Large-span Structures Research Articles

A complete environmental wind tunnel for studying the evolution of snow accumulations under the effects of wind, rain, and heat

Given the escalating frequency of extreme cold weather worldwide, snow-induced building failures have increased substantially, especially in large-span space structures. The reason for engineering accidents lies in a lack of understanding of the intricate process of the mechanism of full-period evolution of snow “accumulation-melt-crystallization- accumulation” under the coupling actions of wind, rain, and heat. It is significant to develop a comprehensive and accurate environmental wind tunnel for conducting snow-relevant experiments under the multi-factors, which are barely studied. Hence, this paper proposes and establishes an experimental system called “Simulator of Natural Action of Wind-Rain-Heat-Snow for Space Structures (SNOW).” The system consists of an atmospheric boundary layer cryogenic wind tunnel subsystem, snowfall simulation subsystem, rain simulation subsystem, solar and building heating simulation subsystem, and high-precision multi-task monitoring and control subsystem. The facility can provide a 0–20 m/s stable wind field, −15 °C–0 °C low-temperature conditions, and a 2 m × 2 m experimental section. The calibrations of each subsystem were conducted in SNOW to ensure each component can successfully provide basic conditions for snow-relevant experiments. The SNOW can accurately simulate the entire process of natural snowfall and snow evolution under the coupling effects of wind, rain, and heat.

Enhancing the aerodynamic performance of large-span roof using a ‘breathable’ optimization tube: A parametric study

In wind engineering community, large-span roofs are widely acknowledged to be wind-sensitive, and oftentimes aerodynamic optimization is needed to enhance its wind-resistance. For such purpose, we proposed a “breathable” aerodynamic optimization tube in this study, the performance of which was experimentally examined via a series of wind tunnel tests. The results showed that, the proposed aerodynamic optimization tube is capable to significantly reducing the wind loads on the large-span roof, the effectiveness of which varies with different tube parameters. On this account, the effect of six key parameters, namely section shape, inlet-outlet angle, hole size, in-out ratio, hole distance and inlet hole length were examined independently. Overall, the outcomes are expected to provide important implications regarding the wind-resistance design of large-span roof structures.

Simplified calculation method of non-Gaussian wind pressure peak factor for large-span spatial roof structures

Based on the wind tunnel test data of a long-span spatial roof structure, the correlation between higher-order statistics and peak factors was obtained according to the time and frequency domain characteristics of wind pressure-time history, as well as the coincidence condition between wind pressure power spectra of measurement points and wind speed power spectra. A simplified peak factor calculation formula was proposed based on the moment-based Hermite polynomial model. The Gaussian part of the peak factor was calculated through the wind speed spectrum based on the zero-crossing theory, and the parameters related to higher-order statistics were considered as the non-Gaussian part of the peak factor. The simplified method was verified through the instantaneous extreme value method based on a coal shed structure with available long-term wind pressure-time history. It revealed that the results of the proposed simplified method correlate well with that of the instantaneous extreme value method, indicating its accuracy and potential value for engineering practice.

Seismic response control of large-span suspend-dome structures using multidimensional isolation systems

Three isolation strategies have been developed for seismic response control of suspend-domes: bidirectional isolation, bidirectional isolation with additional restrainers, and three-dimensional (3D) isolation. The first and second control strategies use pendulum sliding isolation bearings (PSIBs) and shape memory alloy (SMA)-restrained PSIBs (SPSIBs), respectively, as high-position bearings to support the roof of a structure. The third strategy uses of prepressed spring bearings with additional dampers and SPSIBs with slack SMA strands to form a vertical isolation layer at the roof support and a horizontal isolation layer at the base of the substructure. This paper describes the configurations, working mechanisms, and numerical simulations of these isolation systems in detail and presents their parameter design based on the related design objectives of a prototype suspend-dome structure. In this study, an extensive numerical modeling investigation was performed on isolated and non-isolated suspend-domes to examine the feasibility and effectiveness of the seismic control systems. The results showed that the segmental 3D isolation system provides superior seismic protection performance for the target suspend-dome compared with the bidirectional isolation systems, although the former involves a complex design, modeling, and construction.

