混凝土人字形密肋网壳与下部结构共同工作性能分析

发布时间：2018-07-31 19:37

【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.
[Abstract]:The herringbone-ribbed reticulated shell consists of a multi-ribbed plate intersecting at the ridge. In order to understand the common working performance of reticulated shell roof and substructure under vertical load, the internal force of the roof is solved based on the displacement method, and the internal force and deformation of the point supported roof and the whole structure roof are compared and calculated by using the finite element method. On this basis, the effects of lateral stiffness, sagit-to-span ratio and rib stiffness of the substructure are taken into account. The results show that the lateral stiffness and the rise-span ratio of the top floor are the main factors affecting the internal force of the roof, and the axial force and the rise-span ratio of the roof are nonlinear, and the roof has a strong arched transmission property, and the ridge is similar to the tie bar of the arch, and compared with the point-supported roof, The joint work increases the internal force of the lower transverse chord and causes the axial force of the lower floor, and the bearing capacity of the edge beam of the roof should be calculated according to the double eccentricity force, and the adoption of special shaped columns on the top floor is an effective measure to adjust the distribution of the internal force of the roof. When the special-shaped column evolves into a short shear wall, it is suggested that the length of the wall limb should be taken as a projective grid length of the roof, and the deflection of the roof can be reduced by increasing the rise-to-span ratio, and the distribution of the internal force of the roof is more sensitive to the rise-to-span ratio. The ratio of rise-to-span should not be less than 1 / 6; too large ribbed stiffness is of little significance to improve the overall bearing capacity of roof, and the height of rib section can be taken as 1 / 40 / 1 / 50 of the span of roof.
【作者单位】：贵州大学空间结构研究中心;深圳市建筑科学研究院股份有限公司;贵州大学土木工程学院;
【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)
【分类号】：TU31

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