Issue 47

Y. Mizuno et alii, Frattura ed Integrità Strutturale, 47 (2019) 209-220; DOI: 10.3221/IGF-ESIS.47.16 214 A NALYSIS OF EXAMPLES Illustration method of transition of structure he four coloured shapes from the triangular coordinate system correspond to four types of life cycle states. Members in the construction, completed, retrofitted, and retrofitting states are shown in light blue, magenta, orange, and purple, respectively. The construction process proceeds from left to right. We examined six examples of construction processes illustrated below. Figure 7 : Construction states (G, S, T, A mean Girder, Suspension, Truss, Arch) . Single-operation Method of the Suspension Bridge (Fig. 8) This construction method involves an innovative idea in the construction process. When hung up, temporary compression diagonal members enable the structure to function as a cantilever truss balanced at both endpoints. After it is set, the cables, which are left at both the endpoints, are fixed at the anchor while the structure is hung up. As the temporary diagonal members are removed, the structural system becomes the suspension system. Thus, the structure supporting the dead load changes from the cantilever system to the suspension system. This bridge needs few temporary diagonal members to function as it is made of fibre reinforced plastic. Thus, this method is an example of a simple, single-operation method for small and medium sized bridges using only one crane. Furthermore, the design is innovative and aesthetic. This design hides the pylons in the trees and vegetation such that drivers under the bridge can see only the slender bridge girder. Figure 8 : Single-operation method of the suspension bridge (Halgavor Footbridge [6]). Construction of the Dischinger-Type Bridge (Fig. 9) At first, cable-stayed bridges are constructed to overhang from the pylons. The bridge is designed as a diagonal system, the truss system. Then, the pylons for making the cable-stayed bridge are used for the exact purpose as for suspension cables. T