某隧道出入口大跨度曲面弧形箱型钢梁屋盖体系设计

Design of the large-span curved steel box beam roof system at the entrance and exit of a tunnel

弧形箱形钢梁体系适用于曲面建筑造型的大跨度空间屋盖结构,在空间结构领域应用广泛。首先以某隧道出入口大跨度弧形钢梁屋盖体系为例,研究了该体系的结构各部件组成、承载模式、基础布置以及刚性节点和支座的详图做法;接着对该结构体系的应力、位移和支座反力等整体受力性能进行了分析;最后引入首阶屈曲模态作为初始缺陷,对该结构体系的材料、几何双重非线性稳定极限承载性能进行了研究。结果表明,弧形箱形主钢梁主要承受轴压作用,最大z向位移出现在矢跨比较小的右侧弧形钢梁屋盖顶部区域;非线性屈曲分析时的极值点荷载系数为9.75,具备较好的稳定承载性能。

The curved steel box beam system is suitable for large-span space roof structure with the curved surface and is widely used in the field of the spatial structure.Firstly,taking a large-span curved steel beam roof system at the entrance and exit of a tunnel as an example,the composition of various components,the bearing mode,the foundation layout and the detailed construction of rigid joints and supports were studied.Then,the overall mechanical performance such as the stress,the displacement and the bearing reaction force of the structural system were analyzed.Finally,by introducing the first-order buckling mode as the initial defect of the structure,the ultimate stability bearing capacity with the dual nonlinearity of the material and the geometry was studied.The results show that the curved steel box beam is mainly subjected to the axial compression,and the maximum Z-direction displacement occurs in the top area of the right curved steel beam roof with the small rise-span ratio;the load coefficient of the extreme point in the nonlinear stability analysis is 9.75,which has good stability bearing capacity.