단순 I형 PSC 거더 교량의 매개변수 해석

Abstract

The PSC I-girder bridge is one of the most used bridges to build bridges with the span length of 25~40m. In designing, section forces are decided generally with live load distribution factors. The PSC I-girder bridges are built most, and standard sections are mostly used. Because of this design practice, designers are deciding factors according to individual's opinions or experiences without much paying attention to the accuracy and safety of distribution factors. Most of the bridges with small and medium span length are PSC I-girder bridges. The development of more accurate live load distribution factors is a must to meet economical efficiency and safety at the same time in the design field. The study began to develop new live load distribution factors. In order to develop live load distribution factors, we should choose the structure analysis model which represents structural properties of the given bridge. PSC I-girder bridge structure analysis model is compared, and the influence of diaphragms and barriers on the structure analysis model is analyzed. For comparing the structure analysis model, M2-peg is suitable in terms of the accuracy and efficiency of model analysis. For the influence of diaphragms and barriers, the M2-peg model was used by changing strength contribution of diaphragms and barriers 100%, 75%, 50%, 25%, and 0%. When strength is over 25%, diaphragms were less influenced by changes in strength. As for barriers, effects was small toe be neglected in structure analysis model. Among M2-peg models, when M2-peg-c(100%) and M2-peg-e(100%) were compared for diaphragms arrangement, M2-peg-c(100%) was safer than M2-peg-e(100%). Therefore, we can conclude that the M2-peg-c with 100% strength diaphragms is the most suitable for the structure analysis model for deciding live load distribution factors for PSC I-girder bridges. As the results of parametric analysis, live load distribution factors decreased as span length increased and they rose as girder distance and overhang length grew. The influential parameters on live load distribution factors are as follows in the most influential order: the girder distance, overhang, road width and span length.