Static properties and stability of segmentally prestressed cylindrical reticulated mega-structures

摘要

A new type of segmentally prestressed cylindrical reticulated mega-structure is proposed. The mechanism and detailed layout of the segmental cable-strut system are presented. The static properties and stability of the structure are analyzed and compared with those of the structure without cable-strut system. The reasonable ranges of key arrangement parameters for the segmental cable-strut system are obtained, including the rise-to-span ratio, length and distribution of the strut, and pretension degree and distribution of the cable. In addition, the effects of member buckling on the global stability of the structure and its propagation rule are investigated. On this basis, the substitution of buckling-resistant members for buckling members is proposed, and the improvement effect on the global structural stability is further discussed. The results indicate that the introduction of the segmental cable-strut system can effectively improve the static properties and stability of the reticulated mega-structure. Member buckling has a significant adverse effect on the global structural stability, and thus their interaction should be considered in the stability analysis of the structure. Member buckling initially occurs in the lower chord members near the supports in the middle of the structure, and subsequently propagates to both ends of the structure along the longitudinal direction and toward the supports along the transverse direction at the same time. Additionally, substituting buckling-resistant members for the lower chord members within about 1/6 of the arc length of each latticed arch close to supports is an effective measure for improving global stability.