摘要
为研究全体外预应力节段拼装梁的极限应力和抗弯承载力,提出了基于全体外预应力节段拼装梁变形和预应力增量相协调原理的计算方法。该方法将体外预应力增量分为梁体线弹性未开裂阶段和开裂后阶段两部分,分别推导出两阶段预应力增量,考虑预应力二次效应,建立以梁体转角θ为参数的全体外预应力节段拼装梁极限应力和桥梁抗弯承载力计算公式。为验证公式的准确性,以芜湖长江公路二桥引桥40 m全体外预应力节段拼装梁为背景,开展足尺模型试验,并与国外学者的试验数据进行对比。结果表明:所提出的公式计算值与试验实测值误差较小,该公式可准确计算全体外预应力节段拼装梁的极限应力;为简化计算,在工程设计时转角θ可取0.0176°,转角θ取值与国外学者的试验数据具有较好的一致性;根据极限应力增量推导的抗弯承载力计算公式可预估桥梁抗弯承载力,指导工程设计。
In this paper,a method to calculate the ultimate stress in and flexural bearing capacity of precast segmental girders with full external prestressing is proposed,which is developed premised on the balance of girder deformation and external prestressing increment.By this method,the external prestressing increment is divided into the two stages of linear elastic uncracking and cracking of the girder body,then,the two-stage increments are derived,based on which,the formulas to calculate the ultimate stress in and flexural bearing capacity of the precast segmental girders with external prestressing are developed,which take the girder body rotation angleθas a parameter and consider the secondary effect of prestress.The 40 m-long segments of the approach viaducts of the Second Wuhu Changjiang River Highway Bridge that were assembled with full external prestressing is used as a case to verify the accuracy of the formulas.The full-scale model test results were compared with the findings of other scholars at home and abroad.It is shown that there is a minor difference between the calculations of the presented formulas and the existing test data,proving that the presented formula is effective in calculating the ultimate stress of the precast segmental girders with external prestressing.To simplify the calculation,the recommended value of girder body rotation angleθis 0.0176°,which is in good agreement with the test results of the scholars at home and abroad.The formulas to calculate the flexural bearing capacity derived on the basis of the ultimate stress increment can be used to estimate the flexural bearing capacity of the bridge and guide engineering design.
作者
杨大海
陈修和
查甫生
YANG Da-hai;CHEN Xiu-he;ZHA Fu-sheng(Anhui Transport Consulting&Design Institute Co.,Ltd.,Hefei 230088,China;Research and Development Center on Technology and Equipment for Energy Conservation and Environmental Protection of Highway Transport,Hefei 230088,China;School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2022年第2期104-111,共8页
Bridge Construction
基金
《公路装配式混凝土桥梁设计规范》编制项目([2018]244)。
关键词
节段拼装梁
全体外预应力
极限应力
抗弯承载力
计算方法
足尺模型试验
precast segmental girder
full external prestressing
ultimate stress
flexural bearing capacity
calculation method
full-scale model test