Experimental investigation on flexural performance of steel-UHPC composite beams with steel shear keys

Test results of steel-ultra high performance concrete (UHPC) composite beams with welded steel shear keys (SSKs) under four-point bending are presented in this paper. The objective of the investigation is to reduce the self-weight and manufacturing cost of large-span structures. The study investigates the effects of strength of concrete slab, type, spacing and size of SSK, and concrete slab height and width on flexural behavior of composite beams. The experimental results demonstrate that enhancing concrete strength, reducing SSK spacing, increasing concrete slab size, and using large-size SSK can all significantly enhance the flexural performance. The composite beams with welded SSK exhibit a maximum relative slip of less than 4 mm, while the counterpart with welded bolts has a maximum relative slip greater than 4 mm. The study shows that the welded SSK is more effective than welded bolts in improving the interface shear performance of composite beams and improving the stiffness and load capacity. Additionally, the study defines four failure modes of steel-UHPC composite beams, and the formulae for flexural capacity is developed based on the reasonable basic assumptions. The calculated results fit well with the tested results. The research findings can be provided as a technical support for the design and application of steel-UHPC composite beams.

Solar radiation visibility testing algorithm for precise shadow distribution for spatial steel structural thermal analysis under sunlight

As a large-span spatial steel structure, the radio telescope, characterized by its extensive span and numerous structural components, is sensitive to temperature gradients and susceptible to localized deformations induced by non-uniform temperature filed under sunlight, thereby affecting the operational performance. In order to calculate the shadow distribution of the structure, this study proposes a solar radiation visibility testing algorithm based on the depth buffer. To validate the accuracy of the proposed algorithm, the shadow distribution of a shading device is calculated employing the new algorithm, theoretical methods, and Ladybug tools. The results show that the shadow distribution obtained by the three methods is consistent. The thermal numerical simulation of the grid structure using the direct solar radiation calculated by the proposed algorithm is compared with the experiment results, and the error is below 5 %. Taking a radio telescope as an engineering application, the temperature distribution and pointing accuracy under solar are calculated. 9:00 and 16:00 have the worst pointing accuracy, while 11:00–13:00 has the best pointing accuracy. This study can provide a reference for the calculation of temperature field of spatial steel structure which is sensitive to sunlight temperature.

Performance analysis and application fields of reactive powder concrete

Reactive Powder Concrete (RPC) is a novel concrete material prepared from highly active composite admixtures, cement, fine sand, and micro steel fibers through appropriate curing and processing techniques. RPC not only exhibits ultra-high strength and durability but also demonstrates outstanding toughness, good volume stability, and excellent environmental performance. Its use can reduce the demand for natural resources, extend the service life of structures, and reduce waste generation, aligning with the direction of sustainable development and green building. This makes it an ideal choice for constructing large-span lightweight structures and structures operating in harsh environmental conditions, attracting extensive research attention in the international engineering materials field. In summary, RPC, as a new type of concrete material, has broad application prospects in the construction field. With continuous research and technological development, RPC will undoubtedly bring more innovations and new solutions to the construction industry, promoting its continuous progress and development.

Shaking Table Tests and Numerical Analysis Conducted on an Aluminum Alloy Single-Layer Spherical Reticulated Shell with Fully Welded Connections

Aluminum alloy offers the advantages of being lightweight, high in strength, corrosion-resistant, and easy to process. It has a promising application prospect in large-span space structures, with its primary application form being single-layer reticulated shells. In this study, shaking table tests were conducted on a 1/25 scale aluminum alloy single-layer spherical reticulated shell structure. A finite element (FE) model of the reticulated shell structure was established in Ansys. Compared with the experimental results, the deviation in natural frequency, acceleration amplitude, and displacement amplitude was less than 20%, confirming the validity of the model. An extensive analysis of the various rise–span ratios and connection constraints of a single-layer spherical reticulated shell structure was carried out using the proposed FE model. The experimental and simulation results showed that as the rise–span ratio of the aluminum alloy reticulated shell increases, the natural frequency of the reticulated shell structure also increases while the dynamic performance decreases. The connection of the circumferential members changes from a rigid connection to a hinged connection. The natural frequency of the reticulated shell structure is reduced by about 40% while the acceleration and displacement response values are decreased by approximately 15%.

