Home Table of Contents

01 October 2019, Volume 36 Issue 10
    

  • Select all
    |
    CONTRIBUTION OF INVITED EXPERTS
  • ZHANG Jia-fa, DING Jin-hua, ZHANG Wei, WU Qing-hua, WANG Jin-long
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 1-10. https://doi.org/10.11988/ckyyb.20191106
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The concepts of piping’s criticality and piping tending to breach dyke were presented in the light of some cases of piping happened in the Jingjiang stretch of Yangtze River dyke and the studies of piping modelling. The concept of piping’s criticality is conducive for the quantitative research on factors affecting piping’s evolution. Special influence factors on criticality of piping include: flood process, water level in the protected area, piping’s location, structure and soil properties near the piping and along its evolution path, as well as seepage control measures. Classifying piping according to criticality lays an important foundation for the separate treatment of different piping types,and is also a vital approach to improving the pertinence and scientific decision of piping treatment. Generally, piping in the embankment, and those extending fast to the embankment, should be recognized as piping tending to breach dyke, which should be followed with treatment measures to hinder the evolution, or emergency plans implemented immediately.
  • WU Ai-qing, ZHOU Hua-min, WU Qing-hua
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 11-18. https://doi.org/10.11988/ckyyb.20191016
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    China is one of the countries with the most severe flood disasters in the world. As an important measure to resist flood disaster, levee project is of strategic significance to the harmonious development of human and nature. In this paper we introduced systematically the basic situations of levee projects in China, Europe and the United States, and emphasized on the characteristics of flood risk and flood protection value, the safety standards and levee project construction, the legislation and management of levee, the daily maintenance and emergency rescue, and other engineering and non-engineering measures. Levee and flood defence in Europe and US are characterized by high safety standards, perfect legal management system and diversified flood risk transfer measures. Research on levee safety standard, risk evolvement mechanism, legislation,levee management , early warning and emergency rescue technology should be deepened in future to enhance the comprehensive strength of flood control and disaster reduction in China.
  • INFORMATION MANAGEMENT OF DYKE ENGINEERING
  • XU Zhi-min, ZHANG Li, MA Rui, FAN Qing-song, SHAO Wei-xuan
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 19-22. https://doi.org/10.11988/ckyyb.20190862
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Three-dimensional visualization of water surface is an important technical means to achieve realistic display of digital watershed. The existing three-dimensional visualization technology of water surface generally does not consider the characteristics of water surface ratio of natural river course, and it is difficult to apply to three-dimensional visualization of water surface at large scale and basin level. A three-dimensional visualization method of river surface water surface considering water surface ratio is proposed. Firstly, boundary point densification and polygon triangulation were performed on the river surface boundary polygon, and then the elevation of the polygon boundary point was interpolated and adjusted based on the river water level process data. The adjusted triangle mesh was used for water surface drawing. Based on the water level process data of the Three Gorges reservoir area, the three-dimensional visualization of the river surface was carried out. The results show that the method can effectively express the water level grading process of natural rivers.
  • ZHANG Jian, PAN Bin, CHEN Wen-long, ZHANG Yu, LUO Tian-wen
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 23-27. https://doi.org/10.11988/ckyyb.20190871
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this research we collected 32 radar satellite images from 2018 to 2019, and monitored the settlement of Jingjiang segment of Yangtze River dyke segment from Shishou to Jianli using PS-InSAR technology. We obtained the deformation trend and its physical mechanism by analyzing the average settlement rate from April 2018 to April 2019. Results unveiled uneven settlement in this segment of dike; but the deformation trend changes with time in a year. Radar satellite time series analysis technology could highly-effectively monitor the settlement of Jingjiang River dyke in a large range, which suggest that radar satellite time series analysis has great application potential in the deformation monitoring of the Yangtze River embankment.
