波形钢腹板PC组合箱梁纯扭作用下抗扭承载力试验研究

EXPERIMENTAL STUDY ON ULTIMATE TORSIONAL STRENGTH OF PC COMPOSITE BOX-GIRDER WITH CORRUGATED STEEL WEBS UNDER PURE TORSION

为了更好的了解波形钢腹板PC组合箱梁扭转力学机理及其抗扭承载力影响因素,该文通过模型试验的方法,对4根波形钢腹板PC组合箱梁模型进行纯扭作用下的承载力研究。通过偏心加载的方式对模型梁施加单调纯扭矩。试验结果表明:波形钢腹板PC组合箱梁在纯扭作用下,混凝土顶、底板裂缝方向与梁纵轴线基本成45°角;截面中心纵向钢筋对组合箱梁抗扭贡献不大;抗扭刚度与波形参数η成正比;钢腹板屈服扭矩与组合箱梁极限扭矩随着钢腹板厚度的增加而增大。

Abstract： To better understand the torsional mechanism and influencing factors of a PC composite box-girder with corrugated steel webs, the ultimate torsional strength of four scaled specimens under pure torsion was studied Monotonic pure torsion acts on specimens by eccentric concentrated loading. The experimental results show that cracks form at an angle of 45 to the member＇s longitudinal axis at the top and bottom of concrete slabs. Longitudinal reinforced steel bars located at the center of cross section contribute little to the torsional capacity of the specimens. The torsional stiffness is proportional to the corrugation parameter and there is an increase in yielding torque of steel webs and the ultimate torque of specimens increase as the thickness of corrugated steel webs.