Analysis Of The Joint Performance Of The Herringbone Ribbed Shell And The Lower Structure

The concrete herringbone ribbed folded plate latticed shell is a kind of innovation system structure,enriching the concrete shell structure in the form of the shell and creating a new field of large span concrete shell.The structure has a natural drainage slope,durability and fire resistance,in line with the concept of green building.Using the assembly type construction promotes the construction level.In general discussing the concrete herringbone ribbed folded plate latticed shell has the great academic value and scientific significance.In order to understand the working performance of the reticulated shell roof structure and the lower structure,this paper studies the static and dynamic forces and the key technologies of the roof and the substructure.The results show:The axial force and height-to-span of roof are nonlinearly related,internal force of roof are mainly influenced by lateral stiffness of top floor and height-to-span of roof.Vertical load is mainly transferred along arches which are connected by ridge.Compared with point supported roof,internal force of bottom chord bar of diaphragm on whole roof is increased obviously,and lower floor beams have axial force,bearing capacity of roof edge beams should be calculated under double eccentric load.An measure which special shaped column is applied to top layer structure can effectively adjust internal force of roof,and the length of short-leg shear wall which is transformed by special shaped column can use a projected grid length of roof.Although enlarging height-to-span can reduce deflection of roof,the distribution of internal force of roof is significantly affected by height-to-span which should not be less than 1/6.Too large rib stiffness is not significant for improving overall bearing capacity of roof,so height of rib section can be used in 1/40 ~ 1/50 of roof span.Increasing the ridge stiffness has no effect on the overall stiffness of the roof.The closer number of grids,not only can improve the overall stiffness of the roof,but also can reduce the internal forces of the corresponding components.Using the PKPM software to calculate the structure has considered the influence of axial force.The span ratio has remarkable effect on the lower part of the frame beam axial force.Under the different Span ratio,the axial force of the frame beam has little effect on its reinforcement area.The natural frequency distribution of the roof point support and the joint work with the substructure is relatively dense.When working together,the roof should not be simplified as the ideal point support for seismic design.The roof span ratio has little effect on the first three frequencies of the whole structure.Improving the lateral stiffness of the top layer is helpful to increase the overall stiffness of the structure.Increasing the height to thickness ratio of the column,in addition to the flat structure rigidity,can improve the overall structure of arch and torsional stiffness.When increasing the rib stiffness,the stiffness of the whole structure is still mainly controlled by the stiffness of the lower structure.At the same time the section can be determined according to the low height-to-span under the load bearing capacity requirement.The rigidity of ridge is similar to the arch rib of roof that will not affect the overall stiffness of the structure.Under the condition that the dimension of the rib section is invariable,the stiffness of the whole structure isweakened by the closer mesh density.