非对称外倾式钢箱拱桥扁平弯钢箱梁扭转与翘曲

以正在设计中的非对称外倾式钢箱拱肋扁平钢箱弯主梁结构形式的异型钢拱桥为背景，采用空间杆系模型对该桥进行恒栽和活栽作用下扁平钢箱主粱的扭转与翘曲受力特性分析；活载影响采用空间影响面方法计算，翘曲应力按乌曼斯基（Wumnansji）理论计算。计算结果表明，在恒载和活栽作用下，异形钢箱拱桥扁平钢弯箱梁的扭转剪应力可达到钢材容许剪应力的23．4％，在设计中必须加以考虑。

Torsion and Warping of Curved Flat Steel Box Girders for Steel Arch Bridge with Unsymmetrical Outward Inclined Ribs

The torsion and warping of curved clat steel box girders for steel arch bridge with unsymmetrical outward inclined ribs were discussed. The 3-D FEM and Wumnansji's principal were employed to analyze the torsion and warping caused by dead load and live load,and the influence surface was used in the analysis.The torsional shear stresses of the curved steel box girder under the considered loads may become 23.4 percent of the allowable shear stress of the steel,and it must be considered in the design of such bridges.