摘要
奉化江南翔桥为(80+130+80)m双幅三跨V形墩混凝土连续刚构桥,V形墩斜腿采用单箱双室预应力钢筋混凝土箱形结构。为确保该桥通行安全,了解V形墩在运营状态下的实际极限承载力,采用有限元法建立V形墩三维实体非线性模型,定量分析承载能力极限状态及正常使用极限状态下,以允许活载超载系数K为表征的V形墩极限承载力,并结合现场监测数据,对K值进行修正。结果表明:V形墩在截面承载能力极限状态下的允许K值约为9,破坏形态为大偏压破坏;在正常使用极限状态下的允许K值约为6,由截面边缘最大压应力控制;在V形墩的钢筋应力及裂缝宽度限制条件下的允许K值约为6;以V形墩实测的成桥应力代替相应状态下的理论值,修正后的允许K值约为4.9,该桥V形墩在运营状态下的实际极限承载力较高。
T he Nanxiang Bridge crossing Fenghua River is a threespan continuous concrete rigidframe bridge with span arrangement of（80＋130＋80） m .The bridge has two separated decks and Vshaped piers .The inclined legs of the Vshaped piers adopt the twocell single box prestressed reinforced concrete box structure .To ensure the operation safety of the bridge and investigate into the actual ultimate load bearing capacity of the Vshaped piers in service condition ,the finite element method was used to establish the threedimentional solid nonlinear models of the Vshaped piers for the purpose of doing quantitative analysis of the limit state of load bearing capacity ,and the ultimate load bearing capacity of the Vshaped piers represented by the allowed live load overload coefficient K under the limit state of normal operation .And the K was in turn modified in accordance with the field monitoring data .The results of the analysis indicate that the allow ed K is about 9 in the limit state of cross section load bearing capacity of Vshaped piers and the failure mode belongs to large eccentric loading failure .Under the limit state of normal service condition ,the allowed K is about 6 ,governed by the maximum compressive stress in the edge of the cross section .Under the restriction of reinforcement stress and crack width of the Vshaped piers , the allowed K is about 6 .To use the measured stress of the Vshaped piers in the completed bridge state to replace the theoretical values in the related condition ,the allowed K is about 4 .9 after modification .T he actual load bearing capacity of Vshaped piers of the bridge under the operation condition is higher .
出处
《世界桥梁》
北大核心
2014年第6期41-45,共5页
World Bridges
关键词
连续刚构桥
V形墩
极限承载力
超载系数
监测数据
修正
有限元法
非线性分析
continuous rigid-frame bridge
V-shaped pier
ultimate load bearing capacity
overload coefficient
monitoring data
modification
finite element method
non-linear analysis