The impact of different length hooked‐end fibers on the structural performance of RC folded plates

AbstractIn this article, the effect of hooked‐end fibers with different lengths on the structural performance of RC‐FPs fabricated from hybrid fiber‐reinforced self‐compacting concrete (HFR‐SCC) was investigated. For this purpose, a total of 15 full‐scale test samples having different plate thicknesses (60, 70, and 80 mm) were produced and tested under bending after a 90‐day curing period. Subsequently, load‐carrying capacity (Pp), flexural toughness (Fth), and deflection ductility index (μu) of all RC‐FPs were found using load‐deflection curves obtained from bending tests, while crack patterns were drawn from the samples tested. Besides, high‐precision contour plots are proposed to estimate the structural performance values of RC‐FPs depending on plate thickness and fiber reinforcing index. As a result, the best structural performance in RC‐FPs was obtained from the use of a longer hooked‐end steel fiber together with micro steel fiber as a hybrid, followed by the lower length hooked‐end steel fibers as singles. Specifically, irrespective of the plate thickness, the hybrid use of longer hooked steel fibers in combination with micro fibers increased the Pp, Fth, and μu values of RC‐FPs on average 1.67, 1.76, and 1.57 times, respectively, compared to the control specimens. As for when using the lower length hooked‐end fiber as single, the values of Pp, Fth, and μu increased on average 1.57, 1.69, and 1.30 times. Lastly, whereas plate thickness has little effect on improving the structural performance of thin‐walled carrier elements such as RC‐FPs, adding fibers in different lengths, aspect ratios, and combinations is much more effective. The collective test results demonstrate that using RC‐FPs made of HFR‐SCC in the roof carrier system of large span structures could improve structural performance, aesthetics, erection time, and earthquake behavior thanks to reduced dead load.

Enhancing large-span structure design and maintenance through the synergy of CAD, BIM, and IoT-AI technologies

The integration of Computer-Aided Design (CAD), Building Information Modeling (BIM), and Internet of Things (IoT) with Artificial Intelligence (AI) represents a transformative shift in the architectural and engineering practices for large-span structures. This paper delves into the quantitative and qualitative enhancements brought about by these technologies, focusing on their pivotal roles in design precision, structural analysis, project management, and maintenance strategies. CAD's evolution from simple drafting to complex 3D modeling has significantly reduced design time and errors, while its integration with structural analysis software has improved load distribution accuracy and material cost efficiency. BIM's contribution to design, construction, and sustainability emphasizes optimized resource allocation and energy-efficient practices. Furthermore, IoT and AI's role in real-time monitoring and predictive maintenance underpins a proactive approach to structural health, ensuring longevity and safety. Through statistical analysis, mathematical modeling, and case studies, this paper highlights the synergistic impact of these technologies on reducing project timelines, enhancing collaboration, and fostering innovation in large-span structure engineering. The findings advocate for a multidisciplinary approach, combining engineering expertise with advanced computational tools to achieve superior outcomes in the construction and maintenance of large-span structures.

Structural monitoring data repair based on a long short-term memory neural network.

As construction technology and project management develop, structural monitoring systems become increasingly important for ensuring large-span spatial structure safety during construction and operation. However, most of the sensors and monitoring equipment in monitoring systems are poorly serviced, resulting in frequent abnormal monitoring data, which directly leads to challenges in data analysis and structural safety assessment. In this paper, a structural response recovery method based on a long short-term memory (LSTM) neural network is proposed by studying the autocorrelation of data and the spatial correlations among data at multiple measurement points. The effectiveness and robustness of the proposed method are verified using the monitored stress data for a grid structure jacking construction process, and the influence of different data loss rates on the recovery accuracy is analysed. The recovery models are compared using a support vector machine and a Multi-Layer Perception (MLP) neural network. The proposed method can effectively restore missing data; notably, the MSE index is 0.6, and the MAPE is below 15%. The data restoration method based on the LSTM neural network is more accurate than the traditional method. Finally, the repair applicability of various types of monitored data is verified using the monitoring data from Hall F of Qingdao Jiao-dong International Airport under typhoon conditions.

