연속압출공법 시공시 편심하중을 받는 PSC 박스 거더의 변형방지를 위한 보강 방법

In PSC box girder bridges built by incremental launching method(I.L.M.), distortion displacement and distortion stress, warping stress are insidious phenomenons that should be evaluated in design and prevented during construction. An eccentric load applied to the box girder produces bending and torsion, and it also produces distortion stress and warping stress. if warping deformation is restrained. Moreover, an eccentric load causes distortion, if the cross section of the beam is not rigid in its plane. In launched bridges, diaphragms are generally placed at the permanent support positions. But they cannot prevent distortion effectively during construction. Therefore, PSC box girder bridges by I.L.M subjected to eccentric load, require effectively and economically strengthening method. Using deformation minimization management curve by distortion displacement, we can decide zones of requiring reinforcement and reasonable intervals of stiffening member, so we can reduce distortion displacement and distortion stress, warping stress effectively. In order to acquire this curve, we suggest BEF analogy model that permits an analysis of this phenomenon and the optimization of the interaction between torsion and distortion. This results in a more agile and faster analysis than finite element analysis.