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30 June 2022, Volume 32 Issue 2 Previous Issue    Next Issue
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China Grand Canal Research Column
Electrical Engineering Column
Project Management Column
Column on Water Conservancy Engineering and Water Conservancy Informatization
Road and Bridge Engineering Column


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China Grand Canal Research Column

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Basic Context and Historical Role of Channel Change of China's Grand Canal LV Juan 2022, 32(2): 1-7.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.001 Abstract ( )   PDF (1032KB) ( )   From the spring and Autumn period to the contemporary era, the canal channel has been changing for more than 2500 years, which has roughly experienced several stages. In the pre-Qin period the canal between the middle and lower reaches of the Yangtze River and the canal connecting the Yangtze River and Huaihe River system were dug for the needs of war. From the Qin and Han Dynasties to the northern and Southern Dynasties, the canals connecting the Yangtze River and pearl river systems, the Yellow River and Haihe river systems were dug and the previous canals were dredged to maintain the operation of the ruling class’s political power.During the Sui, Tang and Song Dynasties, the national east-west Grand Canal system was formed and during the Yuan, Ming and Qing Dynasties, the national north-south Grand Canal system was formed. Then the Grand Canal has experienced the decline of the Republic of China and the revival since the founding of new China. The Grand Canal channel is already a cultural heritage and a witness of China's historical development. Therefore, in the process of protection, inheritance and utilization, the Grand Canal channel should be protected in the first place. References | Related Articles | Metrics

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Analysis and Research on Water Environment Quality of Cangzhou Section of South Canal CHENG Lin 2022, 32(2): 8-12.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.002 Abstract ( )   PDF (1042KB) ( )   In recent years, affected by the water diversion project and the construction of the Grand Canal landscape belt, the ecological environment on both sides of the South Canal has been significantly improved, and the quality of the water environment has gradually changed. Using the water environment quality index evaluation method, through the systematic analysis of the water environment quality of the Cangzhou section of the South Canal in recent years, the change law of the water environment quality is found, the influencing factors are determined, and effective measures and suggestions are put forward. The purpose is to provide a powerful reference for further promoting the prevention and control of water environment pollution, improve the quality of the water environment, and restore the ecological function of the water, so as to truly realize the ecological beauty of the Grand Canal, which is livable and suitable for swimming. References | Related Articles | Metrics

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Coupling and Coordination Analysis of Land Use and Ecological Environment along 4km of Cangzhou Section of the Grand Canal from 2014 to 2020 HUO Fei, WAN Hong-lin, ZHANG Tian-xing, ZHANG Wei, ZHANG Li-jun 2022, 32(2): 13-19.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.003 Abstract ( )   PDF (1308KB) ( )   In view of the unclear interactive coupling relationship between land use and ecological environment along the Grand Canal, taking 4km along the Cangzhou section of the Grand Canal as the study area, a coupling coordination model is established to evaluate the relationship between land use and ecological environment in the study area by using the land use data of 2014, 2018 and 2020 and the ecological environment data evaluated by RSEI model. The results show that from 2014 to 2020, within 4km along the Cangzhou section of the Grand Canal, the main land use types are cultivated land and construction land, accounting for more than 95%, and the ecological space along the Grand Canal is seriously occupied. The overall ecological environment quality index RSEI shows a downward trend, with a decrease of 9.5%. Forest land and grassland make positive contributions to the ecological environment, and construction land makes negative contributions to the ecological environment. By 2020, the coupling relationship between land use and ecological environment is extremely uncoupled, and the development of land use lags behind, indicating that the contradiction between land development and utilization and ecological environment is further intensified, and the unreasonable use of land has a negative impact on the ecological environment. References | Related Articles | Metrics

Electrical Engineering Column

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Research on Isolated Three-phase Bridgeless Sepic PFC Converter Based on One-cycle Control ZHANG Chun-jiang, TANG Jia-lin, XU De-xun, GAO Jia-ning, SHI Bing-qian 2022, 32(2): 20-28.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.004 Abstract ( )   PDF (2020KB) ( )   Power factor correction technology is widely used in rectifier circuits to reduce harmonic pollution. Firstly, this paper studies a new type of isolated three-phase bridgeless Sepic PFC converter, which can realize power factor correction and isolated DC/DC conversion through one-stage conversion. In this paper, each working mode of the three-phase bridgeless Sepic PFC converter is analyzed in detail, and the continuous working conditions of the circuit are analyzed. Secondly, the one-cycle control technology is used to realize the closed-loop control, the core control equation of the one-cycle control is established, the small signal modeling is carried out, and the voltage loop controller is designed to stabilize the system under different parameters in the frequency domain and time domain respectively. The simulation analysis is carried out, and the realization method of digital one-cycle control based on DSP is designed. Simulation and experimental results show that the one-cycle control three-phase bridgeless Sepic PFC converter can achieve unity power factor and small current distortion rate. References | Related Articles | Metrics

