| It is a new kind of reticulated shell composed of multi-ribbed flat plates.It can also be understood as a reticulated shell obtained by bidirectional bisection of circular surface,and then replacing the surface with a plane.The structure has the advantages of convenient construction of multi-floor slab,and retains the characteristics of space force of shell.Based on bidirectional folded plate to the concrete flat net shell as the research object,first the finite element theory is adopted to analyze the structural static performance and dynamic characteristics,lay a foundation for subsequent elastic stability and aseismatic analysis,eigenvalue buckling analysis on the elastic stability of the structure performance is analyzed,the vibration mode decomposition spectrum method for seismic response characteristics of the structure are analyzed.In addition,the influence of the parameters such as the ratio of the span to the span,the stiffness of the backbone,the upper chord stiffness of the edge truss,the stiffness of the multi-ribbed beam and the stiffness of the roof plate on the mechanical properties of the structure was considered for parameterization analysis,so as to understand the internal force and deformation law of the structure,and to provide a reference for the practical application of engineering.Concrete two-way folding plate of flat net shell of static and dynamic analysis shows that the structure has good stiffness,the structure of the bending moment distribution of similar ribbed floor,rise-span ratio increase will make structural resistance to deformation ability enhancement,backbone can be seen as an elastic support of ribbed plate,change the bent edge truss height on the overall structure stiffness enhancement effect is not obvious,ribbed beam stiffness change for the overall stiffness is bigger,the roof plate thickness changes mainly affect the structure of axial force,spectrum distribution is relatively dense structure,overall stiffness distribution more uniform.It is suggested that the ratio of vector to span should be 1/6-1/4.The height of the cross section of the backbone is to meet its own bearing capacity.The height of the upper chord section of the edge hollow truss is 1/50-1/35 of the structural span.The cross-section height of the multi-ribbed beam is taken as the structural span 1/120-1/75;The thickness of the roof plate is determined according to the construction requirements.The seismic response of the concrete double-sided folded slab quasi-flat reticulated shell is analyzed by mode decomposition response spectrum method.The results show that the upper chord and backbone of the edge hollow truss are obviously affected by earthquake,and the seismic effect should be considered in the structural design.Increasing the stiffness of the backbone has a greater effect on the seismic internal force coefficient.Increasing the stiffness of the upper chord of the hollow truss has a smaller effect on the seismic internal force coefficient.When changing the stiffness of the multi-ribbed beam,the variation trend of the seismic internal force of the structural members is the same.The analysis of the elastic stability of the concrete bidirectional folded plate quasi-flat reticulated shell shows that the ratio of span to span is the main factor affecting the critical load of elastic stability of the structure.The backbone is the main constraint component on the edge of multi-ribbed slab,and the increase of backbone stiffness has little effect on the critical load of the structure.Changing the height of the upper chord section of the hollow edge truss has little effect on the critical load of the structure.Increasing the stiffness of the multi-ribbed beam is beneficial to enhancing the elastic stability of the structure.Increasing the thickness of roof slab has little effect on the critical load of structure.Over-thick roof slab will increase the dead weight of structure,which is not conducive to strengthening the stability of structure. |
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