ЭКСПЛУАТАЦИЯ СТАЛЬНЫХ ПОКРЫТИЙ УНИКАЛЬНЫХ СООРУЖЕНИЙ.

Currently, employees of the Laboratory for Standardization, Reconstruction and Monitoring of Unique Buildings and Structures of the Department of Metal Structures of the V.A. Kucherenko Central Research Institute are preparing to print the standard of the organization STO 36554501-073-2023 “Technical operation of steel structures for coatings of unique buildings and Structures” in accordance with Federal Law No. 162-FZ dated June 29, 2015 “On Standardization in the Russian Federation Federation”. This SRT 36554501-073-2023 is compiled taking into account the requirements of Federal Laws: dated December 27, 2002 No. 184-FZ “On Technical Regulation”; No. 123-FZ dated June 22, 2008 “Technical Regulations on Fire Safety Requirements” and No. 384-FZ dated December 30, 2009 “Technical Regulations on the Safety of Buildings and Structures”. SRT 36554501-073-2023 applies to steel structures of unique coatings, including including large-span buildings and structures for maintenance, ensuring the safe functioning of buildings and structures. The standard provides an explanation of the concept of “unique buildings and structures”: these include buildings and structures with a height exceeding 100 m, or with a span of more than 100 m, or with a console departure of more than 20 m, or, if the depth of the underground part, relative to the planning mark of the ground, is more than 15 m, or structures where structures and structural schemes are used with the use of non-standard or specially developed calculation methods, or requiring verification on physical models, as well as sports and entertainment, religious buildings, exhibition pavilions, public buildings, shopping and entertainment complexes with an estimated stay of more than 1,000 people inside or more than 10,000 people near the facility. The article presents the materials that served as the basis for the creation of a service station for the operation of steel structures in the coatings of unique structures.

Influence of Prestress on Vibration Frequency of Beam String Structures Based on Exact Matrix Stiffness Method

Beam string structures (BSS) are frequently employed in large-span spatial structures due to their high load-carrying efficiency and elegant appearance. Owing to the neglect of the influence of prestress, the natural frequency of the BSS is often overestimated which could be crucial to the dynamic behavior of BSS. This paper presents an exact matrix stiffness analysis method (MSM) for investigating the relationship between prestress and the natural frequency of the planar BSS. A novel dynamic stiffness matrix of beam–columns considering the natural frequency and axial force is used to develop the MSM. The dynamic analysis of the structural vibration stability of BSS is performed by using the global structural stiffness matrix which is assembled from the element stiffness matrices in the global coordinate system. The proposed MSM with the exact dynamic element stiffness matrix for the dynamic analysis of the BSS is verified by comparing with previous results based on the finite element method. The illustrative examples demonstrate that the prestress in the cable has a negative effect on the natural frequency of the BSS and should be considered in the dynamic analysis. As the axial force increases from zero to the buckling load [Formula: see text], the natural frequency of the BSS decreases from the maximum vibration frequency to zero. The influence of prestress on the vibration frequencies of BSS is particularly significant when the prestress to balance the loads is large, especially in the case of large dead and live loads (e.g. floor slabs).

Dynamic Response Study of Space Large-Span Structure under Stochastic Crowd-Loading Excitation

With the development of civil engineering, lightweight and high-strength materials, as well as large-span, low-frequency structural systems, are increasingly used. However, its self-oscillation frequency is often close to the stride frequency of pedestrians, which is easily affected by human activities. To study the effect of human activities on the dynamic response of structures, it is crucial to choose an appropriate anthropogenic load model. Considering the inter-subject and intra-subject variability of pedestrian walking parameters and induced forces in a crowd, we introduce the interaction rules between pedestrians based on the floor field cellular automata (FFCA). A stochastic crowd-loading model coupling walking parameters, induced forces between pedestrians, and induced forces between pedestrians and structures is proposed for simulating crowd-walking loads. The feasibility of the model is verified by comparing the measured response of a space large-span structure with the predicted response of the proposed stochastic crowd-loading model. The comfort level of the structure under different crowd densities was also evaluated based on the model. It was found that both random combinations of walking parameters and dynamic behaviors of pedestrians can cause significant differences in the structural response. Therefore, the crowd-loading model should consider the influence of pedestrian behavioral factors on the structural response.

