No abstract

The first pedestrian cable stayed bridge using ultra-high performance concrete (UHPC) has been designed and constructed in Korea. The 200MPa class UHPC is the fruit of the research performed by the Korea Institute of Construction Technology (KICT). UHPC is an innovative and ultra-high strength material with compressive strength larger than 180MPa that has been developed to secure the ductility and strength of the structural members. UHPC exhibits significantly improved tensile, flexural and shear strengths enabling to minimize the crosssectional depth. However, the significant autogenous shrinkage developed by UHPC is also potentially favouring the occurrence of initial cracking in the case of structures presenting complicated shapes. Considering such characteristics of UHPC, a pedestrian cable stayed bridge using UHPC has been erected inside the site of KICT. The dynamic characteristics of the precast UHPC deck were evaluated through performance tests on the first UHPC pedestrian cable-stayed bridge. Examination of the maximum acceleration and displacement responses at the ends of the girder is carried out according to the excitation method. The estimated natural frequency, and measured vertical displacements and accelerations are compared with the design criteria. The corresponding results verify the applicability of UHPC not only to pedestrian cable stayed bridge but also to roadway cable stayed bridge.

The first pedestrian cable stayed bridge using ultra-high performance concrete (UHPC) has been designed and constructed in Korea. Our research team want to verify the practicability and feasibility of cable stayed UHPC highway bridges by means of the actual erection of a pedestrian cable stayed UHPC bridge as a test bed. According to the analysis and the preliminary vibration test of the pedestrian cable stayed UHPC bridge constructed, the results indicated that satisfactory serviceability in terms of vibration was secured for most of the pedestrian walking load cases. However, some responses exceeding the limiting criteria occurred in the case of impacts induced by the jumping of a pedestrian. Accordingly, TMDs (Tuned Mass Dampers) were installed on the parapet of the bridge in order to reduce vibrations. The TMD performance verification test showed that the maximum acceleration response of 0.186g, measured prior to the installation of the TMDs, reduced by more than 49% after the installation of the TMDs to reach a value of 0.095g, satisfying the limiting criteria of 0.1g in Korea.