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Study on Human Motion Recognition Based on Random Forest Algorithm and Multifunctional Triboelectric Sensor LENG Han-song, ZHANG Feng-duo, REN Li-jie, YANG Da-wei, WANG Zhi-hua 2022, 32(2): 29-34.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.005 Abstract ( )   PDF (1514KB) ( )   Human motion sensors are key sensors in wearable devices, Internet of Things and other fields. Low-cost polymer multifunctional motion sensors have broad application prospects.Based on the principle of triboelectricity, polymer sensors can realize a variety of motion sensing. The analysis of the sensor structure and charge transfer law shows that it can effectively sense three-dimensional linear motion. The output voltage under different motion states such as running and walking is measured by fixing the sensor at the ankle of the testers. The range and standard deviation of the output voltage of some electrodes are selected as the characteristic quantities, and the random forest algorithm is used to analyze the characteristic quantities. The research results show that the accuracy of this method for walking and running recognition can reaches 98.3%, laying the foundation for the application of this type of sensor on wearable devices. References | Related Articles | Metrics

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Analysis and Parameter Prediction of Electromechanical Force of Permanent Magnet Direct Current ZHANG Jun, ZHAO Lin-yu, LI Jian-sheng 2022, 32(2): 35-45.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.006 Abstract ( )   PDF (2175KB) ( )   Through variable analysis of the electromagentic force in the motor airgap, the influencing factors of electromagnetic noise are obtained. The modal frequency of the motor was first obtained by modal analysis. Then, the static magnetic field was analyzed under the condition of motor rotor eccentricity and different thickness of permanent magnet by MAWELL2D, and the influence of the two on the electromagnetic force in the air gap of the motor was obtained. Piezoelectric impedance experiment was used to obtain the modal frequency of the motor to verify the results of modal simulation. Finally, BP neural network was used to predict the thickness of the permanent magnet of the motor through the air gap electromagnetic force. The results show that radial electromagnetic force can be effectively reduced by avoiding rotor eccentricity and adjusting the thickness of permanent magnet appropriately. The BP neural network can recognize the thickness of permanent magnet through the air gap electromagnetic force. References | Related Articles | Metrics

Project Management Column

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Analysis on EPC Project General Contracting Management of Office Building Decoration and Renovation Project ZHANG Jin-tao, QIAN Yao, LI Zi-lin, WANG Xiu-ce, GUO Xiao-yu 2022, 32(2): 46-51.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.007 Abstract ( )   PDF (1499KB) ( )   Based on the management experience of decoration and renovation project, this paper analyzes the cost control management, schedule management and quality management of design work, supplier management and schedule management of procurement work in the EPC project general contracting management of decoration and renovation project, and summarizes the EPC contracting management of decoration and renovation project in combination with LSCS construction management system. References | Related Articles | Metrics

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Analysis of Technical Key Points of Water Resources Argument in Piedmont Area ——a case study of Henan Han-rong Drinks Company project GAO Liang, FENG Lin-wei 2022, 32(2): 52-56.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.008 Abstract ( )   PDF (1573KB) ( )   In order to ensure the water demand of the project, combined with the project scale and the type of water intake source, through the field work such as hydrogeological survey, geophysical exploration, pumping test and groundwater level survey, the hydrogeological survey data, pumping test results, the current situation and development and utilization of regional water resources in the study area are analyzed, the exploitable resources of groundwater in the study area are evaluated, and the drawdown of groundwater level after mining is predicted by analytical method. The results show that the water intake of the project is reasonable and reliable. The paper explores and practices the demonstration content and working method of taking groundwater as the water source, which provides a reference for the demonstration of water resources of construction projects in the piedmont area. References | Related Articles | Metrics

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Application of Combination Weighting Method in Risk Assessment of Offshore Wind Power Project YANG Huan, MA Zhao-yang 2022, 32(2): 57-62.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.009 Abstract ( )   PDF (1509KB) ( )   During the 14th Five-Year Plan period, China's offshore wind power projects will continue to develop rapidly. At the same time, the development of offshore wind power projects also faces many risks and problems. This article selects some offshore wind project in Rudong, Jiangsu province as the research object. By establishing a risk evaluation index system, the importance of each index is calculated by combining subjective weighting method (AHP) and objective weighting method (the entropy method), which avoids the subjectivity of subjective weighting method as well as the objectively absolute objectivity. The results show that the combination weighting method is more in line with the actual situation, which overcomes the one-sidedness of single weight, and makes the evaluation result more reasonable and reliable. References | Related Articles | Metrics

