City Research Online

Abstract

In this paper, a novel end-plate joint was proposed, which was designed to implement the three-stage control concept against progressive collapse. It delays the collapse process by presetting friction force, special-shaped bolt hole and adding composite cushion at the bottom of bolt hole. The anti-collapse mechanism and control strategy of the structure under the influence of multiple factors were studied by means of beam-column subassembly test and numerical and theoretical analysis. The results show that the initial stiffness of the load-displacement curve of the new bolted joint subassembly is small, but the yield plateau is long and the failure load is large. The curve has obvious three-stage characteristics, and the catenary mechanism is fully developed. That is, the collapse process of the structure was divided into three stages: “small impact”, “medium impact” and “large impact”. On this basis, the corresponding three-stage anti-collapse control strategy was proposed and verified by finite element model. During the “small impact” stage, mainly based on the reasonable initial stiffness requirements, the friction coefficient is changed through the coating of the steel plate, meanwhile the bolt preload is adjusted to determine the preset friction force of the joint, so as to meet the “small impact immovable” requirement. During the “midium impact” stage, the preset extrusion force is mainly determined by changing the ratio of the “jammed diameter” to the bolt diameter based on the reasonable slip distance and the reasonable extrusion force, so as to meet the requirement that the “midium impact stuck”. In the stage of “final impact”, the preset structure's ability to resist progressive collapse is determined by changing the performance of the composite cushion at the bottom of the bolt hole, according to the requirements of reasonable progressive collapse resistance of the structure, so as to realize the requirements of “final impact non-collapse” or delay the process of progressive collapse of the structure. The results of substructure model test and finite element analysis show that the proposed three-stage anti-continuous collapse control strategy was easy to implement, and the mechanism and capacity of anti-continuous collapse were improved obviously, which has a good research and application prospect.

Publication Type:	Article
Additional Information:	© 2025. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
Publisher Keywords:	Bolted end-plate joint, Beam-column substructure, Variable diameter hole, Collapse mechanism, Control strategy
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) T Technology > TH Building construction
Departments:	School of Science & Technology School of Science & Technology > Department of Engineering
SWORD Depositor:	Symplectic Administrator

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