Optimization Analysis of Rotating Cuplok Scaffolding System in the Capping Process of an Ultra-Large Diameter Coal Silo: A Critical Review

Abstract

The construction of ultra-large diameter coal silos presents formidable engineering challenges, particularly during the capping phase, when temporary support structures must span vast distances within constrained, enclosed cylindrical environments. The rotating Cuplok scaffolding system has emerged as an efficient and cost-effective solution to this challenge, enabling the progressive, rotational assembly of silo cap structures without the prohibitive material and labour demands of full-coverage falsework. This critical review synthesises the current state of knowledge across three interconnected domains: the structural mechanics and optimisation of Cuplok modular scaffolding systems; the design requirements and construction constraints of ultra-large diameter silos; and the safety and risk management frameworks applicable to complex temporary structures. Literature searches were conducted across the following bibliographic databases: Web of Science, Scopus, Google Scholar, PubMed (for ergonomic and occupational health dimensions), Engineering Village (Compendex), CNKI (China National Knowledge Infrastructure, for Chinese-language technical literature), J-STAGE (for Japanese-language engineering research), DOAJ (Directory of Open Access Journals), and the structural engineering repository of the ASCE Library. Drawing upon recent peer-reviewed literature spanning structural engineering, construction technology, and safety science, the review identifies principal load-bearing mechanisms, stability-governing parameters, and optimisation strategies relevant to rotating scaffolding configurations. Key findings indicate that second-order geometric non-linearity, joint semi-rigidity, and dynamic load redistribution during rotation are the critical factors determining structural performance. Construction safety is identified as a major concern during non-working transition phases, particularly when the platform is being repositioned between sectors. The review further identifies significant gaps in the literature regarding the specific interaction between rotational kinematics and scaffold structural stability, and calls for more dedicated experimental and computational investigation into this construction scenario. Recommendations are offered for both structural design practice and future research directions, including reliability-based optimisation, integrated digital monitoring, and system-level advanced analysis approaches.