Medical Journal of the Chinese People's Armed Police Forces
Home Table of Contents

20 October 2016, Volume 33 Issue 10
    

  • Select all
    |
    RIVER-LAKE SEDIMENTATION AND REGULATION
  • Characteristics of Adjustment in Reach-scale Bankfull Discharge of Yichang-Zhicheng Reach after the TGP Operation
    ZHOU Mei-rong, XIA Jun-qiang, DENG Shan-shan, XU Quan-xi
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 1-5. https://doi.org/10.11988/ckyyb.20150725
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A sharp reduction in sediment load has caused a significant process of channel degradation along the Yichang-Zhicheng Reach after the operation of the Three Gorges Project (TGP), especially in the adjustment of flood discharging capacity. In view of the complicated cross-sectional profiles and the great longitudinal variability in flood discharging capacity, the reach-scale bankfull discharges in the reaches of Yichang and Yidu from 2002 to 2013 were estimated using a combination of geometric average and weighted average method. The effect of channel erosion and deposition on the reach-scale bankfull discharge in each reach was investigated. In addition, empirical relationships were established between the reach-scale bankfull discharge and the previous five-year average fluvial erosion intensity during flood seasons for these two reaches, and it was found that bankful discharge increased with erosion, and decreased with deposition; the correlation between bankful discharge and flow intensity in Yichang was 0.64, whereas in Yidu it was 0.94, indicating that the response of bankfull discharge to the altered flow and sediment regime in the Yidu reach was more remarkable than that in the Yichang reach.
    • WATER RESOURCES AND ENVIRONMENT
  • Water Environment Capacity and Limit Discharge of Pollutants in Tongtian River Basin and the Source Region of Yangtze River
    CHAI Yuan-bing, ZHAO Wei-hua, GUO Wei-jie
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 6-11. https://doi.org/10.11988/ckyyb.20150883
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    :As the origin of the Yangtze River hydrological cycle, the source region of Yangtze River has many important functions of ecosystem services. The changes of water quality and amount together with the unreasonable human activities in the source region have important effects on the sustainable utilization of the water resources in Yangtze River basin. Therefore, researches on the water functions, water environment capacity and control of sewage and pollutant emissions have vital significance for the management of water functional zone. In view of the water quality target of water function area and according to the monitoring data of hydrology and water quality, the pollutart carrying capacity and total limit discharge of pollutants in Tongtian River and the source region of Yangtze River in Qinghai province were studied with the aid of one-dimensional water quality model. Results show that firstly, the pollutant carrying capacity for CODCr and NH3-N of National Nature Reserve of Three Rivers Source was considerably higher than that of other four water function areas including the reserved area of Nieqiaquzhiduo in status year. The pollutant carrying capacity for CODCr and NH3-N of the reserved area of Nieqiaquzhiduo was the highest in planning year. However, the total control amounts for CODCr and NH3-N of the Nieqiaquzhiduo reserved area were higher than those of National Nature Reserve of Three Rivers Source and Chengwenxiqunchengduo reserved area in both status year and planning year. This study could provide theoretical basis for the management of water functional zone and the eco-functional regionalization of the source region of Yangtze River.
  • Numerical Simulation on the Process of Water Quality Influenced by Sudden Pollution Accident of Reservoir
    ZHANG Lin, SUN Juan, ZHAI Jia-jia, YAN Fen-fen, ZHANG Yi
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 12-17. https://doi.org/10.11988/ckyyb.20140746
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    :To prevent from and control the effect of emergent water pollution accident in reservoir area, the temporal and spatial variations of pollutants in the reservoir after the accident were simulated by a 3-D model coupling hydrodynamics and water quality at typical working conditions. Factors of hydrology, meteorology and contaminant movement were taken into account. A large reservoir in the northeastern area of China was taken as a case study. Results revealed that affected by inflow and dominant wind in northeast direction, the contaminants spread toward the direction of the dam site along the southwest coastline, and the area of standard-exceeding contaminants increased gradually; but the concentration of contaminants decreased gradually with the flow process. Through simulation of the water quality, the spatial distribution of contaminants is quantitatively obtained, which offers technical basis for emergency treatment.
