PSC박스거더교 상부슬래브에서의 시간의존적 변형률 분포

Distribution of Time-dependent Strains In the Top Slab of PSC Box Girder Bridge

PSC(Prestressed Concrete) box girder bridges have been widely applied in Korea. A number of these bridges have been built by the segmental construction method in the longitudinal direction and(or) vertically along the cross-sectional depth with MSS(Moving Scaffolding System). An actual 2-span continuous PSC box girder bridge of Kyeongbu high speed railway was selected and instrumented with 96 vibrating wire embedded type strain gauges and 2 thermocouples. The long-term behavior of the bridge was monitored through two major points located at mid-span of the first span and at the internal support. Data collection started just after the casting of the first segment (U section). Concrete strain and temperature data were gathered regularly by a data logger (CR10) during 600 days under and after construction. According to this measurement, the parabolic longitudinal strain distribution in the top slab at mid-span is shown. And also, the same distribution at the interior support is shown. The compressive strains at the cantilever region are larger than at the web position and the internal part in the top slab. Strain difference largely happened during the early construction period.