虎跳门特大桥施工控制计算分析

Calculation and Analysis of Construction Control of Hutiaomen Bridge

广珠铁路虎跳门特大桥为连续刚构-柔性拱桥,主桥跨度布置为(120+248+120)m。采用MIDAS软件建立该桥三维有限元模型,计算施工过程中结构线形和内力,并与设计结果对比;按第一类稳定问题验算拱肋稳定性;对存在的参数进行识别、分析。结果表明:施工过程中结构线形和内力均满足相关规范要求;拱肋面内、面外稳定性安全系数分别为4.99和4.98,满足使用要求;混凝土容重、钢束初张拉力和施工临时荷载为该桥结构的高敏感性参数,施工控制中应重点监测、识别和调整。

The Hutiaomen Bridge on Guangzhou-Zhuhai Railway is a continuous rigid-frame and flexible arch bridge with span arrangement for the main bridge being（120＋248＋120） m.The three-dimensional finite element models for the bridge were established by the MIDAS software,the geometric shape and internal force of the bridge structure in the construction process were calculated and the calculations were compared with the design.The calculation of the arch ribs of the bridge was checked in accordance with the Category I Stability and the existing parameters were identified and analyzed as well.The results show that the geometric shape and internal force of the structure in the construction process can all meet the requirements in the relevant codes,the safety factors of the in-plane and out-of-plane stability of the arch ribs are respectively 4.99 and 4.98 and can satisfy the service requirements.The unit weight of concrete,the initial tensioning force of steel strands and the temporary construction load are the parameters of the structure that are highly sensitive,which should be particularly monitored,identified and adjusted in the construction control.