Issue 47

Y. Mizuno et alii, Frattura ed Integrità Strutturale, 47 (2019) 209-220; DOI: 10.3221/IGF-ESIS.47.16 217 post. Therefore, the span, which includes the repair part, is regarded as two cantilever girders butted against each other. Thus, the final structure system is a retrofitted cantilever girder with the spanning system. Figure 13: Reinforcement by retrofitting the middle hinge of a PC bridge with string beam structure (Kireuriwari Bridge [10]) . E VALUATION OF THE APPLICABILITY AND EFFICIENCY OF STRUCTURAL SYSTEMS he lifecycle of brides involve many construction types, including new construction, reinforcement, repair, and removal. New construction is a basic construction type used to consider all other types. Structural changes that occur in new constructions are shown in Tab. 4 and Tab. 5. (Note: Tab. 4 and Tab. 5 are presented separately to avoid spacing issues). We analysed the “Applicability of Structural System”, which indicates the likelihood that a structural system will change to another system and “Efficiency of Material and Time” for Tab. 4 and Tab. 5. Applicability of Structural System The vertical cable erection method, which uses a suspension system, can be used to construct almost all types of bridges. The diagonal cable erection method or overhanging erection method, which use a diagonal system, can be applied to many types of bridges, such as arch bridges, cable-stayed bridges, and truss bridges. Using the special construction methods of the “Halgavor Footbridge” suspension bridges can also be constructed with a diagonal system. In this respect, a suspension system and a diagonal system have high potential for constructing various types of bridges. On the other hand, while a web system can be used in the launching method as a beam system, the applicability of that structural system is comparatively low. An arch system is rarely used in the construction state. However, the applicability of a suspension system and a diagonal system in the construction state is particularly high. Material Efficiency Bridges that do not undergo changes in their structural system from the construction to the completed state throughout the cycle, such as a suspension bridge or a cable-stayed bridge, have high material efficiency because they do not require massive temporary structures. Time Efficiency Bridges using a beam system have high time efficiency because they can be placed using parallel translation such as the launching-type erection method. In addition, a beam system can be hung up by a small number of cranes. However, these methods generally require many temporary structures in the construction state. Accordingly, material efficiency tends to be low. Nevertheless, attempts can be made to improve material efficiency by using temporary structures several times. T