Summary
Prefabricated steel structures have certain obvious advantages, that is, rapid construction, industrial production, and environmental protection. Although prefabricated structures have been ...applied in a number of countries in the world, in most cases, these structures are suitable only for low‐rise buildings, and their applications in high‐rise buildings are nota\bly rare. This paper proposes a new type of prefabricated steel structure called the modular‐prefabricated high‐rise steel frame structure with diagonal braces. Based on the T30 building, which is a hotel building with 30 storeys above the ground, the mechanical properties, failure mode, failure mechanism, and elastic–plastic development laws of the structure were studied via elastic and elastic–plastic design and analyses under various load cases and combinations. The analysis of the internal force and displacement response with frequent earthquakes was performed using the response spectrum and elastic time‐history methods, and an analysis under rare earthquakes is performed via static elastic–plastic pushover analysis. This paper summarizes the elastic and elastic–plastic structural design methods and process. This study provides important references for the design of this kind of modular‐prefabricated high‐rise steel structure, and the design method has been compiled into a design specification named Technical Specifications for Prefabricated Steel Frame Structure with Diagonal Bracing Joints.
•An innovative self-centering (SC) modular steel structure (MSS) connection is proposed.•Seismic behaviors of MSS and SC-MSS connections are investigated due to cyclic loadings.•SC-MSS connection ...exhibits better bearing capacity and self-centering capability.•SC haunch braces can reduce the plastic damage and improve the ductility of connection.
As an efficient and environment-friendly technique that combines off-site manufacturing of modules and on-site assembly, modular buildings have been adopted in many areas of the construction industry. This paper proposes an innovative modular steel structure (MSS) connection with bolted cover plates, which inserts a cross-shaped plug-in connector inside the adjacent columns to achieve accurate positioning in the module installation and provide partial shear capacity. A seismic retrofit method using hinged diagonal self-centering (SC) haunch braces is proposed for the MSS connection to improve the seismic performance and achieve functional recoverability after earthquakes. Hysteretic behaviors of the MSS connection and the self-centering MSS (SC-MSS) connection are investigated due to cyclic loadings. Results demonstrate that compared with the MSS connection, the SC-MSS connection is expected to improves strength and stiffness and exhibits stable flag-shaped hysteretic responses with a satisfactory self-centering capability. The hinged diagonal SC haunch braces are capable of reducing the average stress level around the connection core region, controlling the development of plastic damage, avoiding the local failure, and improving the ductility of connection. The present study provides practical connections and important guidance for the applications of modular steel structures in the medium- and high-intensity seismic regions.
We review of the state of the art in probabilistic modelling for fatigue reliability of civil engineering and offshore structures. The modelling of randomness and uncertainty in fatigue resistance ...and fatigue load variables are presented in some detail. This is followed by a review of the specifics of reliability analysis for fatigue limit states and a background on the semi-probabilistic treatment of fatigue safety. We discuss the different life-cycle reliability concepts and give an overview on probabilistic inspection planning. We describe the choices made in the Probabilistic Model Code of the Joint Committee of Structural Safety, present alternatives to these choices and suggest areas of future research.
•The paper reviews fatigue reliability assessment for civil engineering steel structures.•The paper compares different approaches to modelling fatigue reliability, both deterministically and probabilistically.•The paper gives an overview of fatigue load modelling for civil engineering steel structures.•The paper discusses the connection between codified fatigue reliability and different safety philosophies.•The paper summarizes reliability- and risk-based life-cycle management strategies.
Wuhan Leishenshan/Leishenshan (“Leishenshan” for short) hospital is a makeshift emergency hospital for treating patients diagnosed with the novel coronavirus-infected pneumonia (NCIP). Engineering ...construction uses modular composite building finished products to the greatest extent, which reduces the workload of field operations and saves a lot of time. The building information model (BIM) technology assists in design and construction work to meet rapid construction requirements. Besides, based on the unmanned aerial vehicles (UAVs) data analysis and application platform, digitization and intelligence in engineering construction are improved. Simultaneously, on-site construction and overall hoisting were carried out to achieve maximum efficiency. This article aims to take the construction of Leishenshan Hospital as an example to illustrate how to adopt BIM technology and other high-tech technology such as big data, artificial intelligence, drones, and 5G for the fast construction of the fabricated steel structure systems in emergency engineering projects.
•Assembled design, clean and dirty partition, total impermeability;•Modular sealing and anti-diffusion air pressure management unit;•Optimal architecture, development, logistics and process alignment;•BIM, 5G, AI, IoT, among other IT applications;•Cloud supervisors and civic engagement
Recently, attention is being focused on Design for Deconstruction (DfD) as one of the most effective structure end-of-life design scenarios. Although several research efforts have dealt with the DfD ...and reversible buildings design theories for the past few years, the lack of technological support for developing tools to improve DfD to be BIM compliant has been clearly noticed. This research presents a Deconstructability Assessment Scoring (DAS) methodology for quantitative assessment of Steel Structures deconstructability. The proposed methodology takes into consideration a number of steel parameters and their deconstructability. Seven innovative solutions contributing to steel connections deconstructability are considered in the proposed research. Furthermore, steel elements reusable fire-proofing systems are introduced to provide the required fire resistance and deconstructability. The detailed analyses for the selected parameters are adopted and implemented to form the Steel Structure Deconstructability Assessment Scoring (SS-DAS). The proposed methodology is implemented in Autodesk Revit using Dynamo. The proposed innovative solutions are modeled as families to automate the scoring process.
