大跨度预应力混凝土箱梁桥腹板
抗裂敏感性与配索优化分析
赵启林，丁 勇，翟可为
(中国人民解放军理工大学工程兵工程学院，江苏南京 210007)
摘要：针对各国大量悬浇预应力混凝土箱梁桥出现腹板斜裂缝，且腹板单纯配置竖向索的桥梁比腹
板设置下弯索的开裂更为严重的现象，采用敏感性分析方法对单纯采用竖向索和单纯采用下弯索
的腹板抗裂性进行了对比分析；针对腹板不仅存在剪应力而且存在竖向拉应力的客观事实，证明了
下弯索无法克服腹板竖向拉应力导致的主拉应力，指出腹板进行竖向索与下弯索混合配置的必要
性，且推导出了腹板竖向索与下弯索的合理配置比例。结果表明：在其他因素相同的情况下，采用
竖向索抗剪的腹板抗裂可靠性明显低于采用下弯索的腹板抗裂可靠性。
关键词：斜裂缝；大跨度；预应力混凝土箱梁桥；腹板；敏感性
中图分类号：U448．213 文献标志码：A
Analysis of W eb Anti_‘crack Sensitivity and Tendon--collocating Optimization
for Long‘。span Prestressed Concrete Box--girder Bridge
ZHAO Qi—lin，DING Yong，ZHAI Ke—wei
(School of Engineering Corps，PI A U niversity of Science and Technology，
Nanjing 210007，Jiangsu，China)
Abstract：The inclined cracks in webs of prestressed concrete box—girder bridge with suspended
construction took place frequently，and it was more common in these with pure vertical tendons
than those with bending ones． Comparison of web anti—crack property was conducted between
them with the method of sensitivity analysis．Bending tendons were proved not tO overcome the
principal stress due tO vertieal tensile stress with the fact that vertical tensile stress exists as well
as shear in webs．The need of mixed configuration with bending tendons and vertical ones was
highlighted，and suitable proportion between vertical and bending tendons was given． The results
indicate the webs with bending tendons are more reliable than those with pure vertical ones
obviously even under the same condition．
Key words：inclined crack；long span；prestressed concrete box—girder bridge；web；sensitivity
引 目
采用悬臂法施工的预应力混凝土桥梁一般采用
悬臂索下弯、设置竖向预应力钢筋或下弯索与竖向
索混合设置3种方法来抵消腹板由剪应力产生的主
拉应力。但是随着桥梁运营年限的增加，大量该类
桥梁出现了挠度过大的现象，且在出现挠度过大的
同时必然伴随腹板开裂⋯ 。根据交通运输部公路科

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