洛溪大桥拓宽工程双壁钢围堰结构受力分析

Stress Analysis of Double-Wall Steel Cofferdam Structure in Luoxi Bridge Widening Project

为了研究洛溪大桥拓宽工程Z3#主墩承台所用八边形双壁钢围堰挡水结构的力学性能,采用有限元软件ANSYS对该钢围堰关键施工阶段的受力特征进行仿真分析,以保证钢围堰在施工阶段的安全性。研究结果表明:1)钢围堰内封底混凝土达到设计强度,且围堰内的水抽干时所对应的工况为最不利工况,此时结构的最大变形为7.18 mm,出现在围堰横桥向壁板的中部;2)结构的最大应力为180.25 MPa,出现在水平横撑棱角附近,其中水平横撑处于第2节围堰下端至第1道内支撑的中间位置;3)在施工阶段中,八边形双壁钢围堰的变形和最大应力均小于设计值,结构刚度和强度满足要求。

Octagonal double-wall steel cofferdam is used as water retaining structure in the construction process of the Z3#main pier of Luoxi Bridge widening project,whose mechanical property has been seldom studied.The finite element software ANSYS is used to simulate and analyze the stress characteristics of the steel cofferdam in the key construction stage to ensure the safety of the steel cofferdam in the construction.The results show that:1)The most unfavorable working condition is when the inner sealing concrete of steel cofferdam reaches the design strength and the water in the cofferdam is completely drained.At this moment,the maximum deformation of the structure is 7.18 mm,which appears in the middle of the cofferdam panel in transverse direction;2)The maximum stress of the structure is 180.25 MPa,which appears near the corner of the horizontal brace that is located in the middle position from the lower end of the second cofferdam to the first inner support;3)In the construction stage,the deformation and maximum stress of the octagonal double-wall steel cofferdam are less than the design value,and the structural stiffness and strength meet the requirements.