| 摘要: |
| 为了对预应力加固老化病害混凝土的修复效果进行评价，研究了预应力施加于连续组合梁的负弯矩区的抗弯性能，完成了4根预应力组合梁在反向跨中集中加载下的静载试验。探讨了不同剪力连接程度对预应力组合梁受力性能的影响，分析了梁的荷载-跨中挠度特征，同时建立了弹性和极限承载能力计算式。研究结果表明，完全剪力连接的组合梁的抗弯刚度和承载力大于部分剪力连接组合梁，但刚度和承载力与剪力连接程度并不成正比例关系。通过承载能力计算值与实测值比较，发现两者误差在10%以内，满足工程精度要求。 |
| 关键词: 预应力 组合梁 负弯矩区 承载能力 |
| DOI： |
| 分类号:TU312 |
| 基金项目:国家杰出青年科学基金“水工混凝土结构工程”（51325904）；江苏省水利科技项目“江苏沿海水闸老化病害修复技术研究”（2012001-3） |
|
| Bearing capacity research of prestressed steel-concrete composite beams under action of negative bending moments |
|
HU Shao-wei
|
|
Nanjing Hydraulic Research Institute
|
| Abstract: |
| In order to evaluate the repairing effect of prestress reinforcement of the aging deteriorated concrete， studies of the flexural capacity in the negative bending moment zone of continuous composite beams with prestressed reinforcement are carried out. The static load tests of four prestressed composite beams under concentrated load are finished. The impacts of different shear connection degrees upon the mechanical performance of the prestressed composite beams are discussed, and the load midspan deflection characteristics of the beams are analyzed. The formulae for calculating elasticity and ultimate bearing capacity in the negative bending moment zone are established. The analysis results show that the flexural rigidity and the bearing capacity of full shear connection beams are greater than those of the partial shear connection beams, while the flexural rigidity and the bearing capacity are not in direct proportion to the shear connection degree. The comparison between the calculated and measured bearing capacity is made, and both errors are within 10%, so the results given by the new formulae can satisfy the engineering accuracy requirements. The calculation formulae derived for the flexural bearing capacity of the negative bending moment zone of the prestressed composite beam have some calculation accuracy in this paper, which is for design reference only. Since the calculated value of the ultimate flexural bearing capacity is less than the measured value, the calculated results given by this study are safer for the project design. |
| Key words: prestressed steel-concrete composite beam negative bending moment zone bending capacity |