  • CAO Bo, CHEN Wen-long, WEI Si-qi
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 28-33. https://doi.org/10.11988/ckyyb.20190873
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The establishment of the stereoscopic monitoring and management information system for riverbank dynamic changes is based on China’s relevant regulations in line with the actual situation of riverbank management. The system is composed of three parts: the riverbank remote sensing image management and dynamic monitoring system based on C/S frame (space-based monitoring), the integrated riverbank supervision management system based on C/S frame (network management), and the mobile survey system based on mobile terminal (ground survey). The system adopts advanced remote sensing monitoring technology acquiring multiphase images by satellite and UAV, and perceives the abnormal changes via overlay analysis, such as land use change, embankment damage, invading and occupying riverbank territory and water conservancy facilities, and so on. It can assist relevant authorities in the dynamic monitoring and management of riverbank by professional data.
  • LUO Deng-chang, HAN Xu, YU Qi-chao, MA Dan-xuan
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 34-38. https://doi.org/10.11988/ckyyb.20190877
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The standards of dyke engineering data should be determined and the standardization schemes of different types of data should be defined in an aim to enhance effective data collection, orderly storage, and rapid and accurate analysis and utilization. In this paper, the status quo of data standardization research in China and abroad are investigated in eight aspects, namely, engineering data, hydrometeorological data, humanistic and economic data, geographic data, geological data, geophysical data, danger data, and monitoring data involved in dyke engineering. The standardization of dyke engineering data should include three contents: structured data, unstructured data, data warehousing and cleaning. Structured data can be standardized through data classification, data coding, and table design; unstructured data can be standardized via describing key information of documents by Java Script Object Notation(JSON) storing the documents together with JSON in the database; the efficiency of data standardization can be improved by uniform data warehousing and dynamic cleaning.
  • EVOLVEMENT MECHANISM OF DYKE RISKS
  • WU Qing-hua, ZHANG Wei, WU Ai-qing, ZHOU Hua-ming, CUI Hao-dong
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 39-44. https://doi.org/10.11988/ckyyb.20191007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    At present, research of piping hazard mainly focuses on evolution mechanism, physical model test and numerical simulation method, as well as emergency rescue technology in flood season and non-flood season. Piping hazard is controlled by factors such as critical hydraulic conditions and formation lithology structure; however, river dynamics and continuous-discontinuous piping expansion process has not been systematically considered, and the scale effect of physical model exists. In flood season, conventional manual power is the dominant emergency treatment, which is obviously inefficient; in non-flood season, relief wells and cutoff wall are major countermeasures. Removable relief well has successfully solved the silting problem of traditional relief wells and significantly improved operation efficiency; vertical impermeable wall has remarkable seepage control effect, but its operation effect is difficult to command due to high engineering cost and lack of monitoring and evaluation of the whole life cycle. The effect of soil-water coupling, portable-equipped emergency materials and equipment are urgent problems and research directions of dyke piping.
  • NING Dan-mai, LUO Yu-long, ZHAN Mei-li, SHENG Jin-chang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 45-48. https://doi.org/10.11988/ckyyb.20190870
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this paper a generalized double-layer foundation levee model is built to conduct sensitivity analysis on four major assessment indicators. These indicators include the water head difference between both sides of levee, the duration of warning water level, the thickness of less permeable layer, and the ratio of permeability of strongly permeable layer to that of less permeable layer. The objective weights of these four indicators influencing backward erosion piping are determined. Results indicate that the water head difference and the thickness of less permeable layer (less than 2 m) are two important indicators with relatively large weights. Meanwhile, the objective weights of three indicators, namely, the duration of warning water level, the thickness of less permeable layer, and the ratio of permeability coefficient, vary in different ranges.
  • LI Shao-long, CUI Hao-dong
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 49-52. https://doi.org/10.11988/ckyyb.20190769
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The significant spatial variability of soil property is a difficult problem for risk management of levee. On the basis of analyzing the spatial variability of soil permeability, the statistical characteristic of seepage field and seepage stability of levee foundation is studied by stochastic numerical method. Random field model is adopted for soil permeability, and the turning bands method is employed to simulate the permeability random field. The distribution of seepage field and probability of seepage failure are evaluated by Monte-Carlo method. The presented approach is applied to a case study. Results imply that the spatial variability of soil permeability has great impact on seepage field; with the increase of variation of permeability and critical gradient, local seepage is highly concentrated, and seepage failure probability of levee foundation also increases.
