• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.2
• /
• pp.1-7
• /
• 2021

The concrete deck slab at the continuous span support of the steel box girder bridge is a structure that is combined with the upper flange. It is a structure that can cause tension cracks in the deck slab at the support causing problems such as durability degradation in long span bridges. This is because the tensile stress in the longitudinal direction of the slab exceeds the design tensile strength due to the effects of dead load and live load when applying a long span. Accordingly, it is necessary to control tensile cracking by adding a reinforcing bar in the axial direction to the slab at the support and to introduce additional compressive stress. To solve this problem, a structural system of a steel box girder bridge was proposed that introduces compressive stress as PS steel wire tension in the tensile stress section of the upper slab in the continuous support. The resulting structural performance was compared and verified through the finite element analysis and the steel wire tension test of the actual specimen. By introducing compressive stress that can control the tensile stress and cracking of the slab generated in the negative moment through the tension of the PS steel wire, it is possible to improve structural safety and strengthen durability compared to the existing steel box girder bridge.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.3
• /
• pp.323-331
• /
• 2022

An experimental study was conducted to investigate the effect of applied tensile force and temperature on the permeability of magnetic flux in prestressing steel. The permeability of magnetic flux is the ratio at which the magnetic flux between two points passes. The prestressing steel used in these experiments included a 7-mm PS wire mainly used for cable-stayed bridges and a 12.7-mm PS strand for prestressed concrete bridges. The experiments to extract the permeability of the magnetic flux of steel wire and strand were conducted under various tensile levels and temperature conditions. From the experimental results, it was observed that the permeability of magnetic flux of the PS tension material was linearly proportional to the applied tensile stress level, and inversely proportional to the temperature. If the experimental relationship among the magnetic permeability, temperature, and prestressing ratio of a PS tension material is known in advance, the current tension stress level on PS members can be evaluated by measuring solely the magnetic permeability and temperature.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.3
• /
• pp.555-561
• /
• 2024

This paper derives material properties of steel bars that simulate the distribution of stress and strain of prestressed tendons used in Prestressed concrete(PSC) girders and presents an optimal material model. ABAQUS software was used to establish the 3D solid model of the PSC girder and strand wire rope for a PS(Prestressed) tendon. Then the model of steel wire rope was imported into the Isight interface plugin directly through the ABAQUS and the Data Matching. In ABAQUS, the contact pairs were established, the models were meshed, the constraints were applied to solve the finite element model and an axial tension of 0.5m/s was loaded to analyze the stress and deformation distributions in the normal working range of the PS strand wire rope. In Data Matching, classical experimental data is fitted to the optimal material properties through finite element analysis and multi-objective optimization. The results show that the steel bar with optimal material properties presents a similar linear area and stress distribution with the PS tendon.