Recently, concrete-steel hybrid girder is being developed to improve economic efficiency and durability. To evaluate flexural behavior of the proposed girders, 17.0m full-scale joint was fabricated and tested under vertical loading. The study was examined vertical displacement; the strain of the reinforcement; and the crack patterns in the concrete. The proposed girders was analyzed to be safe in all members.

In this paper, to overcome disadvantages of existing lining boards, the parametric studies to evaluate safety and verify performance of newly suggested lining boards was performed. Since the calculated stresses of steel plates are lower than the allowable stress for considered all analytical variables, end reinforcement locations, and crane rail loads, it can be concluded that the suggested lining board is structurally safe. Where, “3,000×2,000×6t” was select to be optimized cross-section and the reinforcement from the end to 200mm to the internal direction looks like the best case. In addition, the suggested lining board is economical since the steel amount per unit area compared to existing lining board is reduced by 36% and it can apply to the lining structural system of subway and underpass since construction speed is past due to the less installation number of lining boards.