  • SAFE OPERATION ,MONITORING AND EARLY WARNING OF DYKE ENGINEERING
  • LIU Gao-feng, GONG Yan-bing, WANG Hui-min, LAI Xiao-ying
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 53-58. https://doi.org/10.11988/ckyyb.20190997
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Levee is an important part of flood-control engineering system in China, and is the barrier to protect people’s life and property from flood disasters, playing a significant role in flood control practices. The current situations of levee’s risk management in various countries including the Netherlands, UK, France, Belgium, USA, Japan and China are introduced. Comparative study shows that risk management mode abroad is co-governance by government and stakeholders, and generally a special water management department is set up to take charge of all water affairs, attaching importance to daily management and maintenance, conducting in-depth investigations regularly, and emphasizing the information construction of levee databases and networks. The risk management of levees abroad tends to be socialized in disaster prevention. In reference to experiences abroad, the risk management of levees in China should be strengthened from improving safety standard, changing flood control concept, enhancing legislation, and risk management socialization and intelligence, to promote flood control capacity.
  • YANG Duan-yang, WANG Chao-jie, GUO Cheng-chao, HAO Yan-jie, LIU Qi
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 59-65. https://doi.org/10.11988/ckyyb.20190881
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The safety assessment for levee, an essential part in flood control system, is of vital importance. In this paper, the research status of levee’s failure mode, risk analysis method and uncertainty in flood risk model is discussed. Meanwhile, the application status in China and abroad, advantages and disadvantages, as well as applicability of the uncertainty analysis methods, such as reliability analysis, fuzzy comprehensive evaluation, grey system evaluation and artificial neural network, are expounded. However, due to the complexity of the levee system and the uncertainties of the risk model, the risk analysis method based on artificial intelligence has better application prospect in the levee system than other methods. Finally, problems to be solved in risk analysis of dike engineering are also pointed out.
  • DING Jia-yi, CAI Wei, ZHOU Jian-fang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 66-72. https://doi.org/10.11988/ckyyb.20190883
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Despite deep research and broad application of safety analysis methods for levees based on stochastic mechanics in recent decades, systematic summary is still in lack. This paper aims to make a review on the main contents and engineering applications of safety analysis methods for levee based on stochastic mechanics. In the light of three typical failure modes of levees, the risk factors that should be considered in safety analysis are analyzed, and the uncertainty and correlation of risk factors are systematically sorted out. Commonly adopted safety analysis methods based on stochastic mechanics are also summarized with their applications in the aforementioned typical failure modes; the safety analysis methods based on random field theory and intercorrelation of risk factors are expounded with emphasis. It is concluded that the key problems for the development of levee safety analysis method based on stochastic mechanics is the research of finite element method for random field and the intercorrelation among risk factors.
  • HAO Yan-jie, ZHANG Jian-qiang, GUO Cheng-chao
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 73-78. https://doi.org/10.11988/ckyyb.20190874
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The research status of detection and identification technologies for hidden dangers or disasters of dike project, including piping and dam break, are summarized. The characteristics, applicability, and engineering application of common methods in detecting hidden dangers of dike, namely, high-density resistivity method, ground penetration radar imaging, magnetoelectric method, transient electromagnetic method, and flow field method, are analyzed. Moreover, the theories and engineering practices of hidden danger identification technologies based on experts’ experiences, event tree analysis, sensitivity analysis, neural network, grey theory and artificial intelligence are expounded. The related theories provide necessary theoretical foundations for some existing problems and engineering applications that will be carried out in the future.
