Key Construction Technology Research Articles

Research on key technologies for construction of steel structures in ultra large span cold storage

Taking the 100,000-ton automatic cold storage construction project of Weizhou Investment Holding Co., Ltd. as an example, this thesis systematically analyzes the main difficulties in the construction of super-large-span steel plant in terms of material transportation and handling, large-size components lifting, joints handling and welding, foundation reinforcement, and puts forward corresponding solutions. It not only provides practical suggestions for solving the difficulties in the construction of super-large-span steel structure plant, but also has guiding significance for improving the construction quality and safety management level of the whole industry.

Research on the migration law of aggregate particles in the compaction process of asphalt mixture based on discrete element method

Asphalt mixture compaction is among the key technologies in asphalt pavement construction, but the effect of asphalt mixture mixing quality on mixture compaction performance is still unclear. This research aimed to develop an asphalt mixture compaction model by discrete element simulation and verify it by compaction degree. Asphalt mixture compaction process was simulated and the effect of asphalt mixture workability on the stress, migration law and void distribution properties of aggregate particles during compaction process was investigated. The obtained results showed that the developed asphalt mixture compaction model was reasonable and correct. The more uniform the asphalt mixture is mixed, the smaller the average force on the aggregates, the aggregate particle migration velocity, and the aggregate particle displacement during the compaction of the asphalt mixture. Under the same conditions, increasing the mixing temperature from 140℃ to 180℃ increased the average velocity of the aggregates in the asphalt mixture by 92 %. It also decreased the voids in the compacted mixture specimens. At the same time, under the action of edge effect, void distribution at the center of compacted specimen was small, void distribution around the specimen was high, and void distribution along specimen compaction force direction was also high.

Geological challenges of tunnelling using large slurry shield machine in dense urban centre

Tunnelling in complex geological strata is a challenging task that can affect the performance of shield machines and result in unexpected hazards. Therefore, extensive knowledge of unfavourable environments and shield operational parameters is essential for ensuring successful and safe tunnelling. This study aims to analyse the geological and hydrological conditions of the Chunfeng Tunnel and present the key construction technologies of a large slurry shield machine when crossing complex strata. To this end, attempts were made to (i) discuss the geological and environmental challenges encountered during the tunnelling process and present some early interpretations based on the database information, (ii) analyse the factors affecting tunnel performance and simulate the ground surface settlement along the tunnel alignment and (iii) discuss the countermeasures under adverse ground conditions and propose future directions. The results revealed that tunnelling in fault zones with soft upper and hard lower strata led to severe wear of disc cutters and controlling the tunnelling parameters could provide a suitable method for adjusting the construction process. This study leveraged extensive experience gained during tunnelling using a large slurry shield machine, with special emphasis on mixed ground strata, by providing valuable insights and suggested responses for effective tunnelling strategies.

Digital twin challenges and opportunities for nuclear fuel manufacturing applications

There have been a number of digital twin (DT) frameworks proposed for multiple disciplines in recent years. However, there is a need to develop systematic methodologies to improve our ability to produce DT solutions for the nuclear fuel industry considering specific requirements and conditions exclusive to the nuclear fuel manufacturing cycle. A methodology tailored for nuclear fuel production is presented in this paper. Due to the nature of the chemical processes involved in fuel manufacturing, we highlight the importance of using a combination of physics-based and data-driven modelling. We introduce key technologies for DT construction and the technical challenges for DT are discussed. Furthermore, we depict typical application scenarios, such as key stages of the nuclear manufacturing cycle. Finally, a number of technology issues and research questions related to DT and nuclear fuel manufacturing are identified.

Research on Coal and Gangue Recognition Based on the Improved YOLOv7-Tiny Target Detection Algorithm.

The recognition technology of coal and gangue is one of the key technologies of intelligent mine construction. Aiming at the problems of the low accuracy of coal and gangue recognition models and the difficult recognition of small-target coal and gangue caused by low-illumination and high-dust environments in the coal mine working face, a coal and gangue recognition model based on the improved YOLOv7-tiny target detection algorithm is proposed. This paper proposes three model improvement methods. The coordinate attention mechanism is introduced to improve the feature expression ability of the model. The contextual transformer module is added after the spatial pyramid pooling structure to improve the feature extraction ability of the model. Based on the idea of the weighted bidirectional feature pyramid, the four branch modules in the high-efficiency layer aggregation network are weighted and cascaded to improve the recognition ability of the model for useful features. The experimental results show that the average precision mean of the improved YOLOv7-tiny model is 97.54%, and the FPS is 24.73 f·s-1. Compared with the Faster-RCNN, YOLOv3, YOLOv4, YOLOv4-VGG, YOLOv5s, YOLOv7, and YOLOv7-tiny models, the improved YOLOv7-tiny model has the highest recognition rate and the fastest recognition speed. Finally, the improved YOLOv7-tiny model is verified by field tests in coal mines, which provides an effective technical means for the accurate identification of coal and gangue.

