assessment can be performed according to the deduct points gained above.  
1. Technical condition assessment of BECI members.  
* Members of side beam.  
According to Equation (1), the technical condition indices (keep two decimal place) of the left and right side beam are calculated as follows:  
\[N_{1}=\text{DP}_{\text{1-1-1}}=50\] \[N_{2}=\frac{\text{DP}_{\text{1-1-2}}}{100\times\sqrt{\epsilon}}( 100-\sum\limits_{r=1}^{\text{e}-1}N_{r})=\frac{25}{100\times\sqrt{2}}(100-\sum \limits_{r=1}^{1}N_{1})=8.84\] \[\text{MMCI}_{\text{1-1}}=100-\sum\limits_{e=1}^{2}N_{\epsilon}=1 00-(50+8.84)=41.16\] \[\text{MMCI}_{\text{1-2}}=\text{MMCI}_{\text{1-1}}=41.16\]
* Members of anchorage concrete.  
In the same way, the technical condition indices of the left and right anchorage concrete are obtained:  
\[N_{1}=\text{DP}_{\text{2-1-1}}=\text{DP}_{\text{2-2-1}}=100\] \[\text{MMCI}_{\text{2-1}}=\text{MMCI}_{\text{2-2}}=100-\sum \limits_{e=1}^{1}N_{e}=100-(100)=0\]
* Members of rubber sealing tape.  
There is only one member of rubber sealing tape in MA modular type BECI. Therefore, the technical condition index is calculated as follows:\[N_{1}=\text{DP}_{3-1-1}=50\] \[\text{AMCI}_{3-1}=100-\sum\limits_{e=1}^{1}N_{e} =100-(50)=50\]
2. Technical condition assessment of BECI components.
* Side beam. According to Table 8, the quantity of members of the side beam is two, which indicates the correction coefficient \(t\) is defined as 10. Under the guidance of Equation (2), the technical condition index of side beam can be calculated: \[\overline{\text{MMCI}_{1}}=(\text{MMCI}_{1-1}+\text{MMCI}_{1-2})/2=41.16\] \[\text{MCCI}_{1}=\overline{\text{MMCI}_{1}}-(100-\text{MMCI}_{1,\text{ min}})/t=41.16-(100-41.16)/10=35.28\]
* Anchorage concrete. In the same way, the technical condition index of anchorage concrete is acquired: \[\overline{\text{MMCI}_{2}}=(\text{MMCI}_{2-1}+\text{MMCI}_{2-2})/2=0\] \[\text{MCCI}_{2}=\overline{\text{MMCI}_{2}}-(100-\text{MMCI}_{2,\text{ min}})/t=0-(100-0)/10=-10<0\] \[\text{MCCI}_{2}=0\]
* Rubber sealing tape. Next comes the technical condition index of anchorage concrete: \[\overline{\text{AMCI}_{3}}=\text{AMCI}_{3}/1=50\] \[\text{ACCI}_{3}=\overline{\text{AMCI}_{3}}-(100-\text{AMCI}_{3,\text{ min}})/t=50-(100-50)/\infty=50\]
3. Technical condition assessment of BECI main structure and accessory structure. In accordance with Table 9, the calculation weights of side beam, anchorage concrete, and rubber sealing tape are gained, which are 0.75, 0.25, and 1, respectively. The technical condition indices of the main structure and accessory structure are calculated by Equation (3) as follows: \[\text{MSCI}=\sum\limits_{i=1}^{c}\text{MCCI}_{i}\times W_{i} =35.28\times 0.75+0\times 0.25=26.46\] \[\text{ASCI}=\sum\limits_{i=1}^{c}\text{ACCI}_{i}\times W_{i} =50\times 1=50\]
4. Technical condition assessment of overall BECI. Referring to Table 10 and the technical indices gained above, the technical condition index of overall BECI is acquired by Equation (4): \[\text{S}_{\text{I}}=\text{SMCI}\times W_{MS}+\text{SACI}\times W_{AS} =26.46\times 0.8+50\times 0.2=31.17\]