  • ZHAO Xin, MA Gui-sheng, WAN Yong-liang, WAN Zhi-jie
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 79-84. https://doi.org/10.11988/ckyyb.20190880
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    At present, the safety assessment method of dyke engineering is qualitative, and there are many factors, both quantitative and non-quantitative, that affect the safety of dykes. Because of the uncertainty and fuzziness of the indicators, the final result of the safety assessment of dyke is uncertain and random. In order to establish a quantitative safety assessment system for dyke, we build a safety assessment model for seepage flow in dyke foundation using analytical hierarchy process (AHP) in which the main controlling indicators are given weight by subjective experiences of experts. The model is validated by using specific engineering examples. Consistency between calculation result and engineering practice demonstrates that the presented quantitative safety assessment model based on AHP is accurate and operable. It proves that the safety evaluation system of dyke engineering established by AHP is accurate and operable.
  • LIU Shi-zhen, FAN Xiao-tao, FENG Guo-zheng, REN Yong
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 85-88. https://doi.org/10.11988/ckyyb.20190886
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Bank collapse monitoring is of vital significance as bank collapse is highly concealing and happens in a sudden with great harm. With the development of Unmanned Aerial Vehicle (UAV), multi-beam, three-dimensional laser scanning, aperture radar and other technologies, a modern emergency monitoring system with high spatial-temporal resolution for bank collapse has developed. The system composes amphibious ship-borne high-resolution terrain acquisition, UAV wide-area coastline inspection and danger monitoring, real-aperture radar monitoring and early warning of bank collapse. In this paper, the structures, characteristics, applications, and prospects of each monitoring approach in the system are expounded. Such emergency monitoring technology system makes it possible to quickly and accurately monitor and perceive the development and evolution of dangers, thus offering reliable technical support for the early warning and treatment of bank collapse and subsequent river regulation.
  • WANG Xiao-bing, XIA Xiao-zhou, ZHANG Qing
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 89-93. https://doi.org/10.11988/ckyyb.20190868
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    It is not convenient to calculate failure probability using traditional reliability theory for complex structures such as levee slope whose performance function cannot be explicitly expressed. In this paper, neural network model is used to replace the performance function of slope and the Monte-Carlo method is used to calculate the failure probability. The samples for training network are generated through orthogonal trial, and the safety factors of the samples are calculated by the strength reduction method of finite element method (FEM). The failure probability is calculated by constructing performance function by using the strong non-linear fitting ability of neural network. Through an example calculation, the failure probability of levee slope is studied with internal friction angle, cohesion force and elastic modulus as random variables. This method is proved to be simple and reasonable.
  • FENG Guo-zheng, LIU Shi-zhen, LI Yan, PENG Chang, YANG Xiu-chuan, CHEN Xi-run, LONG Hong
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 94-99. https://doi.org/10.11988/ckyyb.20190869
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to solve the technical problem of space-time registration of ship-borne multi-sensor land-water three-dimensional monitoring system and separate surveying and mapping of land-water topography in landslide monitoring, we propose to use the tight-coupled data post-processed by GNSS(Global Navigation Satellite System) and INS(Inertial Navigation System) integrated navigation system to match time and calculate space of land-water three-dimensional monitoring data in landslide monitoring. Accurate, efficient and safe acquisition of monitoring data of bank collapse is realized. Error analysis demonstrates that the positioning accuracy of GNSS and INS integrated navigation is better than 2 cm. Test data show that the median error of land survey points is better than 10 cm, and that of water survey points is better than 15 cm, which meets the requirement of bank collapse monitoring accuracy. The 3D integrative bank collapse monitoring system with tightly coupled GNSS and INS can be extensively applied to bank collapse monitoring in navigation segment and provides new technical programme as it can obtain precise, highly efficient, and safe monitoring data.
