连续钢梁顶推过程局部接触分析及改善措施

Local contact analysis and improvement measures of continuous steel girder incremental launching

为了研究大跨度连续钢梁顶推的局部受力特性,以6×90m变曲率竖曲线连续钢梁顶推为研究对象,根据梁不动、下部支撑移动的"倒退"方法,采用商用程序MIDAS 2006建立顶推整体有限元模型,并对其进行仿真分析。在此基础上,根据顶推整体仿真计算结果,选取滑道处钢梁最不利工况,借助EXCEL和CAD等辅助工具,运用ANSYS的APDL语言快速建立"梁-壳-实-接触"混合有限元模型。理论和实测值均表明:最不利工况下滑道处钢梁局部受力满足要求,但转角位移过大。结合工程实际情况,提出了2种有效改善措施:第一种采用台阶导梁;第二种采用台阶导梁、压重和增大部分钢梁截面刚度的组合方式。

In order to study local force characters of the large span continuous steel tank girder incremental launching, taking a 6× 90 m vertical curve of variable curvature continuous steel girder as the research object, the whole simulation model was set up by the software MIDAS 2006 with ＂beam remain still and only lower supports reverse move＂ method. Then based on the analysis re- suits of the whole girder, a ＂beam-shell-solid-contact＂ hybrid finite element model was set up with ANSYS APDL and by means of Excel and CAD assistance under the unfavorable condition. The theoretical and measured values show that the steel girder local force meets the requirements at the sliding part, but the angular displacement is too large. According to the actual engineering situation, two effective improvements are suggested to solve a series of problems which are caused by the exaggerated angular displacement, the one is that the steps nose beam is adopted in the first measure, the second measure adopt a combination of steps nose beam, weights and in- creasing the stiffness of part of the steel beam. 6 tabs, 9 figs, 13 refs.