## 4 Calculation Example
### Analysis Model
#### 4.2.3 Analysis of the Whole Construction Process  
The previous two parts focused on verifying the two core technologies in the non-bracket construction of an annular cable supported grid structure. In this part we carry out the simulation of the whole construction process of Education City Stadium according to the model and load conditions in Section 4.1 to track the deformation, stress, cable force, and other key technical indices of the structure at each stage of the assembly process, and then compare the results of construction forming state and dead load state. Table 18 lists the corresponding calculation conditions set according to the sequence of the whole construction process in Section 3. Especially, in step 5, the counterclockwise hoisting of the roof steel structure will be carried out gradually according to the section and direction in Figure 38.  
Analysis Results of the Whole Construction Process  
Figure 47 shows selected quarter CR node radial deformation under typical calculation conditions (C1 to C4 and C40 to C43), which indicates the following: \begin{table}
\begin{tabular}{c c c} \hline \hline
**Step** & **Calculation Condition** & **State** \\ \hline Step 1 & C1 & Install CR, structural columns, CR brackets, and additional cross-bracing between columns. \\ Step 2 & C2 & Pull and lift cable net. \\ Step 3 & C3 & Install and tension tie-downs to keep tension \\ Step 4 & C4 & Install cross-bracing between columns. \\  & & Hoist upper grid counterclockwise according \\ Step 5 & C5–C40 & to sequence in Figure 46, maintain design \\  & & tension ring configuration by adjusting \\  & & tie-down cable forces simultaneously. \\ Step 6 & C41 & Remove tie-downs. \\ Step 7 & C42 & Remove CR brackets and additional \\  & & cross-bracing between columns. \\ Step 8 & C43 & Install remaining roof components, and entire \\  & & structure is formed. \\ \hline \hline \end{tabular}
\end{table} 
Table 18: Calculation conditions during construction. Figure 46: Grid hoisting steps: (**a**) installation section diagram (blue and red indicate hoisting and closure units, respectively; E1, E2, E3,... E56 are codes of 56 units, marked according to specific assembly sequence; 1,15,29,43 represent the main axis. ); (**b**) installation sequence diagram. At the initial stage of structural construction (C1, C2), the internal forces of all cables are at a low level, which has little effect on radial CR deformation, and overall CR outward expansion deformation is large;  
From C3 to C40, the pre-tension of the cable net is gradually established, and the tie-downs start to control the tension ring at the design configuration during the construction process. Therefore, the cable forces in the cable net are large and stable, and the radial deformation values of the CR are relatively stable and close to 0, which means that the CR can basically remain in the design state configuration by adjusting the tie-down cable forces while the entire structure is not yet fully formed;  
From C41 to C42, the tie-downs are removed, and the CR radial deformation values increase again. Finally, in C43, the radial deformation values return to a level close to 0. Figures 48 and 49 present the radial and vertical deformation of selected quarter tension ring nodes (Tension ring clamps' nodes NO. are shown in Figure 50.) under typical calculation conditions (C1 to C4 and C40 to C43), which indicates the following:  
Figure 47: CR radial deformation curve (mm). Figure 48: Radial deformation curve of central nodes of tension ring clamps (mm). In the initial stage of structural construction (C1, C2), the traction lifting of the cable net makes the vertical and radial deformation of tension ring large;  
From C3 to 40, the deformation values are relatively stable and close to 0 because the tie-downs keep the tension ring at the design configuration during the whole upper grid installation process, ensuring stable and accurate grid installation;  
From C41 to 42, the tie-downs are removed, and the deformation values change again.