新光大桥三角刚架施工过程模型试验及有限元分析

结合广州新光大桥采用1：10的缩尺模型试验和有限元有限元分析，根据相似理论设计了加载方案和配重方案，针对缩尺模型重力效应问题，采用加多点施加竖向荷载的方式补偿。重点研究了三角刚架在施工阶段中斜腿悬臂施工时对拉预应力杆的张拉力和放张时机，以及斜腿由悬臂变为刚构的体系转化过程中的正应力发展和分布规律、混凝土开裂可能性等问题。依据试验数据和计算结果对三角刚架的施工方法以及预应力张拉、拉杆拆除等重要施工工艺进行了深入讨论。结果表明在施工阶段三角刚架的最大压应力出现在斜腿根部、最大拉应力出现在斜腿项部，预应力张拉及拉杆拆除的顺序对拉应力有较大影响。

Model Test and FEM Analysis on Tri-angle Frame of Xinguang Bridge

As the most important structure in continuous frame arch bridge, model test and FEM analysis of triangle frame used for Xinguang bridge was presented. In the experiments and calculation analysis, distribution and evolvement of normal section stress, and anti-cracking ability were carefully measured and studied, construction scheme and the order of pre-stress tension and tie-bar unloading was carefully discussed. The result shows that the maximum pressing stress exists at the end of inclined column, the maximum tension stress exists at the top of inclined column, and the order of pre-stress tension and tie-bar unloading have an influence on the tension stress.