3.3.1. Selection of Parameters to Establish the Model

For the alignment analysis of large-span SCCB track cable-stayed bridges, it is necessary to select suitable random parameters and obtain the average value and coefficient of variation of these parameters. In this study, the random parameters and their statistical characteristics were selected considering the environmental factors, actual situation on the site, applicable standards and specifications, and other factors of the Nanjimen Yangtze River Track Special Bridge. The statistical characteristics of the random parameters are shown in Table 1, where X1 is the strength of the main beam, X2 is the mean annual humidity of the main beam environment, X3 is the concrete age at the beginning of main beam shrinkage, X4 is the strength of the main tower, X5 is the mean annual humidity of the main tower environment, X6 is the concrete age at the beginning of the main tower shrinkage, X7 is the volume weight of the main beam, and X8 is the volume weight of the main tower.


**Table 1.** Statistical characteristics of random parameters.

3.3.2. Selection of Samples to Establish the Model

To study the long-term deformation of the entire bridge, six different time nodes were selected for analysis, namely, 1/2 year, 1 year, 2 years, 3 years, 5 years, and 10 years since the bridge completion. The vertical deformation of the mid-span position of the main span for these time nodes was studied. The structural influence values were denoted as S1/2, S1, S2, S3, S5, and S10, respectively, and the uniformity experiment was carried out according to the uniform design table of U8(88). Eight sample points were obtained by testing each set of data, with the deformation of the main beam defined as negative when vertically downward and positive when vertically upward. In this way, the sample points of the uniform design (Table 2) and the structural response data were obtained (Table 3).

**Table 2.** Sample points based on uniform design.


**Table 3.** Structural response data (mm).