  • MA Yao-chang, LIU Shi-zhen, FAN Xiao-tao, ZHOU Wei
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 100-103. https://doi.org/10.11988/ckyyb.20190903
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The multi-beam technology is extensively applied in bathymetry, which in turn poses higher requirements for the observation accuracy of multi-beam technology. In this paper, the parameters of fine monitoring of bank collapse are designed and studied based on the resolution model of SONIC2024 multi-beam sounding system. The distribution rules of lateral and longitudinal resolutions are obtained respectively. The relations and recommended values of parameters inclusive of sampling rate, emission angle, maximum effective navigation speed, and sector’s opening angle are deduced. It is concluded that the vertical resolution of SONIC2024 sounding system is better than the lateral resolution. The conclusion can be used as the basis for the technical design of key parameters before multi-beam measurement. Finally, the process of designing the parameters is summarized, and some suggestions for setting these parameters in the fine monitoring of bank collapse are put forward.
  • RAO Xiao-kang, MA Rui, ZHANG Li, YI Chong-zheng
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 104-110. https://doi.org/10.11988/ckyyb.20190948
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A big data safety management platform for dyke engineering is presented in this paper. The internet of things (IoT) technology is adopted to build a cloud platform for the monitoring, collection, exchange, and sharing of massive data in the monitoring system. Meanwhile, big data and artificial intelligence technologies are employed for the fusion and sharing of massive, multi-source and heterogeneous data to identify and evaluate risks and construct early-warning model. Through the data acquisition and collection by the IoT monitoring platform, the model predicting the gradation after sandstone blasting is built to design the optimum blasting scheme and control the particle gradation of sandstone material. Engineering practice has demonstrated that the average relative error rate of controlling the gradation is within 21%, which meets the requirement and guarantees the dyke construction quality.
  • MA Rui, DONG Ling-yan, YI Chong-zheng
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 111-116. https://doi.org/10.11988/ckyyb.20190978
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The management information of dam safety is not comprehensive enough and the data is not fully visible. In view of this, we employed the Internet of Things technology to construct an information perception system covering the dam’s air, ground surface, interior and underwater spaces. Faced with the technical difficulties of massive terrain scheduling, dam and terrain inlay, and the expression of safety information in three-dimensional space, we designed a dam safety management platform integrating the Internet of Things technology and 3D visualization technology to display dam safety information in real geography. The rapid, efficient and intuitive display of space provides managers with a means to quickly obtain dam safety status, improve the dam safety management level, and overcome the shortcomings of intelligent dam safety management in the field of information technology.
  • LIU Cheng-kun, MA Rui, YI Chong-zheng
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 117-121. https://doi.org/10.11988/ckyyb.20190944
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The aim of this research is to enhance our cognition on the details of inundation area in the flood risk display by MIKE FLOOD model, and reflect dynamically the flood propagation process when danger such as a breach occurs. We summarized the existing expression methods of flood risk, examined the fusion and expression methods of flood process in 3DGIS scene, and built a program framework for 3D dynamic derivation of flood risk. With the South Juma River in Xiongan New Area as a case study, we calculated the flood process after the dam break based on the MIKE Flood models, constructed a 3DGIS environment using the Open Scene Graph technology, and analyzed the flood process in a real three-dimensional topography. Result demonstrates that the presented method is prior to conventional 2D method in terms of detail expression and dynamic simulation. It can also describe the inundation process in multiple scales, and reflects the dynamic flood process more intuitively and efficiently.
  • LU Yun-feng
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 122-126. https://doi.org/10.11988/ckyyb.20190864
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the scheduling of river-type reservoir, the impact of inflow flood, artificial regulation, and river basin topography on the flood routing process should be considered. By summarizing the research findings of flood wave features and dynamic reservoir capacity, we made it clear that the scheduling of river-type reservoir should be accomplished by coupling hydrologic and hydrodynamic models, and meanwhile that attention should be paid to the disturbance of artificial scheduling on the stage-discharge relation at dam site. We summarized that the effect of water flow structure on riverbed roughness should be taken into consideration in the calculation of reservoir flood routing. Furthermore, we reviewed the research achievements up to now of the flow characteristics near dam and pointed out that the three-dimensional flow characteristics near dam are remarkable. Taking the cross-section near dam as the boundary condition may cause systematic errors in calculation. In order to improve the accuracy of flood routing model, in future we should conduct in-depth research on the influence of manual regulation on the conveyance capacity of the cross-section near dam and roughness calibration.