Key Technologies of Intelligence in Network Security Construction and System Development

In today's rapidly developing information technology, people's attention to network security is also constantly increasing. In the context of the new era, in order to better manage, protect, coordinate, and evaluate network resources and information, it is necessary to apply intelligent technology. Starting from the problems existing in the current network security construction and system development, this paper conducts in-depth analysis and research on the application of intelligent key technologies in the network security construction and system development. The results show that intelligent key technologies can improve the confidentiality of the Internet security systems from 91.12% to 95.86%, and the effect is very significant. It is hoped to provide some reference and reference for relevant staff, further improve the efficiency and quality of network security construction and system development, and ensure the safety of the lives and property of the general public.

Key construction technology of super-high fish-belly cable-point folding curtain wall

Key construction technology of super-high fish-belly cable-point folding curtain wall

Key construction technology of stone-like concrete hanging panel curtain wall

Key construction technology of stone-like concrete hanging panel curtain wall

(Invited) Electrocatalytic Reduction of Carbon Dioxide over Aluminum-Added Coppor Oxide Gas Diffusion Electrode

Electrochemical cells are the key technologies for construction of carbon neutral society to produce hydrogen from water and produce useful chemicals from carbon dioxide utilizing renewable energy. Copper species are the unique catalysts for electrochemical carbon dioxide reduction reaction (CO2RR) with capable of producing C2+ products such as ethanol and ethylene. Selective production of target chemical is one of the most important requirements for the catalysts, and addition of different elements and surface modifications have been reported to be beneficial for the selective production.In the present study, copper oxides-based catalysts prepared with electroless plating techniques were examined for electrochemical CO2RR. To conduct CO2RR at relatively high current densities, the catalysts were examined in the form of gas diffusion electrode (GDE). The Cu2O based GDE was prepared by the combination of physical vapor deposition and electroless plating on hydrophobized carbon paper coated with mesoporous carbon layer. After the electroless plating treatment, the metal precursors were successfully converted to core-shell structured electrocatalyst with Cu2O shell and Cu core. By introducing different elements such as aluminum to the precursor, metallic Cu, the different element added catalysts were successfully prepared in the shape of GDE. Addition of different element significantly improved durability of the core-shell structured catalysts and, as a result, faradaic efficiency of ethylene of 24 hours after starting electrolysis was increase from 32% to 47% under applying cathodic current of 260 mAcm-2. Further surface modifications with Nafion enhanced the durability and the faradaic efficiency of ethylene maintained >50% for over 48 hours and reached about 60% in maximum.In the presentation, we will discuss about the detailed structure of the electrocatalysts, results of full-cell test, and longer durability test over 100 hours.

Analysis on the key construction technology of steel structure in prefabricated high-rise building-A case study of Pingshan new energy vehicle industrial park in Shenzhen

Prefabricated steel structures are more energy efficient and adaptable than ordinary structures. The characteristics of prefabricated steel structures can better meet the needs of modern buildings, such as diversification, large space, and high strength. At the same time, it has the advantages of shortening the expected construction period and improving the construction efficiency. In this paper, the plant of Pingshan new energy automobile Industrial Park in Shenzhen is taken as a case to study the key construction technology of steel structure in prefabricated high-rise building. Firstly, the plant of Pingshan new energy automobile Industrial Park in Shenzhen is compared with the ordinary plant, and the advantages and disadvantages of the first "skyscraper" workshop are analyzed. Then, section construction technology of steel structure plant members, high-rise steel structure lifting technology, green building technology are analyzed, respectively. Finally, the prospect and development of prefabricated building are expounded. It is suggested that the prefabricated high-rise building can be used in more architectural designs.

Safety risk analysis of high-rise steel structure building construction

At present, in the construction of high-rise steel structures, many construction companies have inaccurate grasp of the key technologies of steel structure construction, and in specific construction, they still follow past construction experience, resulting in the lack of guarantee for the quality of steel structure construction. In the construction of steel structures, there is a great correlation between various sub items, processes, and before processes. In addition, there is a close relationship between the progress, quality, cost and safety of the project. If there is a problem in any node or link, it will have a chain reaction, affect the realization of other goals and expand losses. This paper first expounds the characteristics of building steel structure, then analyzes the safety risks of high-rise steel structure construction, and finally puts forward the safety management strategies of high-rise steel structure construction, including innovating steel bar welding technology, risk control of environmental factors, strengthening on-site supervision of construction projects and increasing the application of BIM technology.

