*3.1. Project Profile*

The Nanjimen Yangtze River Track Special Bridge connects Yuzhong District and Nan'an District and is an important link in the second phase project of Chongqing Rail Transit Line 10. The main bridge is a five-span double-cable plane and high-low tower cable-stayed bridge with a semi-floating system. The span arrangement of the main bridge is 34.5 + 180.5 + 480 + 215.5 + 94.5 m. The main girder is a SCCB, and the portal tower form is used. The bridge type layout, cross-section view of the main beam, the main tower, and the cable are shown in Figures 1–4, respectively.

**Figure 1.** The bridge type layout of Nanjimen Yangtze River Track Special Bridge (unit: mm).

**Figure 2.** Cross-sectional view of the main beam (unit: mm).

**Figure 3.** Cross-sectional view of the main tower (unit: mm).

**Figure 4.** Cross-sectional view of the cable.

## *3.2. Finite Element Analysis*

MIDAS/Civil was used to carry out the FE numerical analysis model of the Nanjimen Yangtze River Track Special Bridge (Figure 5). The model used beam elements to simulate the main tower, pier, and main beam, and truss elements to simulate the cables. The boundary conditions of the model included complete consolidation between the main tower and the pier, a rigid connection between the main tower and the stay cable, and tri-directional restraint at the boundary of the auxiliary pier. In this model, the shrinkage and creep of concrete were considered, and the material properties given in the design drawings were used. At the same time, according to the "Code for Design of Railway Bridges and culverts" (TB10002-2017) issued by the National Railway Administration, the time-dependent characteristics were considered, and the software was used to automatically calculate the most adverse effects of shrinkage and creep loads.

**Figure 5.** The FEM numerical analysis model of the Nanjimen Yangtze River Track Special Bridge.