  • DENG Cai-yun, LI Ling-yun, ZHU Yong-hui
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 127-130. https://doi.org/10.11988/ckyyb.20190781
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to numerous influencing factors and complexity of the interaction mechanism among these factors, current study on riverbank stability is still difficult to meet the demand of quantitative calculation. In this paper, a riverbank stability evaluation index system is constructed by combining qualitative analysis with quantitative calculation. In this process, the basic principle of selecting the evaluation indexes of riverbank stability is analyzed. The evaluation index system of river bank stability is divided into three layers: target layer, attribute layer and index layer. According to the current situation, influencing factors and change process of riverbank stability, the current situation of bank line, the geological condition of bank slope, the condition of bank protection completeness, the change of river regime, and the scour degree and slope of river bed near bank are analyzed. The reliability of evaluation results in the process of river bank stability assessment is also discussed.The discussion and analysis demonstrate: the riverbank stability evaluation index system is based on the quantitative attempt of multiple dynamic variable factors; the validity of the system depends on the reliability and representativeness of the monitoring data of the nearshore riverbed; further study can be performed in terms of quantitative or optimal calculation methods for specific river sections as well as the verification of the riverbank stability evaluation index system.
  • EXPLORATION OF NIDDEN TROUBLES IN DYKES
  • LI Wen-zhong, XIAO Guo-qiang, SUN Wei-min, HE Xiao-min, ZHOU Hua-min
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 131-134. https://doi.org/10.11988/ckyyb.20190928
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    This paper introduces in detail the test method of moisture content and compactness of silty loam sample collected from Honghu segment of Yangtze River Embankment, the design and calibration of resistivity sample box, the test principle of resistivity and the process and steps of resistivity measurement. On the basis of analyzing test results, the correlations between moisture content, compactness and resistivity of silty loam sample are summarized. Under given compactness, water content displays a progressively decreasing power function with resistivity; at given water content, compactness is in a negative relation with resistivity. The measured resistivity range indoor is overall consistent with on-site detection result. The findings of laboratory tests will be of great significance in improving the quality of inversion interpretation and judging the nature and physical status of hidden dangers.
  • ZHOU Hua-min, XIAO Guo-qiang, ZHOU Li-ming, ZHANG Min, FU Dai-guang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 135-140. https://doi.org/10.11988/ckyyb.20190882
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The detection of hidden dangers of embankment plays an important role in guaranteeing the safe operation of levee project. There are various geophysical detection methods for hidden dangers, each having their own advantages and applicability. It is difficult to solve all kinds of hidden danger detection problems by only one method. According to the geophysical parameters such as conductivity and dielectric property, the commonly used geophysical detection methods for hidden dangers of embankment are summarized. Moreover, through laboratory geotechnical tests, the correlation between resistivity, dielectric constant, moisture content and compactness of embankment soil is established, which provides an experimental and theoretical basis for improving the accuracy of geophysical interpretation. With the Yangtze River embankment project as a case study, the selection of geophysical detection methods, the arrangement of survey lines, the geological interpretation and detection effects are analyzed. It is verified that the comprehensive geophysical detection method can improve the detection precision of hidden dangers and achieve the purpose of accuracy, efficiency and economy.
  • YANG Jun-jie, XU Zhi-min, MA Rui, MA Sheng-min, ZHANG Li
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 141-145. https://doi.org/10.11988/ckyyb.20190878
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In detecting hidden dangers of dyke, the configuration of survey line is ineffective, and the interpretation result of 2D images could hardly describe hidden dangers or anomalies effectively. In view of this, the 3D model of dyke segment and the 3D terrain model around the dyke are established based on the 3D geographic information service platform. The geophysical prospecting database for hidden dangers of dyke is established, and a detection and analysis system is developed. Moreover, the data interface, database storage and 4D visualization expression of geophysical prospecting results are developed. In conclusion, the 4D visualization expression, dynamic analysis and management of time-lapse dyke detection results are realized.