Seismic Assessment of Large-Span Spatial Structures Considering Soil–Structure Interaction (SSI): A State-of-the-Art Review

Soil–structure interaction (SSI), which characterizes the dynamic interaction between a structure and its surrounding soil, is of great significance to the seismic assessment of structures. Past research endeavors have undertaken analytical, numerical, and experimental studies to gain a thorough understanding of the influences of SSI on the seismic responses of a wide array of structures, including but not limited to nuclear power plants, frame structures, bridges, and spatial structures. Thereinto, large-span spatial structures generally have much more complex configurations, and the influences of SSI may be more pronounced. To this end, this paper aims to provide a state-of-the-art review of the SSI in the seismic assessment of large-span spatial structures. It begins with the modelling of soil medium, followed by the research progress of SSI in terms of numerical simulations and experiments. Subsequently, the focus shifts towards high-lighting advancements in understanding the seismic responses of large-span spatial structures considering SSI. Finally, some discussions are made on the unresolved problems and the possible topics for future studies.

Shear Performance of Demountable High-Strength Bolted Connectors: An Experimental and Numerical Study Based on Reverse Push-Out Tests

Steel–concrete composite beams, essential for large-span structures, benefit from connectors that reduce cracking at the supports. The crack resistance and alignment with sustainable building trends of high-strength bolted connectors have been extensively researched. Nevertheless, only a few studies exist on their load–slip behavior in hogging sections. In this study, the shear performance of high-strength bolted connectors subjected to tension due to hogging moments was studied based on experiments and numerical modeling according to numerous reverse push-out tests. The results revealed that tensile and splitting cracks were produced in the concrete. Their distribution was affected primarily by the concrete strength and bolt diameter; this distribution became denser at decreasing concrete strengths and increasing bolt diameters. Subsequently, an analysis of the out-of-plane displacement and load–slip response was performed to investigate the phenomenon of anchor rod sliding. A cost-effective and time-efficient finite-element (FE) model was developed to investigate the internal microstates of the specimens. It revealed a correlation between bolt cracking, specimen hardening, steel yield, and failure. A correction factor is also proposed for the shear capacity of bolts within concrete subjected to tension. The findings offer insights into the load–slip response of high-strength bolted connectors subjected to hogging moments, aiding in safer, more durable supports for steel–concrete composite beams.

Assessment of Large Span Multistory Building Using Various Slab Under Earthquake Response

With the growing need for multistory buildings in a variety of industries, the need for novel structural solutions has become critical. This research looks at the structural behaviour of wide span structures, with an emphasis on the use of various slab forms to meet the problems provided by growing architectural trends. The study undertakes a detailed literature analysis, looking into the use of Grid Slabs, Flat Slabs, Waffle Slabs, and Ribbed Slabs alongside regular slabs to improve stiffness and load-carrying capability in large-span buildings. Architects are challenged to accommodate bigger spans while minimising the number of columns, which has led to the introduction of novel slab layouts. Grid Slabs, which have unique grid patterns, and well-established Flat Slabs are popular alternatives. The analysis of the literature reveals an increasing trend among academics who have effectively used various slab designs to meet the issues given by long spans. The findings provide architects, structural engineers, and construction industry stakeholders significant insights into the performance features and advantages associated with each slab type. This study adds to the continuing discussion about optimising structural designs for large-span structures to meet the changing demands of current construction practises. The complete analysis is a helpful resource for professionals involved in multistory building design and construction, assisting in informed decision-making and supporting developments in the field.

