基于无应力状态法的悬臂拼装斜拉桥的线形控制

针对悬臂拼装斜拉桥的线形控制问题,以穗盐路斜拉桥为背景,提出基于无应力状态法理论以钢箱梁制造线形为目标,进行主梁线形控制的方法。该桥为对称独塔双索面塔梁固结体系,采用MIDAS Civil建立桥梁有限元模型,分析钢箱梁在不同施工临时荷载作用下的制造线形和安装线形。分析结果表明,该桥安装线形随施工临时荷载的不同而改变,制造线形是结构的稳定量,只要保证梁段的无应力状态量一定,则无应力线形是惟一的;实桥安装时按制造线形夹角进行安装,无论施工过程如何改变,最终成桥阶段的内力和位移与理想目标状态一致。

Geometric Shape Control of Cantilever Assembled Cable-Stayed Bridge Based on Unstressed State Method

In view of the problem of geometric shape control of the cantilever assembled cable-stayed bridge,the Suiyan Road Cable-Stayed Bridge was cited as an example and a method for the geometric shape control of main girder of the bridge based on the unstressed state method theory and taking the geometric shape of manufacturing of the steel box girder for the main girder as the goal was proposed.The bridge as cited is a single-pylon and double-cable-plane structural system with rigid fixity of its pylon and girder and with symmetric span arrangement.The MIDAS Civil was used to set up the finite element model for the bridge and to analyze the geometric shapes of manufacturing and assembling of the steel box girder of the bridge under the action of different temporary construction loads.The results of the analysis reveal that the geometric shape of assembling of the bridge changes with the changing of the temporary construction loads.The geometric shape of manufacturing is the stable amount of the structure and as long as the unstressed state amount of the blocks of the girder is kept to a given amount,the unstressed geometric shape will be the only.At the time the actual bridge is assembled,the bridge should be assembled according to the included angles of the geometric shape of manufacturing and in spite of the changing of the construction process,the internal forces and displacement of the final completed bridge will be agreeable with those of the ideal target state.