三门峡黄河公铁两用特大桥6#墩双壁钢套箱围堰设计

摘要

The main bridge of the new built Sanmenxia Yellow River rail-cum-road super long bridge of Inner Mongolia-China railway is a 11-span continuous steel truss girder bridge with total length of 1 140 m.The Yellow River main channel is wide and flood and non-flood water levels vary widely.The maximum water level difference can reach 13 m.The No.6 pier is a rectangular platform and around the corner with a round angle,which plane size is 42.3 m×24.6 m,the thickness is 4.5 m.The cofferdam is a double-walled steel box cofferdam,which plane size is 46.5 m×28.8 m,the height is 22.9 m,the wall thickness is 2 m.The cofferdam is mainly composed of side plate, horizontal ring plate,horizontal angle steel and partition board.According to the different states and the most unfavorable state of the cofferdam in the construction process,it is divided into three working conditions.The MIDAS/Civil 2012 and the large scale general f inite element software ABAQUS were used to establish the models of each working condition to analyze the displacement and stress of the cofferdam and the bottom concrete.The results show that under the different conditions,the maximum displacement and stress of the cofferdam and the bottom concretes are less than the standard allowable values,and meet the requirements of the specif ication.%新建蒙华铁路三门峡黄河公铁两用特大桥主桥为11跨连续钢桁结合梁桥,全长1140 m.黄河主河槽较宽,汛期和非汛期水位变化较大,最大水位高差可达13 m.6#墩为矩形承台,平面尺寸42.3 m×24.6 m,厚4.5 m,四周倒以圆角;围堰采用双壁钢套箱围堰,双壁钢套箱围堰平面尺寸为46.5 m×28.8 m,高度为22.9 m,壁仓厚2 m.围堰主要由侧板、水平环板、水平角钢与隔舱板组成.根据施工过程中围堰受力情况的不同及最不利状态分3个工况,采用MIDAS/Civil 2012和大型通用有限元软件ABAQUS建立各工况的有限元模型,分析围堰及封底混凝土结构的位移及应力.结果表明,在各个工况下,围堰及封底混凝土结构的最大位移及应力均小于规范允许值,满足规范要求.