摘要
为研究预应力损失对大跨度PC连续梁桥桥梁性能的影响,采用MIDAS/CIVIL对某跨径布置为(60+100+100+60)m的PC连续梁桥进行计算分析,研究了纵向预应力的顶、底、腹板钢束在发生单一损失类型、双重组合损失类型和三重组合损失类型情况下,预应力损失程度对桥梁主跨跨中下缘压应力σ_(z)、主跨跨中挠度f_(l/2)和桥梁一阶自振频率n的影响,结果表明:无论发生何种损失类型,预应力损失程度与σ_(z)、f_(l/2)的关系均为线性相关规律;预应力损失将导致σ_(z)减小和f_(l/2)增大,其中,σ_(z)减小主要由顶、底板钢束预应力损失所致,f_(l/2)增大主要由底板钢束预应力损失所致,三重和双重组合损失类型相对于单一损失类型时的σ_(z)和f_(l/2)结果表现为叠加关系;桥梁一阶自振频率n不受纵向预应力损失影响。
In order to study the influence of prestress loss on bridge performance of longspan PC Continuous Beam Bridge,using MIDAS/CIVIL to calculate and analyze a PC Continuous Beam Bridge with span arrangement of(60+100+100+60)m,the influence of prestress loss degree on compressive stress at the lower edge of the main spanσ_(z),mid-span deflection of the main span f_(l/2),first-order natural vibration frequencyn of the bridge was studiedunder the conditions of single loss type,double combined loss type and triple combined loss type of longitudinal prestressed top,bottom and web steel strands.The results show that regardless of the type of loss,the relationship between the degree of prestress loss andσ_(z) and f_(l/2) is linearly related;the loss of prestress will lead to a decrease inσ_(z) and an increase in f_(l/2),among them,the decrease ofσ_(z) is mainly caused by the loss of prestress of the top and bottom plate steel strands,and the increase of f_(l/2) is mainly caused by the loss of the prestress of the bottom plate steel strands.The results of the triple and double combined loss types are superimposed relative to theσ_(z) and f_(l/2) results of the single loss type.The bridge's first-order natural vibration frequency n is not affected by the loss of longitudinal prestress.
作者
毛德均
余文正
许鹏
陈旭
王春华
MAO Dejun;YU Wenzheng;XU Peng;CHEN Xu;WANG Chunhua(College of Architecture and Civil Engineering, Kunming University, Kunming, Yunnan 650214, China;Yunnan Tongqu Engineering Testing Co. ,Ltd. , Kunming, Yunnan 650041, China)
出处
《公路工程》
2022年第2期26-31,共6页
Highway Engineering
基金
云南省地方本科高校基础研究联合专项资金青年项目(2019FH001-100)
云南省教育厅科学研究基金项目(2020J0512)
国家自然科学基金项目(51868034)。
关键词
PC连续梁桥
预应力损失影响
有限元
压应力
跨中挠度
自振频率
PC continuous girder bridge
influence of prestress loss
finite element
compressive stress
mid-span deflection
natural vibration frequency
