## 4 Results and Analysis
### Reliability Analysis Considering LLD Affected by Reinforcement Corrosion  
Based on the analysis of the vehicle load effect influenced by reinforcement corrosion, the reliability of the flexural bearing capacity was calculated according to the process shown in Figure 2. The reliability indexes of Beam 1 and Beam 2 were calculated as examples because the simply supported T-beam bridge in this paper is a five-beam symmetrical structure, and the beams close to the bridge edge bear a greater load effect. The reliability indexes shown in Figure 7 were calculated under the combination of LLD variation caused by reinforcement corrosion and inspection data updates. We present the following three cases: Case 1: The influence of reinforcement corrosion on LLD variation is not considered, and the model is not updated by the inspection data; Case 2: The influence of reinforcement corrosion on LLD variation is not considered, and the model is updated by the inspection data; Case 3: The influence of reinforcement corrosion on LLD variation is considered, and the model is updated by the inspection data. It can be seen from Figure 7 that the reliability indexes of Beam 1 and Beam 2 are the largest in Case 1 and the smallest in Case 3. The reliability obtained by the modified calculation method based on the comprehensive consideration of concrete strength and concrete cover thickness is lower, which indicates that the reliability results of the bridge bearing capacity obtained by the existing reinforcement corrosion calculation method are too conservative, and the modified calculation method based on Equation (5) in this paper can reduce this error. The influence of load effect on the reliability caused by reinforcement corrosion should not be ignored, either. In addition, the reliability index differences between the three cases are small. For Beam 1 and Beam 2, there is the same pattern, namely, the difference between Case 1 and Cases 2 or 3 is greater than that between Case 2 and Case 3. In this study, special attention is focused on reinforcement corrosion, which is one of the main influence factors for bridge degradation. In the early stage of structural degradation, the reduction of reinforcement capacity is so small that the reliability index difference is small. Figure 7: Influence analysis of LLD variation caused by reinforcement corrosion and inspection data updating on reliability. The probability distribution information of influencing factors as shown in Table 2, and the measured data processed by the Bayesian method without prior information as shown in Table 3 are taken as the input data of reliability analysis and compared with the time-dependent reliability results calculated according to the traditional LLD theory. Also taking Beam 1 and Beam 2 as examples, Figure 8 illustrates the time-dependent reliability index results calculated by the two methods. It turns out that the reliability indexes of Beam 1 and Beam 2 calculated by the traditional analysis method are larger than those calculated by the proposed method according to the time-dependent reliability curve of the flexural bearing capacity, and the reliability indexes calculated by the two methods have the same variation trend. The results indicate that the reliability evaluation method established in this paper can consider the influence of reinforcement corrosion on the bearing capacity of the T-beam and the vehicle load effect. This possible scenario enhances the accuracy of the reliability evaluation of the bridge, whereas the evaluation results obtained by the traditional method are too conservative. It is worth noting the variation tendency of the reliability index difference between the traditional method and the proposed method. In the early stage of reinforcement corrosion, the corrosion makes less contribution to bridge degradation. Therefore, the difference between the results of the two methods is small. With increasing service time, the difference becomes greater and greater.