Long Span Continuous Girder Bridge Construction Control Study Of The Wind Area

Since2009our country to vigorously develop the high-speed rail, China’s railway bridge construction projects career has developed rapidly. Continuous girder bridge is an often seen on the railway bridge type, Continuous beam bridge with the construction of cantilever construction method, Structure undergoes a process of system transformation; In this process, The stress state and displacement of the bridge structure with a lot of uncertainty, Therefore, long-span continuous girder bridge finite element model calculation and strict construction control is necessary.In this paper, the second double of practical engineering Lan-Xin Huo expressway, cross-connected continuous girder bridge, this paper conducts simulation analysis to this bridge through the large-scale finite element software-MIDAS CIVIL. The main bridge of this bridge uses the existing railway with continuous beam; the span is60m+100m+60m. Adopting pouring Construction crafts of cantilever, the beam structure need successively experience the following process:Pier beam consolidation, consolidating pier beam, Pouring cantilever, folding side span concrete, removing temporary consolidation and folding middle span concrete. Error comparison is made between theoretical data obtained and measured data of construction process; through the comparative analysis, theoretical data and the measured data has a little deviation, but it is coinciding on the whole. The results of simulation calculation on construction control have guidance on actual construction process and provide basic guarantee and theoretical basis for the whole bridge folding smoothly.The close of the continuous beam bridge can be selected according to the actual construction conditions, Due to various reasons the construction finished on the2#Block after the bridge to change the close approach,Middle Cross Close by first changed to the first Edge Cross Close, By the software analysis, First in the beam cross close close paragraph displacement-18.65mm side span cantilever displacement of13.36mm; First Cross Close only4.67mm side span cantilever displacement-1.74mm. The two dead load construction phase, First in the beam cross close close paragraph displacement61.97mm side span cantilever displacement of-130.65mm;First Cross Close only-12mm side span cantilever displacement2.35mmThe end of February2007in Turpan, Xinjiang, A passenger train large wind turned; In late March of this year, the Urumqi City7winds blowing, Instantaneous wind of9, The strong winds caused by the Urumqi urban sections of the separation barrier, billboards, residential buildings, water heaters and building facades surface off. Hurricane have occurred in New Lan-Xin Railway second-line must pass through, Hurricane occurred with the continuous beam bridge together and time similar to. The construction of the bridge to take into account the Jiuquan and Urumqi in the same wind zone, Although the construction process has not yet encountered such a large wind, But does not rule out the possibility of its occurrence, Not yet close the bridge the maximum double cantilever, Wind analysis of the T structure is necessary. By the finite element software analysis, Under wind loads, The bridge maximum lateral displacement of the cantilever up to55.83mm, the vertical displacement of10.73mm. The construction process should pay close attention to weather changes and make precautions.