  • ZHOU Li-ming, CHEN Zhi-xue, ZHOU Hua-min, FU Dai-guang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 146-150. https://doi.org/10.11988/ckyyb.20190885
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Transient electromagnetic method (TEM) has become an important geophysical survey method as it is capable of detecting in large depth with accurate positioning unaffected by topographic fluctuations. The three-dimensional forward method of transient electromagnetic method mainly includes finite element method, finite difference method, and integral equation method. In the present paper, finite element method is applied to the 3D forward modelling of transient electromagnetic for various hidden dangers of embankments. Comparison between the 3D forward computation results and the inversion results of field measured data demonstrated that the transient electromagnetic method is sensitive to low resistivity zone, thus having good detection effect for low resistivity anomalous zone of different shapes. Therefore, it is feasible to adopt transient electromagnetic method for the rapid survey of embankment’s hidden dangers. The research results in this paper can be used for reference in applying geophysical prospecting technology to the detection of hidden dangers in embankments.
  • ZHANG Yang, ZHOU Li-ming, XIAO Guo-qiang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 151-156. https://doi.org/10.11988/ckyyb.20190889
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In view of the electrical characteristics of the media of different potential geological defects in embankment, corresponding geophysical models are built using the finite difference time domain (FDTD) algorithm with the perfectly matched layer absorbing boundary conditions (PML). GprMax software together with MatLab self-programming is employed for the GPR forward simulation. Result reveals that the amplitude and form of GPR reflected wave of hidden defects vary with shape, location, and electrical parameters. Forward simulation result accurately reflects the depth and horizontal position of hidden defects. Two engineering examples demonstrate that the results of GPR forward simulation are basically consistent with engineering verification, which proves that GPR can effectively detect the hidden dangers of embankment. The GPR forward simulation method is feasible, and is helpful to guide the further interpretation work more precisely.
  • SUN Wei-min, SUN Da-li, LI Wen-zhong, QI Yan-fu, SUN Nai-quan
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 157-160. https://doi.org/10.11988/ckyyb.20190887
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The development of time-lapse prospecting technology is briefed through summarizing the methods of detecting hidden dangers of dykes. The working principle of time-lapse high-density resistivity method is expounded from aspects of observation mode, data acquisition and processing, inversion and image rendering, as well as anomaly judgment method. The effectiveness of time-lapse high-density resistivity method in detecting hidden dangers of dyke is examined by 3D forward simulation of two typical hidden dangers, namely, cave and leakage. Moreover, pilot demonstration of the techniques of time-lapse high-density resistivity method is presented based upon engineering practice. Furthermore, the possibility of time-lapse prospecting technology in dynamic detection of hidden dangers of dyke are evaluated in conditions of long distance of dyke and concealing, abrupt, lasting, and lowly detectable dangers.
  • LI Wen-zhong, SUN Wei-min
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 161-164. https://doi.org/10.11988/ckyyb.20190888
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The working principle, characteristics and application status of distributed high-density resistivity method are expounded from perspectives of electrode combination, data collection and inversion interpretation. The detection effects of wenner device (α), wenner-dipole device (β) and schlumberg (α2) in karst, soft interlayer, high-resistivity body, lithological interface division and structural detection were compared and studied with engineering examples. The advantages and disadvantages, accuracy and applicability of three common types of distributed high-density resistivity devices in stratum detection, detailed detection of low and high resistivity bodies are summarized and analyzed systematically. It is necessary to select more than two types of device according to the purpose and precision of the exploration in line with geological conditions.
