Collapse-Resistant Performance of Long-Span Single-Layer Spatial Grid Structures Subjected to Equivalent Sudden Joint Loads

Abstract

A dynamic experiment of progressive collapse constitutes the basis of a collapse-resistant analysis. To achieve broad applicability and avoid superfluous influencing factors, two representative substructures extracted from long-span single-layer spatial grid structures were tested using a quick-loading system. The strain and displacement results of the specimens were analyzed, as well as the collapse-resistant mechanisms. The dynamic performance of a full-scale Kiewitt dome was investigated using the hybrid finite-element (FE) model. Finally, a novel cable-reinforced Kiewitt dome is proposed to improve the collapse resistance of Kiewitt domes. The results show that the tests and associated analyses contribute to establishing a database of benchmark models for collapse-resisting simulation of long-span single-layer spatial grid structures. The FE results are well-validated by the test results. The time history of the loading with a suddenly applied load of 1,000 kg for S-10 is similar to the time history of the resistance in a compression mechanism. Owing to the geometric nonlinearity, the time history of the resistance for the catenary mechanism is asymmetrically distributed based on the final equilibrium state. The dynamic performance of long-span single-layer spatial grid structures is significantly affected by the duration of the suddenly applied load. The maximum displacement of the novel cable-reinforced Kiewitt dome is substantially reduced, and the maximum stress is smaller than the yield stress of steel. The superiority of the cable-reinforced Kiewitt dome is therefore demonstrated.