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The application of high-strength steel in extremely cold polar regions can reduce steel consumption and save the cost of fabrication, transportation, and installation of steel structures in the harsh low-temperature environment. In order to study the mechanical properties of HG785 high-strength steel under polar low-temperature conditions, uniaxial tensile tests were conducted on high-strength steel coupons by considering two thicknesses and five low-temperature cases. It was found that the elastic modulus, yield strength, and ultimate tensile strength of HG785 high-strength steel in polar low-temperature environment are higher than those at an ambient temperature of 25 ℃. All tensile coupon specimens failed by traditional necking in a ductile manner without brittle failure tendency. Based on the test results, accurate prediction models for mechanical properties of HG785 high-strength steel in polar low-temperature environment were established by the best subset regression analysis. This will facilitate the application of high-strength steel in the design of structural members, joints, and systems in an efficient manner, and provide theoretical support for the promotion of high-strength steel structures in polar low-temperature regions.

This paper investigates the ultimate capacities of domestic cold-formed stainless steel square and rectangular hollow sections (SHS and RHS) undergoing web crippling. The finite element (FE) software Abaqus was employed during the investigation. It verifies the validity of FE models against experimental results available in the literature and performs an extensive parametric study comprised of 224 FE analyses to obtain the web crippling capacities of cold-formed stainless steel SHS and RHS, considering various materials, cross-sectional dimensions, bearing lengths and loading conditions in the parametric study. Based on the obtained FE results, the applicability of existing web crippling design provisions to domestic cold-formed stainless steel SHS and RHS is evaluated. The results indicate that the technical code of cold-formed steel structures (exposure draft) cannot be used for the studied cold-formed stainless steel SHS and RHS. On the other hand, it is shown that the American Specification SEI/ASCE 8-22 and proposed direct strength method (DSM) can lead to safe and accurate design predictions. Therefore, the SEI/ASCE 8-22 and DSM can be used to predict the capacities of domestic cold-formed stainless steel SHS and RHS undergoing web crippling.

Integral steel platform formwork is widely used in the construction of super high-rise buildings, which brings a high degree of risk uncertainty to construction personnel. Therefore, it is crucial and necessary to establish a risk-based evacuation model for steel platform formwork in skyscraper construction. First, the spatial distribution of hazards sources on the steel platform is considered, hazardous areas are defined, and expert data are collected through survey questionnaires to assess the joint risk probability. Next, the joint risk probability of hazardous areas is coupled into the evacuation process based on the cellular automaton floor field model, and the evacuation process of construction personnel on the steel platform is simulated. Finally, the proposed risk-based evacuation simulation model is applied to an actual construction project. The results show that the influence of the top and lower hazardous areas on the evacuation process is significantly affected by the size of the exit. The model provides a new paradigm for experience-oriented construction safety management, with a theoretical and application value for the maintenance of the integral steel platform formwork system.

In the construction industry, the combination of Industry Foundation Classes (IFC) and semantic web technologies emerges as a promising approach for project information management. However, semantic web technologies are unfamiliar to construction industry practitioners, and there is an absence of useable tools to automate semantic web-based create, read, update, and delete (CRUD) operations on Building Information Modeling (BIM) data. Moreover, the query results from some SPARQL Protocol and RDF Query Language (SPARQL)-based information retrieval methods typically cannot be postprocessed. To overcome these issues, this paper initially proposes a browser/server (B/S) architecture platform prototype to mitigate the operational complexity of the developed system. Subsequently, the core submodules of this platform prototype are developed via Apache Jena and Java Database Connectivity (JDBC) APIs, thereby supporting automatic CRUD operations and result-analyzable SPARQL queries. Furthermore, by leveraging the developed CRUD systems, we propose a feasible method for implementing the soft-coded Shapes Constraint Language (SHACL)-based validation with variable thresholds, and subsequently develop an information compliance checking service for weld size. Eventually, the effectiveness of the developed CRUD system functions and the compliance checking service is validated by conducting case tests. In short, this study proposes a viable approach for the automatic execution of semantic web-based CRUD operations and constraint validation on Resource Description Framework (RDF)-represented information converted from the IFC model. This work contributes to the application of IFC and semantic web technologies within construction project management. [ABSTRACT FROM AUTHOR]