  • Comprehensive Evaluation of Water Quality in Dianchi Watershed Based on SSO-PP model
    WU Guang-qiong, FANG Jin-xin
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 18-23. https://doi.org/10.11988/ckyyb.20150696
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to overcome the difficulty of determining the optimal projection direction in practical application of projection pursuit (PP) model, we propose a method of searching the optimal projection direction by using Social Spiders Optimization (SSO) algorithm, and hence building a SSO-PP model of water quality assessment. Four monitoring sections of Dianchi Lake watershed in Yunnan province from 2003 to 2013 were taken as case study. Fiver factors which have big influences on water quality were selected as assessment indicators: NH3-N, TN, CODMn, BOD5, and TP. The rating criteria of water quality were obtained according to index standard thresholds. Results showed that the assessment results of SSO-PP model were consistent with those of single-factor analysis, some superior for section 1#, 2#, and 4#. Kendall statistical test showed that the water quality of section 3# and section 4# improved apparently. The results of SSO-PP model are objective and reasonable, indicating that the model can be applied to assessing water quality effectively.
  • Physical Methods of Removing Biofouling Limnoperna fortunei in Hydraulic Engineering
    WEI Xiao-xi,LIU De-fu,YANG Zheng-jian,ZHANG Jia-lei
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 24-27. https://doi.org/10.11988/ckyyb.20150730
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Hydraulic projects in south China often suffer from the biofouling hazards of limnoperna fortunei which adheres to the surface of structures in high-density, changing the function of structure buildings and affecting the safe operation of hydraulic projects. Through researching the mortality characteristics of limnoperna fortunei under conditions of drying, high water temperature, ultrasound wave, and electric current, we discuss the feasibility of removing limnoperna fortunei using physical methods. Results revealed that limnoperna fortune died three days after being in dehydration condition at 28 ℃; and 10 hours in high temperature (44 ℃) ; when the water temperature is higher than 55 ℃, limnoperna fortunei died instantly contacting with water. Ultrasonic wave and high pressure electric current in water could also kill larva and adult limnoperna fortune effectively. Among the four methods, dehydration and high temperature are the most effective, while ultrasonic wave and electric current are of good prevention effect.
  • Hydro-geochemistry and Geological Genesis of Natural Water in Karst Region in Zhaotong City, Yunnan Province
    LIU Yong-lin, LUO Kun-li
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 28-35. https://doi.org/10.11988/ckyyb.20150718
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Nine river water samples and 27 fissure water samples were collected to study the ion chemistry and geological genesis of natural water in Karst Region in Zhaotong City, Yunnan Province by means of statistical approaches such as Piper trilinear chart, Ion ratio and saturation index method. Results showed that the predominant anion and cation was HCO3-(relative concentration: 67.3% and 70.0%) and Ca2+ (relative concentration: 60.0% and 72.1%), respectively. Total hardness (TH) in 81.7% of natural water from the fluorosis area in Zhaotong was between 75 and 300 mg/L. The F- concentration (mean value 0.1 mg/L) of natural water from the fluorosis area in Zhaotong was well below the standards for drinking water quality (1.0 mg/L). The hydro-chemistry type of fissure water, of which aquifer rock was carbonatite, was Ca-HCO3 and Ca·Mg-HCO3. It is concluded that aquifer lithology controlled the hydro-chemistry of fissure water. High quality water could be found in aquifer rock which is carbonatite and unitary lithology in the fluorosis area of Zhaotong City.
  • Model of Medium-long-term Precipitation Forecasting in Arid Areas Based on PSO and LS-SVM Methods
    MENG Jin-gen
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 36-40. https://doi.org/10.11988/ckyyb.20160010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Precipitation forecasting in arid region is of great significance for water resources utilization and drought disaster reduction. A precipitation forecasting model in yearly and monthly scales based on particle swarm algorithm (PSO) and least squares support vector machine (LSSVM) model was established using the annual precipitation sample of a seven-year cycle and the monthly precipitation sample of seasonal characteristics. The applicability of the model was verified through the measured precipitation sequence from 1960 to 2013 in Altay region. Results show that the model based on PSO and LSSVM could effectively forecast the annual and monthly precipitation in Altay region, hence is of high precision and strong generalization ability. It offers a reliable research idea and method for medium and long-term precipitation forecast in arid areas.