Optimizing fatigue life prediction of high strength bolts in bolted spherical joints

Bolted spherical joints (BSJs) are integral to large-span space grid structures commonly used in expansive public and industrial buildings. BSJs are susceptible to fatigue damage in high strength bolts due to variable random loads. This study summarized findings from prior fatigue tests, detailing the fatigue failure patterns and S–N curves for grade 10.9 M20, M30 high strength bolts, and grade 9.8 M39 high strength bolts in BSJs. By employing finite element analysis, the study determined the stress concentration factors for these bolts, which were then utilized in fatigue life estimations using the Heywood model and the local strain approach (LSA). Both methods could yield satisfactory predictions, but when it came to the Heywood model, particularly when modifying it in areas of high stress, it demonstrated superior accuracy in predicting the performance of M20, M30, and M39 high strength bolts. Additionally, incorporating initial defect considerations, fatigue life was predicted using the damage tolerance design method (DTDM). Finally, when comparing the fatigue life prediction results obtained from various methods, it became evident that the modified Heywood model outperformed the other methods. This not only provided a superior solution but also demonstrated user-friendliness, thereby establishing itself as the preferred option for predicting the lifespan of high strength bolts in BSJs.

Application of Response Surface-Corrected Finite Element Model and Bayesian Neural Networks to Predict the Dynamic Response of Forth Road Bridges under Strong Winds.

With the rapid development of big data, the Internet of Things (IoT), and other technological advancements, digital twin (DT) technology is increasingly being applied to the field of bridge structural health monitoring. Achieving the precise implementation of DT relies significantly on a dual-drive approach, combining the influence of both physical model-driven and data-driven methodologies. In this paper, two methods are proposed to predict the displacement and dynamic response of structures under strong winds, namely, a Bayesian Neural Network (BNN) model based on Bayesian inference and a finite element model (FEM) method modified based on genetic algorithms (GAs) and multi-objective optimization (MOO) using response surface methodology (RSM). The characteristics of these approaches in predicting the dynamic response of large-span bridges are explored, and a comparative analysis is conducted to evaluate their differences in computational accuracy, efficiency, model complexity, interpretability, and comprehensiveness. The characteristics of the two methods were evaluated using data collected on the Forth Road Bridge (FRB) as an example under unusual weather conditions with strong wind action. This work proposes a dual-driven approach, integrating machine learning and FEM with GNSS and Earth Observation for Structural Health Monitoring (GeoSHM), to bridge the gap in the limited application of dual-driven methods primarily applied for small- and medium-sized bridges to large-span bridge structures. The research results show that the BNN model achieved higher R2 values for predicting the Y and Z displacements (0.9073 and 0.7969, respectively) compared to the FEM model (0.6167 and 0.6283). The BNN model exhibited significantly faster computation, taking only 20 s, while the FEM model required 5 h. However, the physical model provided higher interpretability and the ability to predict the dynamic response of the entire structure. These findings help to promote the further integration of these two approaches to obtain an accurate and comprehensive dual-driven approach for predicting the structural dynamic response of large-span bridge structures affected by strong wind loading.

Thermo-structural analysis and design for multi-functional membrane roofs of airport terminals

The utilization of large-span membrane structures in airport terminals has attracted considerable attention due to their excellent building aesthetics, reasonable structural behavior and multi-functional applications. Integrating structure and function is useful to improve thermal performance of such buildings. This study focuses on a scaled two-layer membrane roof in accordance with a newly-built aerogel-membrane airport roof and investigates the dynamic building thermal performance. The two-layer membrane roof is composed of an outer membrane layer as structural element, an air gap for ventilation and an inner membrane layer integrating aerogel mats. The effects of aerogel thickness, ventilation velocity and gap height are analyzed with multi-physics numerical tools. The structural behavior of the aerogel-membrane roof structure is examined in agreement with the building standards. The comparison between numerical and experimental results on solar irradiance is performed to demonstrate the reliability of numerical results under the typical environmental conditions. The thickness of the aerogel layer and the ventilation velocity are shown to have a significant effect while the air-gap height plays a minor role. A maximum temperature reduction of 4.7 °C demonstrates that using the proposed approach can improve building thermal performance. Moreover, temperature curves with small fluctuations indicate an efficient control of the indoor temperature. Therefore, the thermo-structural analysis method of the multi-functional membrane roofs can guarantee structural safety and facilitate building thermal performance control.