混凝土折板形柱面网壳结构静力性能的参数化分析

Parametric analysis of static performance of concrete folded-plate prismatic reticulated shell structure

通过等分柱面后,采用密肋平板交汇出混凝土折板形柱面网壳.基于有限元原理求解结构内力和挠度,并在此基础上考虑矢跨比及主拱、脊线、肋刚度和屋面板厚度等因素影响进行静力性能的参数化分析.结果表明,主拱是主要传力结构,脊线及平向肋内力较小,端隔在固支条件下主要由上弦传递荷载,边梁为双偏心受力构件,结构刚度主要由密肋平板控制.过大的矢跨比反而不利于结构刚度和强度控制,建议结构矢跨比不大于1/6;脊线刚度对结构整体刚度和承载力几乎没有影响,脊线截面高度可按构造确定.主拱刚度增加有利于调整结构的内力分布并提高屋盖的整体刚度,主拱截面高度可取屋盖跨度的1/80~1/100.肋刚度的提高有利于大幅度提高屋盖整体刚度,但对主拱内力影响较小,肋截面高度可取屋盖跨度的1/100~1/80.不建议采用过厚的屋面板.

The concrete prismatic plane multi-ribbed shell is consisted of ribbed plates which divide the prismatic plane equally.Internal forces and displacements are calculated by FEM.On this basis,the parametric analysis of static performance is condutted,considenng the effects of the rise-span ratio,the stiffness of the main arch,the ridges,the rib and the plate thickness.The results show that the main arch is the main force structure,and internal forces of the ridge and the flat rib are small.Vertical loads are transmitted by the top chord under clamped boundary conditions.The edge beam is a doubly eccentric force member,and the structural rigidity is mainly controlled by ribbed plate.Since too large rise-span ratio is not conducive to the stiffness and strength of the structure,it is suggested that the rise-span ratio is not greater than 1/6.The height of ridge section can be determined according to construction requirement due to the ridge stiffness has little influence on the overall stiffness and bearing capacity of the structure.The increase of main arch stiffness is conducive to adjusting the internal force distribution on structure and improving the roof stiffness,and the height of main arch section can be taken as 1/80~1/100 of the roof span.The increase of rib stiffness is beneficial to improving the roof stiffness,and it has less influence on the internal force of main arch,the height of rib section can be taken as 1/100~1/80 of the roof span.Thick roof panels are not recommended.