波形钢腹板组合槽形梁抗扭性能试验研究

为了研究新型结构预应力波形钢腹板组合槽形梁的抗扭性能，基于约束扭转理论，推导了波形钢腹板组合槽形梁的约束扭转翘曲应力表达式和扇形惯性矩；考虑了波形钢腹板的褶皱效应对纵向刚度的影响，计入波形钢腹板的剪切变形对约束扭转刚度的降低，得到了扇形惯性矩修正公式；最终建立了集中扭矩作用下的扭转角计算公式。完成了2片波形钢腹板组合槽形试验梁的偏载试验和3片相同梁的对称加载试验，试验表明：90 kN以内的偏载作用下，试验梁的荷载-位移曲线基本呈线性；试验梁两侧竖向位移的平均值与对称荷载作用下的竖向位移基本相同；试验梁的偏载系数位于1.2~1.3，比波形钢腹板组合箱梁增大10%左右。理论计算、试验测试和有限元分析表明：该文建立的扭转角计算公式采用修正过的扇形惯性矩进行计算，具有良好的精度。

EXPERIMENTAL STUDY ON TORSIONAL PROPERTY OF COMPOSITE TROUGH GIRDER WITH CORRUGATED STEEL WEBS

In order to study the torsional property of a new structure named prestressed composite trough girder with corrugated steel webs, the calculation expression of constrained torsional warping stress and the sectorial inertia moment of a composite trough girder with corrugated steel webs are deduced, based on constrained torsional theory for open thin-walled members. The accordion effect and the shear deformation of corrugated steel webs, which affects the longitudinal rigidity and weakens the constrained torsional stiffness respectively, are taken into account. Then a modified formula for the sectorial inertia moment is proposed, and a torsional angle formula under a concentrated torque is derived. 2 eccentric loading tests and 3 symmetrical loading tests of composite trough girders with corrugated steel webs were conducted. The test results indicate that the loading-displacement curves of test beams are linear when the eccentric loads are less than 90kN. The mean vertical displacements of test beams at the two sides are approximately the same with that of the test beams under symmetrical loading. The eccentric load coefficients of test beams are between 1.2 and 1.3, which are about 10% bigger than that of the box girder with corrugated steel webs. The theoretical calculation, experimental result, and finite element analysis indicate that the proposed torsional angle formula is rational when it used to calculate the re-corrected sectorial inertia moment.