混凝土刚架拱梁与索梁预应力计算方法分析

Analysis on calculation method of prestressed concrete rigid frame arch beam and cable beam

钢筋混凝土刚架拱梁与索梁结构由普通钢筋混凝土与预应力钢筋混凝土两种构件组成,将预应力作为等效荷载作用进行结构内力分析与构件截面设计时,需要计算主弯矩、次弯矩和综合弯矩。通过七个正截面内力计算简图推证:只需计算一个综合弯矩,再计入预压轴力对截面的作用,即可建立适合预应力复杂结构在承载能力极限状态下的截面计算公式,及正常使用极限状态下的钢筋应力增量计算公式。因预应力作用与外荷载对结构构件作用的方向相反,使构件控制截面上的内力绝对值变小,使结构可以承担更大荷载。

Reinforced concrete rigid frame arch beam and cable beam structure are composed of common reinforced concrete components and prestressed reinforced concrete components,and it needs to calculate the primary and secondary bending moments and comprehensive bending moment when prestress is taken as equivalent load action for structural internal force analysis and member cross-section design.The internal force calculation diagrams for seven cross-sections were derived to prove that it only needs to calculate a comprehensive bending moment combined with the effect of prestressed axial force on cross-section to establish calculation formula of cross-section for prestressed complex structure under the ultimate state of bearing capacity and establish calculation formula of steel bar stress increment under the ultimate state of serviceability.The structure can bear more loads because the action of prestressed force has the opposite direction to the external loading on the structural members to reduce the absolute value of the internal force on the control cross-section of the members.