  • FAN Bing-sen, GUO Cheng-chao
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 165-168. https://doi.org/10.11988/ckyyb.20190940
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The location and permeability of reservoir leakage, a common disease of reservoir, are difficult to be discovered accurately due to complex geological conditions. As a nondestructive detection method highly sensitive to low-resistance anomalies, high-density resistivity method is often used in geological prospecting at present. To investigate the effect of high-density resistivity method in detecting reservoir leakage, we adopted the dipole-dipole detection method for the nondestructive inspection of leakage of a reservoir as a case study. By analyzing the resistivity change together with on-site drilling results, we obtained the leakage position and analyzed the cause of reservoir leakage. The leakage position, cave location, and developed zones of corrosion fissures are highly consistent with inspection results by the high-density resistivity method, indicating that the method is efficient and feasible in reservoir leakage detection.
  • TREATMENT OF DYKE RISKS
  • XIONG Yong, CHENG Yong-hui, CHEN Hang
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 169-174. https://doi.org/10.11988/ckyyb.20190780
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The technology of blocking dyke burst has been developing gradually due to frequent dyke bursts in history. However, the blocking technology needs to develop towards modernization due to low efficiency, high dependency on manual power, and low degree of mechanization. In this paper, we made a review on the studies and practices of dyke burst and obtained some conclusions: the discharge and flow velocity at dyke breach can be deduced according to the shape and width of breach as well as the water depths on both sides of the dyke. The shape and width of the breach is determined by water head and affected by discharge of river channel and filling material of dyke. In spite of differences in emergency rescue technologies corresponding to different watersheds, the core principle is to dumping materials step by step and reduce flow velocity gradually. The key to successful blocking is to ensure the anti-scouring stability of dumping materials, which can be enhanced effectively by anti-scouring structure. In addition, light and convenient modern rescue equipment is also a critical approach to improving blocking efficiency.
  • DING Jin-hua, ZHANG Wei, SUN Hui, LI Zhao
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 175-179. https://doi.org/10.11988/ckyyb.20190748
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A series of tensile test are carried out for a warp-knitted composite geotextile with high tensile strength composed with polyester filament and polypropylene non-woven geotextile. The effects of width and the initial length on the tensile properties of the geotextile specimen is studied, and furthermore, two different computing methods of tensile strength, wide-width strip method of geotextiles and multi-rib tensile method of geogrids, are compared. Test results show that the wide-width strip method is more suitable than multi-rib tensile method for the calculation of composite geotextile. The tensile strength of composite geotextile is higher with the increasing of specimen width. When the specimen’s width is greater than 100 mm, the strength tends to be stable proximately. In addition, the effect of the initial length of geotextile specimen is not obvious; with the increase of length, the maximum tension force is only slightly lower, but the elongation rate reduces greatly, and the tensile strength corresponding to an elongation rate of 5% is improved greatly. In the tensile test of such geotextiles, the width should be 200 mm, and the initial length should not be less than 300 mm at least.
  • FENG Di, WANG Yuan, GAO Shan, YU Chang-wei
    Journal of Changjiang River Scientific Research Institute. 2019, 36(10): 180-184. https://doi.org/10.11988/ckyyb.20190863
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Despite wide application of vertical anti-seepage reinforcement in embankments, the effectiveness of anti-seepage is difficult to be detected and evaluated after the anti-seepage project is finished due to the complexity of geological conditions and concealment of project. In this paper we analyzed the effects of vertical anti-seepage body, the depth, damage location, and integrity of anti-seepage body on the seepage field of levee by numerical simulation taking the regulation project of diverting Huaihe River into Xinyi River as a case study. We further examined the effectiveness of anti-seepage body by comparing the hydraulic gradient of spill point with the allowable hydraulic gradient of soil. Results show that the head behind the anti-seepage body decreased markedly after the vertical seepage control treatment was carried out on the levee. The bottom of anti-seepage body inserting into the clay layer of levee had better impervious effect than that of anti-seepage body not inserting into clay layer. In the presence of defectives, the infiltration line rose obviously behind the anti-seepage body. The hydraulic gradient in all conditions at the spill point was smaller than the allowable hydraulic gradient, indicating evident seepage control effect.