摘要
针对乐山奥体中心体育场索膜罩棚西侧外高内低、东侧内高外低的不对称构形,提出并设计了一种车辐式单、双层组合索网结构,充分发挥单、双层索网各自特点,此类型组合索网结构系国内外首例。针对此类结构的找形方法、关键影响参数、力学特点、屋面排水组织、整体稳定性、抗倒塌性能、关键节点进行了研究。结果表明:采用以力密度法为基础的"虚拟撑扞法"找形无需进行迭代计算,且可直接控制结构主要参数,易于得到符合建筑外观要求的结构体型,便于结构参数化分析;车辐式单、双层组合索网竖向刚度主要由预应力大小决定,其余参数主要影响结构体型,其单层索网竖向刚度远小于双层索网,且存在"跷跷板"效应;西侧屋面积水可沿径向至内环,再沿环向至南北侧内环低点后,沿径向排放至外环;东侧屋面积水直接沿径向排放至外环,局部坡度较小处应设置附加排水设施,避免雨水淤积;双层索网上、下环索汇交成单层索网环索,使得双层索网上弦相对下弦扭转受到明显抑制,杜绝了此类结构发生内环扭转失稳可能。通过抗倒塌分析,保证了整体结构在偶然断索状况下的安全性。结合不同张拉方案,对车辐式单、双层组合索网结构关键节点方案进行对比分析,保证此类组合索网结构施工张拉的可实施性和便利性。
This paper proposes a spoke tension structure with single-layer and double-layer combined cable,which is the first application in the world on Leshan Olympic Center Stadium dome with an unsymmetrical shape.Some problems about the single layer and double layer combined cable design are discussed,such as form-finding method,key parameters,mechanics features,roof drainage measures,stability of cable structure,anti-collapse performance,and key joints.A form-finding method called‘virtual strut method’is proposed based on force density method,which avoids iteration and finds the cable structure shape directly and easily by changing performance parameters.The static analysis show that the structural rigidity of the single-layer cable is much smaller than the double-layer cable,which is controlled by prestress mainly,and the fall of the single-layer part will result in the rise of the double-layer part.Roof rainwater in the west flows to the inner ring,and then to the south or north circumferentially,and finally to outer ring radially.Meanwhile,roof rainwater in the east flows to the outer ring directly.Some additional drainage measures are needed to rain deposition in low slope places.It proves that the crossing of single-layer inner cable and double-layer inner cable can improve the stability of cable structure significantly.By cable-breaking analysis,it proves that damage of single radial cable will not lead to failure of the whole structure.Some key joints are proposed by comparing the mechanics and the construction convenience.
作者
吴小宾
陈强
冯远
刘宜丰
向新岸
李常虹
谢俊乔
WU Xiaobin;CHEN Qiang;FENG Yuan;LIU Yifeng;Xiang Xin'an;LI Changhong;XIE Junqiao(China Southwest Architectural Design and Research Institute CORP.,LTD,Chengdu 610000,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2022年第1期182-191,共10页
Journal of Building Structures
关键词
车辐式单、双层组合索网结构
虚拟撑扞法找形
极限承载力分析
断索分析
关键节点设计
spoke tension structure with single-double-combined layer cable
virtual strut method form-finding
analysis of ultimate bearing capacity
cable-breaking analysis
key joint design
