常德芦荻山收费站全张拉索膜结构预应力施加数值模拟与施工监测

SIMULATION AND MONITORING OF WHOLE ERECTION PROCESS FOR THE CHANGDE LUDISHAN TOLL STATION

采用MIDAS/Gen和ANSYS有限元分析软件对常德芦荻山收费站全张拉预应力索膜结构的预应力施加过程进行数值模拟,对该结构的初始应力状态进行反复试算,得出最佳索力初始应力;为确保施工过程中的索力预张力施工的可靠性及施工安全性,对该结构中主结构索力施加的施工全过程索力、位形以及桅杆应力监测。研究表明：整体张拉结构形式预应力的施加宜采用先同步张拉背索,然后张拉谷索的方法使整体结构成形;在预应力施加初始阶段结构变形量较大,预应力的施加过程应分级缓慢加载;张拉过程中,桅杆在动态过程中应力变化比较复杂,对钢桅杆的应力监测十分必要。模拟结果与监测结果吻合较好,表明该数值模拟方法切实可行,施工过程中结构关键杆件应力、索力及位移在可控范围之内,施工方案可以很好地满足设计要求。

MIDAS/Gen and ANSYS software were used to carry out the numerical simulation of the prestressed tension and the cable-membrane structure of the pretressing cable tension of the Changde Ludishan Toll Station Building＇s construction progress,and by experimenting test repeatedly on the structure＇s original stress state,the best original stress of cable tension was obtained. In order to ensure the reliability and secuirity of cable tension of the construction during the work progress, the cable tesion monitoring, configuration monitoring and mast stress monitoring were carried out all through the work progress. The research results indicated that,it was proper to adopt synchronous stretch-draw dorsal funiculus,and then the way of stretch-draw valley was capable of shaping the whole contructure. In the prilimelary stage of exerting prestressed force,when the deflection was comparatively large,exerting prestressed force should be slowly gradation loading. In the prosess of tession,the dynamic variation of stresses of the mast was complicated,so it was necessary to carry out the stress monitoring of the steel mast. The simulation results agread well with the monitoring results,it indicated that the way of numerical simulation was practicable. The key structure levers force and cable tension and displacement were controlable during the construction,and the construction program could greatly meet the requirements of the design.