Analysis On Resistance To Progressive Collapse Of Single-layer Cylindrical Lattice Shell

Recently, terrorist attacks and other accidental factors have caused many structure progressive collapse accidents. The design and analysis of the progressive-collapse resistance therefore attracts more and more attention, and it becomes a hot issue in engineer. The structures in engineering are complex with various styles, and almost all structures have the risk of progressive collapse while a lot of problems still need prompt solution. Therefore, conducting the analysis of the progressive-collapse resistance is not only has great significance in engineering but also sets the theoretical basis for the formulation of related codes.Lattice shell structure is a major structure at present, in this study a single-layer reticular shell structure, one of the most common structure types, is adopted to investigate its ability of the progressive-collapse resistance, the major work is as follows:(1) Some progressive-collapse events around the world are firstly introduced, followed by a literature review on the study of the progressive-collapse resistance, and the specifications about the design and analysis on the progressive-collapse resistance in codes.(2) In order to determine the sensitivity value of the links and find out the key links, the dual nonlinear static response of the structure was analyzed based on the method of sensitivity analysis with conceptual judgement. Moreover, the effects of height-span radios, length-width ratio and cross sections of the link on the sensitivity of the key links were investigated.(3) The performance of the single-layer reticular shell structure resistance of progressive collapse under the state of serviceability was evaluated using the alternate path method. The analysis process of the shell collapse considering the condition that member buckling was established, then the progressive-collapse procedure of the single-layer shell structure and the failure order of the links were studied and the effects of the residual capacity of compressed members and the node domain on the anticollapse ability of the shell structure were analyzed.(4) Finally, the effects of the strengthened cross section of the link sections in local area and the additional spatial truss in the middle region of the shell structure on the capability of the structure resistance of progressive collapse were explored emphatically, and it is necessary to pay attention to preventing the accidental events and some conceptual suggestions are proposed.