摘要
人字形密肋网壳由密肋平板在脊线处相交构成.为了解网壳屋盖与下部结构在竖向荷载作用下的共同工作性能,基于位移法求解了屋盖的内力,采用有限元方法对比计算了点支承屋盖和整体结构屋盖的内力及变形.在此基础上考虑下部结构抗侧刚度、屋盖矢跨比和肋刚度的影响计算了25个算例.结果表明:顶层抗侧刚度和矢跨比是影响屋盖内力的主要因素,屋盖轴力和矢跨比呈非线性关系;屋盖具有较强的拱向传力性质,脊线类似于拱的系杆;与点支承屋盖相比,共同工作使横隔下弦的内力明显增大,并引起下部楼盖轴力,且屋盖边梁应按双偏心受力构件计算承载力;顶层采用异型柱是调整屋盖内力分布的有效措施,当异型柱演化为短肢剪力墙时,建议墙肢长度取屋盖一个投影网格长度;增大矢跨比有利于降低屋盖挠度,屋盖内力分布对矢跨比较为敏感,矢跨比不宜低于1/6;过大的肋刚度对提高屋盖整体承载力意义不大,肋截面高度可取屋盖跨度的1/40~1/50.
This paper aims to study the interaction performance between substructure and concrete herringbone multi-ribbed shell which is formed by ribbed plates intersecting at ridge.The internal force of the roof under vertical loads is obtained by displacement method,and the internal force and deformation of point supported roof as well as the whole roof are calculated by FEM.On this basis,25 structures are calculated to consider the effects of the lateral stiffness of substructure,the rise-to-span ratio and the rib rigidity.The results show that the relation between axial force and rise-to-span ratio of the roof is nonlinear,and internal force of the roof is mainly influenced by lateral stiffness of top floor and rise-to-span ratio of the roof.Vertical load is mainly transferred along the arches which are connected by the ridge.Compared with the point-supported roof,the internal force of the bottom chord of diaphragm on the whole roof is increased obviously,the lower floor beams have axial force,and the bearing capacity of roof edge beams should be calculated under biaxial eccentric load.A measure that special-shaped column is applied the to top layer of the structure can effectively adjust internal force of the roof,and the length of short-leg shear wall which is transformed by special shaped column can adopt a projected grid length of the roof.Although the increase of the rise-to-span ratio can reduce deflection of the roof,the distribution of internal force of the roof is significantly affected by the rise-to-span ratio which should not be less than 1/6.Overlarge rib stiffness is not effective for improving overall bearing capacity of the roof,and the height of the rib section can be taken as 1/40~1/50 of the roof span.
作者
齐卫东
张华刚
方强
李莉
马克俭
QI Wei-dong;ZHANG Hua-gang;FANG Qiang;LI Li;MA Ke-jian(Space Structures Research Center, Guizhou University, Guiyang 550003, China;College of Civil Engineering, Guizhou University, Guiyang 550025, China;Shenzhen Institute of Building Research Co. , LTD, Shenzhen 518049, China)
出处
《空间结构》
CSCD
北大核心
2017年第4期36-44,共9页
Spatial Structures
基金
国家自然科学基金项目(51568012)
贵州省科学技术基金项目(黔科合J字[2008]2112号)
关键词
人字形密肋网壳
混凝土
下部结构
共同工作
静力性能
herring-bone multi-ribbed shell
concrete
substructure
interaction
static behavior