Key Technology of TBM Excavation in Soft and Broken Surrounding Rock

Tunnel Boring Machine (TBM), as the most advanced construction equipment for rock tunnels, has been widely used in railway tunnel engineering, water conservancy tunnel engineering, urban rail engineering, coal mine roadway engineering, and other fields. However, the disadvantage of TBM lies in its poor adaptability to complex geological conditions, resulting in a significant reduction in tunneling efficiency and even major accidents due to improper TBM construction measures, especially in weak and fractured strata, which pose a great challenge to TBM construction. Therefore, it is necessary to study the key technologies of TBM construction in weak and fractured strata in order to improve the efficiency of TBM construction. Based on the background of the TBM construction of the Gaoligongshan Tunnel on the Southwest Darui Railway, this paper provides a reference for safe and efficient TBM excavation in weak and fractured areas through research on equipment, excavation parameter control, and construction measures.

Evaluation on key technologies for the construction of low-carbon index of electric power based on “double carbon”

Abstract At a time when global climate change poses a major challenge to human survival and development, all countries believe that people must actively deal with green and low-carbon (LC) development. As one of the hot topics in recent years, the concepts of “carbon neutral” and “carbon peak” have a significant impact on the construction of New Energy (NE) systems. The construction of NE systems with NE as the main component is an important way to achieve the “double carbon” goal. Affected by the “double carbon” goal, the energy system has shifted to a low carbon and high intensity system, reducing the dependence on fossil fuel power generation, accelerating the use of clean energy, and promoting the supply system of low carbon and clean energy. In order to improve the LC construction of electric power, this article studied the key technologies of LC index construction of electric power under the background of “double carbon”. This article first introduced the LC construction of urban electric power, including the connotation of LC electric power, the current situation of NE development and the difficulties of LC construction of electric power in the context of “double carbon”. Then this article constructed a new type of LC Power System (PS) on the basis of double carbon, and introduced the framework of the system and the key technologies included in the system. Finally, this article verified the effectiveness of the new LC PS in LC construction through experiments, and put forward suggestions for the realization of LC power construction. The experiment showed that the new LC PS can greatly promote the construction of the LC index of power, and is conducive to the development of urban power. The proportion of urban non-fossil energy and the new installed capacity of non-fossil energy power generation have been significantly increased. Among the four cities studied in this article, the proportion of non-fossil energy in two cities has increased from less than 50 % to more than 50 %, which has greatly promoted the construction of LC index of electricity.

Research on key technologies for intelligent and fine-grained construction of earth–rock dams based on artificial intelligence

Abstract High dam construction is continuing to develop with new requirements for intelligent dam construction. New information technology capabilities are providing paths for improved intelligent dam construction. This paper provides a comprehensive overview of the key technologies employed in the intelligent construction process of earth–rock dams. Starting with the multidimensional perception technologies and equipment utilized in earth–rock dam filling construction, it covers various aspects, such as the fine-grained management of unit construction based on building information modeling, rapid detection and qualification testing of dam materials’ physical characteristics, fast perception technology for material compaction, and unmanned driving technology for dam compaction equipment. Additionally, this paper highlights an overview of the existing technical challenges and future prospects in intelligent construction for earth–rock dams. These research results provide important references and lessons for the construction and development of high earth–rock dam engineering.

CASE STUDY ON THE LARGE DIAMETER PIPE JACKING FOR UTILITY TUNNEL

Pipe jacking have been widely used in utility tunnel constructions as an environment-friendly method in China. This study is focus on the critical technologies used in the pipe jacking for the utility tunnel in Huanggang Mingzhu road. The inner and outer diameter of this utility tunnel are 4m and 4.8m respectively, which is the largest circular pipe jacking project in China at present. This utility tunnel is designed under the urban main road with a heavy traffic, so the control accuracy of pipe jacking construction is required to be high. According to the characteristics of the project and actual construction technical measures, the key construction technologies including pipe jacking equipment, launching of small spacing, slurry circulating, the drag reduction technology, and the control of surface settlement are discussed in this paper. Meanwhile, the jacking force and ground settlement during pipe jacking construction are monitored. The results show that the selected pipe jacking machine has good adaptability to the geological conditions of the project. The actual jacking force is much smaller than the theoretical value, and the two intermediate jacking stations are not activated. In addition, the road surface deformation is -8–5mm during the whole process of pipe jacking construction, which has no impact on surface traffic.

