# Influence Line-Based Design of Scissors-Type Bridge
## 5 Conclusions  
This study investigated the I.L. diagrams of axial forces, bending moments, and shear forces on the structure of DWT and CSCI models. The concept involves moving live loads along the structure using truck model H-25 (22,675 kgf). The maximum axial force, shear force, and bending moment were obtained. To summarize, we can conclude the following:  
1. Using the equilibrium mechanics theory of the SCI, we obtained the equations of the primary I.L.s of the sectional forces of the frame elements with pin-connections. Furthermore, their I.L. has been used to design the maximum loading point of a structure by the equilibrium equations and the assumed loading from the small SCI to the main SCI.
2. The authors numerically analyzed the CSCI structure, resulting in a normal SCI structure that is used currently.
3. The I.L. at which the axial force \(N\) is higher than \(P=1\) unit at 2 nd, 3 rd, 4 th nodal points, is 1.1 unit (+10%); Shear force \(Q\) is lower than \(P=1\) unit at 3 rd nodal point, the I.L. is 0.7 unit (\(-30\%\)); Bending moment \(M\) is higher than \(P=1\) unit at 3 rd nodal point, the I.L is 2.2 unit (+120%).
4. A comparison between the stress of DWT and CSCI structure showed that the stress of CSCI (A) is greater than DWT by 10%, while the stress of CSCI (B) is lower than DWT by 2%, but displacement is only over 10%. Moreover, in the case where the comparative model is CSCI (A), we can observe that the CSCI (B) clearly shows potential that when upper reinforcement member is applied, the stress reduces by 11%, while the mass increases by only 8%.  
The results in this paper showed that if we develop CSCI (B) as an emergency bridge, it will be more significant than other models because of its deployment mechanism and efficiency. However, it is still difficult to deploy CSCI (D). CSCI (D) can be used for other applications in coupling scissor-type devices in the future.  
\begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline
**Model** & **Mass** & **Disp.** & **VMS** & **1 st PS** & **3 rd PS** & **Mass** & **Disp.** & **VMS** \\
**Names** & **kgf** & **mm** & **MPa** & **MPa** & **MPa** & **Ratio** & **Ratio** & **Ratio** \\ \hline DWT & 999.15 & 7.52 & 104.96 & 103.13 & 12.61 & 1.00 & 1.00 & 1.00 \\ CSCI (A) & 1027.46 & 9.15 & 114.98 & 114.01 & 25.67 & 1.03 (1.00) & 1.22 (1.00) & 1.10 (1.00) \\ CSCI (B) & 1111.48 & 8.22 & 102.49 & 104.81 & 32.47 & 1.11 (1.08) & 1.09 (0.89) & 0.98 (0.89) \\ CSCI (C) & 1195.5 & 6.53 & 102.49 & 105.45 & 28.80 & 1.20 (1.16) & 0.86 (0.71) & 0.98 (0.89) \\ CSCI (D) & 1277.83 & 5.75 & 83.79 & 85.63 & 25.72 & 1.28 (1.24) & 0.76 (0.63) & 0.80 (0.73) \\ \hline \hline \end{tabular}
\end{table}
Table 1: The simulation results of DWT & CSCI models A, B, C, D by Autodesk Inventor 2018.  
Figure 15: The simulation results of CSCI models. (**a**) CSCI model-A. (**b**) CSCI model-B. (**c**) CSCI model-C. (**d**) CSCI model-D.  
**Author Contributions:** Conceptualization, I.A. and Y.C.; methodology, Y.H. and I.A.; software, Y.H. and K.C.; validation, Y.C. and I.A., formal analysis, Y.H. and K.C.; investigation, Y.H. and K.C.; resources, Y.H. and I.A.; data curation, Y.C.; writing--original draft preparation, Y.H. and K.C.; writing--review and editing, K.C. and H.M.; visualization, K.C. and Y.H.; supervision, I.A.; funding acquisition, A.F. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by Japan Society for the Promotion of Science grant number 19H00784.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request. All data, models, and code generated or used during the study appear in the submitted article.  
**Conflicts of Interest:** The authors declare no conflict of interest.