预应力损失对大悬臂混凝土盖梁开裂研究  

Study of Prestress Loss on Cracking of Large Cantilever Concrete Covered Beam

作　　者：薛江 刘金城 李自林 XUE Jiang;LIU Jin-cheng;LI Zi-lin(School of Civil Engineering,TCU,300384,Tianjin,China;Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,300384,Tianjin,China;Hebei Key Laboratory of Geotechnical Engineering Safety and Deformation Control,061001,Cangzhou,Hebei,China;College of Civil Engineering,Hebei University of Water Resources and Electric Engineering,061001,Cangzhou,Hebei,China)

机构地区：[1]天津城建大学土木工程学院,天津市300384 [2]天津市土木建筑结构防护与加固重点实验室,天津市300384 [3]河北省岩土工程安全与变形控制重点实验室,河北省沧州市061001 [4]河北水利电力学院土木工程学院,河北省沧州市061001

出　　处：《河北水利电力学院学报》2022年第3期37-43,共7页Journal of Hebei University Of Water Resources And Electric Engineering

基　　金：天津市科技计划项目(20YDTPJC0060),天津市教委科研计划项目(2017KJ047),国家自然科学基金项目(52108333)。

摘　　要：随着大悬臂预应力混凝土桥梁使用年限的增加,在运营检测过程中发现,部分桥梁的盖梁横桥向侧面出现了较多竖向或斜向、网状裂缝。以石家庄某桥梁为例,利用有限元软件,研究影响大悬臂预应力混凝土盖梁预应力损失的因素,分析预应力管道局部偏差、环境相对湿度、超早强混凝土以及预应力张拉龄期等四种因素对于盖梁开裂的影响程度。结果表明:前期各因素对混凝土拉应力影响均较小。在中后期,超早强混凝土对预应力盖梁的承载力的影响最大;其次为环境相对湿度;然后为预应力张拉龄期;最后是管道局部偏差。通过对比以上因素,确定对10年内盖梁拉应力的影响程度,进而指导施工,减小施工因素对盖梁拉应力的影响,提高盖梁使用寿命。With the increase of the service years of large cantilever prestressed concrete bridges,it is found in the process of operation inspection that there are many vertical or oblique and network cracks in the transverse side of some bridges.Taking a bridge in Shijiazhuang as an example,the factors affecting the prestress loss of large cantilever prestressed concrete bent cap are studied by using finite element software,and the influence of four factors such as local deviation of prestressed pipeline,environmental relative humidity,ultra early strength concrete and prestress tensioning age on the cracking of bent cap is analyzed.The results show that all factors have little influence on the tensile stress of concrete in the early stage.In the middle and late period,the influence of super early-strength concrete on the bearing capacity of prestressed girder is the greatest,followed by the relative humidity of the environment,then the tensile age of prestress,and finally the local deviation of the pipeline.Through the comparison of the above factors,the influence degree of the tensile stress of the cover beam in 10 years is determined so as to guide the construction,reduce the influence of construction factors on the tensile stress of the cover beam and improve the service life of the cover beam.

关 键 词：大悬臂盖梁 混凝土开裂 收缩徐变 管道摩擦 

分 类 号：U445.7[建筑科学—桥梁与隧道工程] TU378.2[交通运输工程—道路与铁道工程]