Progressive Collapse Analysis of Single-Layer Latticed Domes With Fabricated Joints

Progressive collapse accidents of single-layer latticed domes seriously threaten public safety. The progressive collapse-resisting capacity (PCRC) is gradually becoming an essential requirement in the design of spatial structures. Currently, the joint system used in spatial structures can be divided into two categories: welded joints and fabricated joints. The semi-rigidity of fabricated joints may have a significant influence on the PCRC of single- layer latticed domes. In this study, the PCRCs of single-layer fabricated latticed domes with identical span and rise-to-span ratio are evaluated based on the critical progressive collapse load (CPCL). The collapse mechanism of single-layer latticed domes with different grid forms is revealed by progressive analysis. In addition, the effects of joint rigidity, grid form and type of initial failure are further evaluated. The results indicate that the collapse mechanism of single-layer latticed domes includes the radial propagation type and the circumferential propagation type. The latticed domes with quadrilateral grids have much lower PCRC than those with triangular grids. The CPCLs of weld-jointed latticed domes are 5% to 22% higher than those of the fabricated latticed domes with the same grid form. The above influence should be fully considered in the progressive collapse-resisting design of latticed domes with fabricated joints.