Column on Water Conservancy Engineering and Water Conservancy Informatization

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Analysis on Temperature Control of Concrete Engineering of Sluice Gate of Nianpanshan Water Conservancy Project LI Xin-yuan 2022, 32(2): 63-67.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.010 Abstract ( )   PDF (1553KB) ( )   In order to control the concrete pouring temperature of the sluice gate of the Nianpanshan Water Conservancy Project, and meet the requirements of the sluice gate's mass concrete entering temperature. Before the construction of the sluice sluice project, the concrete temperature control plan and design and calculation are carried out. During the construction period, the method of dynamic concrete temperature monitoring and real-time control is adopted according to the pouring schedule. Through calculation, the calculation results such as the maximum adiabatic temperature rise value of the sluice sluice concrete, the sluice sluice concrete center temperature value, the sluice sluice concrete surface temperature value, the sluice sluice concrete surface insulation material thickness value and other calculation results are obtained, which are analyzed and compared with the monitored raw material temperature monitoring value, the temperature monitoring value, the water cooling monitoring value of concrete in warehouse, the pouring silo temperature value, and the insulation temperature monitoring value. The resalts show the extreme maximum temperature in July, the large water height difference during the same period, and big difficuty in concrete temperature control due to frequent temperature drops. Based on the actual situation, the project adopts technical measures such as avoiding the parts with strict requirements for temperature control during the high temperature period, configuring sufficient refrigeration capacity of the cold water station, and timely covering the water surface after closing the warehouse to control the difficulty of concrete temperature control, which provides a certain theoretical and practical basis for temperature control in other mess concrete projects . References | Related Articles | Metrics

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Development and Application of Operation Management System for Farmland and Water Conservancy Projects in Hebei Province JIN Jiang-bo, LANG Zi-xue, JIN Zi-hang, LI Chao-yang 2022, 32(2): 68-71.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.011 Abstract ( )   PDF (1523KB) ( )   Through “Great Wisdom Propelling Clouds”,modern communication technology, Internet technology and information management technology, the operation management information system of farmland water conservancy projects covering the whole province of Hebei Province is developed, which can effectively realize the statistical analysis of agricultural irrigation water consumption and the calculation of effective utilization coefficient of agricultural irrigation water in the whole province, improve the management level of farmland water conservancy projects, and give play to the guiding role of irrigation prediction results in rational irrigation, and promote the efficient implementation of the comprehensive reform of agricultural water price, which provides technical support and means for the information management of farmland and water conservancy in Hebei Province. References | Related Articles | Metrics

Road and Bridge Engineering Column

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Construction Technology of Steel Box Girder Arch-on-support Method for the Fourth-line Bridge ZHANG Zhe 2022, 32(2): 72-76.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.012 Abstract ( )   PDF (1766KB) ( )   The steel box girder on the arch of Nujiang Fourth-line Super-large Bridge is constructed by the support method after scheme comparison. This paper carries out the design and working condition analysis of the support on the arch, and studies the key points and key technical measures of the hoisting construction of the steel box girder on the arch. The synchronous construction of steel box girder and steel-concrete composite beam is realized. The structure is stable and the linear control precision is high in the construction process. The smooth closure of steel box girder and steel-concrete composite beam is completed, which provides a reliable basis for the construction of steel box girder and steel-concrete composite beam of deck arch bridge. References | Related Articles | Metrics

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Exploration and Practice of BIM Technical Archives Storage in Highway Engineering ZHAO Hui-qin 2022, 32(2): 77-80.  DOI: 10.16046/j.cnki.issn2096-5680.2022.02.013 Abstract ( )   PDF (1532KB) ( )   In order to solve the problem of BIM technical archives storage of highway engineering, based on the accurate evaluation of the development status of BIM technical highway industry, the special research on the problems such as unclear basis of BIM technical archives archiving, failures in store and transmit correctly, and the short board of archives management personnel is carried out. In this paper, according to the above problems, the solutions of clarifying the basis of BIM technical archives archiving, constructing BIM technical archives storage and data transmission standards, standardize archives storage from multiple angles, and improving the professional quality of archives management personnel are proposed and the assumptions of BIM technical archives management in highway engineering construction and the prospect of further promotion of the development of BIM Technology by improving the informatization of highway engineering archives are put forward. References | Related Articles | Metrics