太原植物园大跨胶合木网壳结构设计关键技术研究

Research on key technologies of large-span glued laminated timber reticulated shell structure design in Taiyuan Botanical Garden

太原植物园温室建筑造型呈"贝壳"形状,其中1#温室最大跨度为89.5m,最大高度29.5m,采用双向叠放胶合木梁形成网壳结构体系,在胶合木梁下部设置双向拉索,拉索和胶合木梁之间通过倒四角锥拉杆形成整个温室结构体系。提出了新型"Z"形木梁拼接节点和木梁叠放节点,可有效避免双向木梁在节点区被打断造成刚度削弱和连接困难,同时也满足了建筑效果的需求,该节点的设计保证了胶合木网壳结构体系的成立。进一步研究了倒四角锥拉杆节点及安装方法,可有效避免现场张拉索网的难题,并给出了一种索网结构的张紧安装方法。通过控制索的初始预应力来提高结构整体刚度和稳定性,采用几何非线性方法对结构进行各工况计算,并进行了特征值分析和极限承载力分析,验证了新型结构体系的可靠性,对拓展国内大跨度胶合木建筑的发展具有重要意义。

The greenhouse building model in Taiyuan Botanical Garden is shaped like a"shell".The 1#greenhouse has a maximum span of 89.5 m and a maximum height of 29.5 m.Two-way laminated glulam beams are used to form a reticulated shell structure system.Two-way cables are set at the lower part of the glulam beam.The whole greenhouse structure system is formed between the cables and the glulam beam through inverted four corner cone pull rods.A new"Z"shaped wood beam splicing joint and wood beam stacking joint were proposed,which can effectively avoid the stiffness weakening and connection difficulties caused by the interruption of two-way glulam beams in the joint area,and also meets the needs of architectural effects.The design of the"Z"shaped wood beam splicing joint ensures the establishment of the glued laminated timber reticulated shell structure system.The inverted four corner cone pull rod joint and its installation method was further researched,which can effectively avoid the problem of tensioning the cable net on site,and a tensioning installation method of the cable net structure was given.By controlling the initial prestress of the cable to improve the overall stiffness and stability of the structure,the geometric nonlinear method was used to calculate the working conditions of the structure,and the eigenvalue analysis and ultimate bearing capacity analysis were carried out to verify the reliability of the new structural system,which is of great significance to expand the development of long-span glulam buildings in China.