波形钢腹板PC组合箱梁纯扭作用下抗扭承载力计算模型

Analytical model for torsional strength of prestressed concrete box-girder with corrugated steel webs

以扭转理论和固定角软化桁架模型为基础,推导了纯扭作用下波形钢腹板PC组合箱梁的抗扭承载力计算模型。该模型针对组合箱梁极限状态时,波形钢腹板处于屈服和未屈服状态两种情况,分别建立了剪应变连续与剪力流连续方程,模型同时考虑了不同位置预应力筋对抗扭承载力的不同作用。通过四根试验梁抗扭承载力理论计算结果与试验数据的对比分析,结果表明本文提出的计算模型不仅能够有效的计算抗扭承载力,还能计算出混凝土开裂后的扭矩—扭率曲线。

An analytical model for torsional strength of prestressed concrete box-girder with corrugated steel webs under pure torsion was deduced based on torsion theory and Fixed-Angle Softened Truss Model. Either the shear flow remains constant or the shear strain stays equal between the web and flange depends on the state of the corrugated steel web is in unyielding or yielding when the hybrid box-girder is in ultimate state. The effect of locations of prestressed tendons to torsional strength of the hybrid box- girder was also taken into consideration. The analytical model proposed in this paper was validated by four specimens subjected to cyclic pure torque. The results show that not only the torsional strength but also the torque-twist curve can he obtained through the analytical model developed in this paper.