上承式钢管混凝土拱桥钢管生命全过程应力状态分析

Analysis of Stress State in the Whole Life Process of Concrete Filled Steel Tubular Arch Bridge

为研究钢管混凝土拱桥钢管生命全过程应力状态,利用有限元软件MIDAS/CIVIL准确模拟杆件的空间尺寸、材料特性、连接方式及初始应力等,对无扣索条件下合拢桁架空钢管拱肋,空钢管带拱上立柱、灌注4根下弦杆混凝土以及灌注上弦杆、服役过程等生命全过程工况进行划分,主要为10个工况,分析了钢管生命全过程的应力状态。结果得出:上下弦钢管在生命全过程中应力不断增大,但未超限;拱肋上下弦钢管应力存在一定的偏差,拱脚附近和L/4处钢管下弦比上弦分别大81.1%和7.4%,拱顶则是上弦比下弦大55.1%;生命全过程中拱脚和拱顶的钢管应力为最不利截面,在施工及服役阶段都应对其重点监测。

To study the life-cycle stress state of concrete-filled steel tubular arch bridge, the finite element software MIDAS/CIVIL was used to accurately simulate the space dimensions of component, ma-terial properties, connecting details and initial stress, etc. The whole bridge was divided into 10 cases, for example, empty steel tube without hanger cable, empty steel tubes with columns on the rib, casting concrete in bottom chord, casting concrete in upper chord, and service process, to analyze the whole process stress state of the steel tube. The results show that the stress of the upper and lower steel tube increases continuously in the whole life process, but does not exceed the limit. The stresses of the steel tube at the upper and bottom chords of the arch rib have a certain deviation. The stress of lower chord of the steel tube near the arch foot and L/4 span are respectively 81.1% and 7.4% larger than those of the upper chord, while the arch top is 55.1% larger than that of the bottom chord. The stresses of steel tube at arch foot and arch top are the most unfavorable sections in the whole life process.