Design and key construction technology of steel-concrete-steel sandwich composite pylon for a large span cable-stayed bridge

This paper introduces a new type of steel-concrete composite pylon that has been applied to Nanjing Fifth Yangtze River Bridge (a three-pylon cable-stayed bridge with a main span of 600 m). For this new type of pylon, the steel shells are connected with concrete through PBL shear connectors and studs, and the inner steel shells are connected with the outer steel shells by angle steels. Numerical analysis and full-scale model tests show that the pylon structure exhibits excellent mechanical properties and construction performance. The application of BIM technology, the research and development of special spreaders and construction platforms ensure the precise installation of structures. Highly factory-manufactured modular assembly of the reinforced steel shell structure can effectively reduce the intensity and difficulty of on-site operations, and improve the quality of the project, with low construction risks. Whereas, the successful application of this steel-concrete-steel sandwich composite pylon marks the formation of a complete set of construction technology of steel-concrete-steel sandwich composite pylon, which can be widely used in similar bridges.

Intelligent renovation of existing Olympic venues: digital design and construction strategy of a DfD-based prefabricated structure system

This article introduces introduces a new prefabricated and assembled steel structure system and its key construction technologies for repeated switching scenes in existing stadiums. This steel structure system follows the DfD design method, minimizing the volume of each group of structural member units and separating the connection interfaces between members. In order to improve the construction and assembly efficiency of all the structural components, this study establishes an assembly-oriented BIM model data system by adding customized attributes in the family library in Autodesk REVIT. By associating model attributes with on-site monitoring data of the construction process, this research realizes real-time acquisition and display of construction data of all components during the whole life cycle. At the same time, aiming at the requirements of high-precision positioning and digital dynamic monitoring in future on-site construction, this research proposes an innovative construction positioning monitoring method which combines motion capture system with traditional construction monitoring technology. By correcting the positioning data of motion capture system with traditional construction monitoring data, real-time dynamic monitoring of several monitoring points in a 12*15 m large site is realized and the measurement error is controlled within ±1 mm. This study takes the construction project of “ice-water conversion” from the main swimming pool of the National Swimming Center in the Summer Olympic Games to the curling venue of the Winter Olympic Games as an example to show the important role of relevant technology to improve the construction efficiency in the construction application for the renovation of existing Olympic venues.

Replacing construction technology of corroded ground wire of 500KV line across three 220KV transmission lines in the same gear

With the increase of the operating time of overhead transmission lines and the intensification of equipment aging and corrosion, the replacement of rusted ground wires has increased significantly. Due to the fact that there are many crossovers of overhead transmission lines and the mechanical properties of corroded ground wires are degraded, there is a high risk in replacement construction, especially when multiple high-voltage power lines are crossed in the same gear. Taking the replacement construction of corroded ground wire of a 500 kV transmission line spanning three 220 kV power lines in the same span from Pingguo to Laibin as an example, the methods, steps and safety precautions used in the replacement construction are introduced. In order to reduce the risk in the replacement process, measures were taken to seal the wire mesh, install wire ropes on the ground wire bracket for secondary protection, reasonably set up the stretch field, reduce the ground wire traction speed, and cast and withdraw the reclosing of the crossed lines one by one. These measures have been proven safe and effective on site, and can well protect the safety of the power lines being crossed and reduce the risk of construction operations. These key technologies in construction have important reference significance for carrying out similar operations in the future.

Study on the Application of Non-Plastering Technology of BM Lightweight Aggregate Interlocking Block

Benchmark (BM) lightweight aggregate interlocking block has the characteristics of energy saving, no plastering, convenient construction, etc., which can be used for internal infilled walls at all parts (240 mm thick block can also be used for external infilled walls). The U-shaped bricks are used in building ring beams, structural columns and lintel formwork. It eases the formwork construction process, saves energy consumption, shortens the construction period, and reduces the materials used, achieving the purpose of ensuring a high-quality building at minimum construction cost. Taking the practical project as an example, this paper studies the performance and characteristics of BM light aggregate interlocking block, and introduces the key construction technologies, aiming to provide relevant reference for the application of BM light aggregate interlocking block in practical projects.

Key Construction Technology and Monitoring of Long-Span Steel Box Tied Arch Bridge

Key Construction Technology and Monitoring of Long-Span Steel Box Tied Arch Bridge