无黏结预应力连续梁次弯矩演化及弯矩调幅

发布时间：2018-05-01 23:31

  本文选题：预应力连续梁 + 无黏结筋　； 参考：《同济大学学报(自然科学版)》2014年12期

【摘要】：完成4根无黏结预应力混凝土两跨连续梁受力全过程试验,对支座反力及控制截面弯矩重分布程度进行分析.运用非线性阶段的预应力次弯矩定义,将非线性阶段连续梁总弯矩分解成次弯矩和荷载弯矩.研究加载全过程次弯矩和荷载弯矩的演化规律,提出了对初始次弯矩和弹性荷载弯矩分别调幅的无黏结预应力混凝土连续梁弯矩调幅公式.采用已有文献中一组试验梁对所提公式的计算精度进行验证.研究结果表明,无黏结预应力连续梁弯矩重分布的原因可以归结为无黏结筋应力的增长以及连续梁各部分割线刚度比值的改变.承载力极限状态下,次弯矩折减系数随中支座综合配筋指数的增大而增大,荷载弯矩调幅系数随其增大而降低.文中弯矩调幅建议公式较已有公式更接近试验结果,可为设计规范中相关条款的制订提供参考.
[Abstract]:Four unbonded prestressed concrete two-span continuous beams were tested during the whole process of loading, and the reaction force of the bearing and the distribution degree of the controlled cross-section moment were analyzed. By using the definition of pre-stress secondary moment in nonlinear stage, the total moment of nonlinear continuous beam is decomposed into secondary moment and load moment. The evolution law of secondary moment and load moment in the whole process of loading is studied. The formula of moment modulation of unbonded prestressed concrete continuous beam is presented, which is used to adjust the amplitude of initial secondary moment and elastic load moment respectively. The calculation accuracy of the proposed formula is verified by a group of experimental beams in the literature. The results show that the redistribution of bending moment of unbonded prestressed continuous beams can be attributed to the increase of the stress of unbonded tendons and the change of the ratio of Secant stiffness of each part of continuous beams. In the ultimate state of bearing capacity, the secondary moment reduction coefficient increases with the increase of the composite reinforcement index of the middle support, and the amplitude modulation coefficient of the load moment decreases with the increase of the composite reinforcement index of the middle support. The suggested formula of bending moment amplitude modulation is closer to the test result than the existing formula, which can be used as a reference for the formulation of relevant clauses in the design code.
【作者单位】： 同济大学土木工程学院;
【分类号】：TU378.2
，

本文编号：1831464