考虑预应力筋增量的混凝土梁开裂弯矩计算公式研究

Study on Calculation Formula of Cracking Moment of Concrete Beam Considering Prestressed Reinforcement Increment

根据GB 50010—2010《混凝土结构设计规范》、JTG D62—2004《公路钢筋混凝土及预应力混凝土桥涵设计规范》和《混凝土结构基本原理》中对预应力梁开裂弯矩的分析,考虑梁体外加荷载引起的预应力细微变化,推导出一种先张法和后张法预应力混凝土梁开裂弯矩的计算公式。将按该计算公式得到的计算结果与规范计算结果进行对比,结果表明该公式更能反映梁体的实际受力变化。将试验数据与计算结果进行比较,结果表明两者符合程度良好,计算结果小于试验数据,结构偏于安全。

According to analysis to cracking moment of prestressed beam in GB 50010-2010 ＂Code for Design of Concrete Structures＂,JTG D62-2004 ＂Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts＂and ＂Basic Principles of Concrete Structures＂,considering minor variation of prestress caused by outer load of beam,this paper deduced a calculation formula of the cracking bending moment of advance post tensioned prestressed concrete beams. The results obtained by this formula are compared with the results of the calculation. The results show that the formula can better reflect the actual force change of the beam. Comparing the experimental data with the calculated results,the results show that the two tests are in good agreement with the experimental results with the calculated results smaller than that of the experimental data and the structure is safe.