混合配筋预应力混凝土管桩抗弯承载性能研究#br#

通过开展6根混合配筋预应力混凝土管桩和3根预应力混凝土管桩的抗弯性能试验，分析非预应力钢筋的配置对混合配筋预应力混凝土管桩抗弯承载性能的影响。试验结果表明：配置非预应力钢筋可明显提高预应力混凝土管桩的抗弯承载力，对控制抗弯裂缝的开展有明显的效果。与试验数据相比，现有抗弯承载力公式的计算值合理有效，但公式形式较为复杂。针对混合配筋预应力混凝土管桩的抗弯承载力进行研究，将环形截面等效成工字形截面，并利用“等效钢带法”计算钢筋提供的轴力和弯矩，推导出了简化计算公式，其计算结果相对试验承载力具有合理的富余。相比原有公式，简化计算公式形式简单、易于计算，可应用于实际预应力混凝土管桩的设计分析中。

Study on flexural behavior of prestressed concrete pipe pile with hybrid reinforcement

Flexural tests on six prestressed concrete pipe piles with hybrid reinforcement (PRC pipe pile) and three prestressed high-strength concrete (PHC) pipe piles were carried out in this study. The effects of non-prestressed reinforcement on the flexural behavior of PRC pipe pile were investigated. It was revealed that the introduction of non-prestressed steel bars could significantly increase the flexural capacity and was remarkably beneficial to controlling  the propagation of flexural cracks. Compared to the test data, the calculated values from the existing formulas of flexural capacity, which are generally complicated, are reasonable and valid. To determine the flexural capacity of PRC pipe piles, the annular cross section was converted equivalently to I-shaped section, and the equivalent steel strip method was used to calculate the axial force and bending moment of the steel bar. Furthermore, a simplified formula for calculating flexural capacity of both PHC and PRC pipe piles was developed, and the calculated results based on the formula lead to reasonable agreements with the test results. Compared to the existing design formulas, the simplified formula is simple and convenient in calculation, and hence, it can be applied to the design of PHC and PRC pipe piles.