•Present a Deconstructability Assessment Scoring (DAS) methodology for steel structures (SS-DAS)•Provide an accurate index for steel structures deconstructability•A BIM-based framework, using Revit and Dynamo, has been established to automate the index calculations•Demonstrate the significance of using innovative solutions to improve the SS-DAS index•Validate the use of the developed methodology by applying it on a case study of a real steel structure utility building
•Vertical post-tensioned (PT) connection for modular steel buildings is presented.•The connection comprises of a post-tensioned threaded rod and a steel box.•The post-tensioned threaded rod is ...installed inside the hollow steel columns.•The steel box is placed between two vertically consecutive columns.•The PT connection eliminates on-site welding for vertical intermodular connection.•Specimens with PT and welded connection were tested under quasi-static cyclic load.•The behavior of specimens with PT and with welded connection are compared.
Modular construction is an off-site construction technique. In this method, structural volumetric modular components are produced in a factory and assembled on-site to form a larger, permanent building. Typical vertical connections of modular steel buildings (MSBs) are provided by on-site welding. Welding may interfere with the finishing of the modules and also when several modules are placed together at a given floor level complete access for welding is compromised. As an alternative to on-site welding, the present paper proposes a new vertical post-tensioned (PT) connection for MSBs. This connection is comprised of a post-tensioned threaded rod installed inside hollow structural sections (HSS) columns and a steel box placed between two modules. In order to evaluate the general and the seismic performance of the proposed connection, eight quasi-static cyclic loading tests were performed in T-shaped subassemblies. A combination of three different steel boxes and three initial post-tensioning loads levels were considered. Additionally, two quasi-static cyclic loading tests were performed using standard welded connections. No local buckling was observed in any of the specimens and no welding fractures occurred up to 3% drift demand. Results indicated that in comparison to the welded connection the proposed PT connection have similar lateral stiffness and strain distribution, and a higher cumulative energy dissipation capability. Therefore, the proposed connection has the potential to eliminate on-site welding in the assembly of the modules while providing the lateral resistance required.
Summary
The use of modular‐prefabricated steel structures has distinct advantages, such as rapid construction, industrial production, and environmental protection. Although this type of structure has ...been extensively employed around the world, it is primarily used for low‐rise buildings; its application in high‐rise buildings is limited. This paper proposes a new type of modular‐prefabricated high‐rise steel frame structure with diagonal braces. An elastic–plastic time‐history analysis of a 30‐storey building during rare earthquakes was performed. The base shear, storey drift, stress, damage characteristics, and other performances of the structure were investigated. According to the mechanism analysis, finite element simulation, and model test, the formulas for the elastic and elastic–plastic design of the truss–column connection, column–column flange connection, and diagonal brace–truss connection are proposed in this paper. The control parameters for the structural design are also discussed. This study provides an important reference for the research and design of this type of modular‐prefabricated high‐rise steel structure. The design method has been compiled into a design specification named Technical Specifications for Prefabricated Steel Frame Structure with Diagonal Bracing Joints, which is unique for this type of structure.
Steel structures have long been recognized as excellent earthquake-resistant systems. However, this viewpoint wavered after the 1994 Northridge and 1995 Kobe earthquakes, when thousands of steel ...buildings experienced local or global damage making them difficult, if not impossible, to repair. To avoid the inconvenience and costs associated with such damage, significant research has been conducted on approaches that enhance structural resilience. This paper summarizes some of the recent technological advances in the field of seismic resilient steel structures, covering diverse aspects including emerging smart materials, novel members, and innovative design of structural systems. Challenges arising from the incorporation of these new design philosophies are also described and areas for further development are identified. Performance-based design approaches for seismic resilient steel structures are touched upon, and some practical applications that have emerged over the last decade are presented. Instead of giving an exhaustive compilation of all the relevant studies, this paper highlights the authors' unique reflections emphasizing current issues and future needs related to steel buildings. This paper should not only benefit professionals and researchers who have been working in this area for a long time, but it also enlightens a wider audience wishing to become acquainted with the state of the art related to this exciting topic.
•Recent technological advances in seismic resilient steel structures are critically reviewed.•Emerging smart materials, members and structural systems are covered.•Challenges of new design philosophies are described with further research needs identified.•Performance-based design for seismic resilient steel structures is touched upon.•Practical applications that have emerged over the last decade are presented.
•Upgraded Whale Optimization Algorithm (UWOA) is proposed.•Optimal design of fuzzy logic controller is obtained using the proposed method.•The performance of the upgraded method is compared with ...various algorithms.•Nonlinear behavior of the structure is considered in optimization process.
In the case of controlling the seismic vibration of a structure, reliance on human knowledge and expert in the formulation of a fuzzy logic controller leads to non-optimal solutions, which makes the use of control devices and algorithm unreasonable. In most cases, the calculated control force for high-rise buildings is very large and the controlled response of the structure is not significantly decreased. To overcome these drawbacks, the parameter tuning of fuzzy systems with optimization algorithms are necessary. This paper focuses on the optimization of a fuzzy controller applied to a seismically excited nonlinear steel building. In the majority of cases, this problem is formulated based on the structural responses in linear range, however in this paper, objective functions and the performance criteria are considered with respect to the nonlinear responses of the structure. An Upgraded Whale Optimization Algorithm is proposed and utilized as the optimization technique for parameter tuning of the fuzzy controller. The performance of the presented upgraded algorithm is compared with the standard Whale Optimization Algorithm and eight different metaheuristic algorithms. The obtained results prove that the upgraded method is capable of providing competitive results.
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