## 2 Engineering Background and Calculation Model Establishment
### Calculation and Analysis Model  
This bridge is analyzed using the bridge finite element analysis software Midas Civil V2019. The overall model of the cable-stayed bridge adopts a fishbone model, with beam elements used for the pier columns, and bridge towers, main beams. Truss elements used for the stay cables as shown in Figure 5. In the calculation, construction processes such  
\begin{table}
\begin{tabular}{c c} \hline
**Term** & **Detail** \\ \hline Phase II dead load & Asphalt concrete pavement + sidewalk slab + sidewalk guardrail + central median strip guardrail + wind nozzle \\ \hline Cable tower & Double column variable cross-section curved concrete tower, 125 m height; C55 \\ \hline Foundation & Group pile foundation; C35 \\ \hline Original construction methods & Main beam, bridge deck, and phase II dead load are all under full hall support. \\ \hline \end{tabular}
\end{table}
Table 1: _Cont._  
Figure 4: Original design and construction process.  
as foundation construction, bridge tower construction, main beam erection, lower cable tensioning, and bridge deck slabbing are considered. The main beam section adopts a steel-concrete construction stage joint section, and the UHPC part of the joint section is activated one by one according to the construction sequence to participate in the structural internal stress.  
The unit weight of steel is taken as 78.5 kN/m\({}^{3}\); the gravity density of UHPC is taken as 28.0 kN/m\({}^{3}\). C55 concrete is taken as 26.0 kN/m\({}^{3}\). The second-phase dead load is taken at approximately 73.0 kN/m.  
The UHPC detailed parameters are shown in Table 2.  
The initial tension cable force is shown in Table 3.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Elastic Modulus** & **Poisson’s Ratio** & **Uniaxial Tensile Strength** & **Uniaxial Compressive Strength** \\ \(E_{0}\) (N/mm\({}^{2}\)) & \(\
u\) & \(f_{t}\) (N/mm\({}^{2}\)) & \(f_{c}\) (N/mm\({}^{2}\)) \\ \hline
37,600 & 0.2 & 22 & 77.4 \\ \hline \end{tabular}
\end{table}
Table 2: UHPC parameters.  
Figure 5: Overall calculation and analysis model.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Cable** & **Cable Type** & \multicolumn{2}{c}{**Initial Tension Force (kN)**} & \multirow{2}{*}{**Position (m)**} \\ \cline{2-3}
**No.** & & & **AVG** & \\ \hline S21 & PES(C)7-151 & 2987.5 & 198 \\ \hline S20 & PES(C)7-151 & 2851.3 & 189 \\ \hline S19 & PES(C)7-139 & 2504.4 & 180 \\ \hline S18 & PES(C)7-121 & 2289.7 & 171 \\ \hline S17 & PES(C)7-121 & 2225.7 & 162 \\ \hline S16 & PES(C)7-121 & 2196.4 & 153 \\ \hline S15 & PES(C)7-139 & 2551.7 & 144 \\ \hline S14 & PES(C)7-139 & 2526.3 & 135 \\ \hline S13 & PES(C)7-151 & 2578.6 & 126 \\ \hline S12 & PES(C)7-151 & 2647.5 & 117 \\ \hline S11 & PES(C)7-151 & 2460.1 & 108 \\ \hline S10 & PES(C)7-139 & 2311.1 & 99 \\ \hline S9 & PES(C)7-139 & 2242.7 & 90 \\ \hline S8 & PES(C)7-139 & 2273.1 & 81 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Specification and force of stay cables.  
In terms of the content of the comparative analysis of pouring plans, the procedure was is as follows: (1) during the construction phase, the primary consideration is the impact of the post-pouring concrete (UHPC) on the already poured concrete (UHPC), including additional deformation and tensile stress of the formed UHPC bridge decks; (2) during the completion stage, the primary considerations include the bridge shape, cable force uniformity, UHPC bridge deck tensile stress, and steel box girder stress. The benchmark model for comparative analysis is the original design pouring plan (full support pouring plan).