研究目的：于家堡火车站是新建京津城际延伸线终点站，穹顶是由36根正反螺旋型网格相互编织而成的单层网壳结构。网壳网格形式特殊新颖且跨度达143 m，整个结构受力非常复杂。本文旨在根据网壳结构的整体受力特点和边界条件，确定网壳合适的支座方案。
研究结论：（1）支座是网壳结构与下部支承结构连接的关键构件，支座方案的优劣直接关系到网壳边界条件假定是否成立；（2）在确定支座的反力时，既要考虑支座的转动中心与计算模型转动中心不重合引起的附加弯矩的影响，也要考虑罕遇地震工况组合下的反力；（3）穹顶的双铰支座由沿底环梁形心联合转动的底面球型钢支座和侧面球型支座组成，两个支座的中间球面板具有相同的曲率半径，其满足计算假定的边界条件，是一种新型的支座方案；（4）对双支座进行有限元分析和缩尺的加载及转动试验，结果均验证了支座各组成部件的应力和转动性能满足设计要求；（5）双铰支座方案的研究成果可供类似单层网壳结构参考。

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Abstract：Research purposes：The dome of newly-built Yujiapu railway station in Beijing-Tianjin intercity line extension is a single layer shell structure, which is weaved by 36 positive and negative spiral grid. The shell with a long span of 143 m is novel and complex. This paper researches the force characteristics and boundary conditions in order to choose the suitable support programs of the shell.
Research conclusions：（1）Bearing is a key component of the connecting shell structure. The lower part of the support structure, support program is directly related to the assumed boundary conditions of the shell.（2）In determining the bearing reaction force, not only consider that the effect of the rotation center and the calculation model of bearing rotation center does not coincide with the additional bending moment, but also consider the rare earthquake force.（3）Double hinged bearing which is made of horizontal spherical steel bearing and vertical spherical steel bearing rotates along the bottom beam ring centroid, and satisfies the boundary condition. We use non-earthquake and rare earthquake condition of bearing reaction force envelope to do double hinged bearing arrangement in detail.（4） We conducted a double hinged bearing finite element analysis and a reduced scale test to verify that the stress and rotation performance meets the design requirements. （5）The research results of innovative double hinged bearing can provide references for similar projects. 
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