  • Simulation of Monthly Runoff in the Yanhe River Basin Using SWAT Model
    ZHU Ye, FANG Xiu-qin, WANG Kai,ZHU Qiu-an
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 41-45. https://doi.org/10.11988/ckyyb.20150681
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In recent years, SWAT (Soil and Water Assessment Tool) model has achieved good application result in humid south China,but in arid river basins in lack of hydrological data, it has not been widely used. In this research, the semi-arid Yanhe River Basin in Shaanxi Province was taken as an example.In association with GIS and RS technology, a hydrological model based on SWAT model for Yanhe River Basin was built. Data series from 1980 to 1985 were used to calibrate the SWAT model and data from 1986 to 1989 were employed to validate the model. The results are as follows: values of Nash-Sutcliffe coefficient and correlation coefficient are 0.644 and 0.832 respectively in calibration period, and 0.630 and 0.872 in validation period, meeting the requirements of model simulation. The results indicate that SWAT model well reflects the monthly runoff hydrologic process in Yanhe River Basin. The research offers a basis for the further application of SWAT model to river basins in the loess plateau of China.
    • FLOOD PREVENTION AND DISASTER REDUCTION
  • A Mathematical Modeling of Urban Rainstorm Water Logging: Research and Application
    LI Da-ming, HU Yong-wen, WANG Xiao, FAN Li-hong
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 46-50. https://doi.org/10.11988/ckyyb.20150728
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    :To solve the problem of urban rainstorm water logging, a partitioned and stratified calculation pattern is used in the model which is established on the basis of two-dimensional unsteady flow theory and finite volume method improved by hydrologic budget. In view of complicated city water runoff, the model mainly simulates urban community, street, network of drains and river flow. Data of 10 rainfalls from 2009 to 2015 in the demonstration area of Tianjin is used in the model to analyze and compare the water levels of verification points and Jinhe river. Results show that both of the average values differ less than 10 cm, indicating that the model is of precision and can be applied to forecasting urban water logging. It provides a new method and idea for the mathematical modeling of urban rainstorm waterlogging.
    • ENGINEERING SAFETY AND DISASTER PREVENTION
  • Risk Analysis of Liangfengdong Landslide in Wufeng County, Southwest Hubei Province
    XU Yong, LIAN Zhi-peng,LI De-ying,XIE Yuan-hua
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 51-56. https://doi.org/10.11988/ckyyb.20150708
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Risk analysis of individual landslide is a very important content in the field of landslide risk research. Liangfengdong landslide in Wufeng County, Hubei Province was taken as an example to study individual landslide risk. The seepage field and stability change in different rainfall return periods were firstly simulated by Geo-studio software. The vulnerability of building and indoor individual was analyzed by combining qualitative and quantitative analysis. Furthermore, the annual economic risk and individual risk were calculated quantitatively by using exceeding probability method.Finally, risk zoning of individual landslide was also done. The results show that the area of residence affected by landslide was located in extremely high risk zone.The research results could improve the analysis of individual landslide risk, and offer an important reference for the prevention of Liangfengdong landslide.
  • Spatial Distribution of Rockfalls and Landslides in Northern Area of Heishui River Basin in Panzhihua-Xichang Region
    LI Yuan-liang, REN Guang-ming, HUANG Xi-chao,YANG Lei, FAN Rong-quan
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 57-62. https://doi.org/10.11988/ckyyb.20151029
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    :Geological disasters are highly prone to take place in the northern area of Heishui river basin in the Panzhihua-Xichang region. The distribution rules of rockfalls and landslides in the region are researched based on field investigation and high-precision remote sensing image interpretation in association with ArcGIS. The main results are concluded as follows: 1) there are 76 rockfalls and 487 landslides in the study area and 93.4% of the landslides are distributed in slope with gradient of 10°-40°,and 47.4% of the rockfalls are distributed in slope with gradient of 40°-50°; 2) the types and susceptibility of mountain hazard are determined by the combination characteristic and mechanical strength of rock and soil mass in macro scale; 3) at present earthquake activity in the study area is relatively quiet, but faults also have influence on the development of landfalls within a distance of 500m and landslides of 300m, and large-scale landslides and rockfalls usually develop at regions traversed by faults; 4) the distribution of landslides is controlled by river water system in macro sense; 5) roads have influence on the development of landslides within a distance of 300 meters.
    • HYDRAULICS
  • Research and Practice of Pontoon-type Floating Row Applied in Front of Three Gorges Dam to Remove Floating Debris
    CAI Ying, XIE Xue-lun, HUANG Guo-bing
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 63-66. https://doi.org/10.11988/ckyyb.20150674
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Floating debris directly affects hydraulic project’s spillway, power generation, navigation, water quality,and landscape. Floating debris is an environmental problem in engineering, but current approaches could not meet the requirements of large-scale treatment. To improve the passive and inefficient way of treating floating debris, we present an integrated hydraulic approach of treating floating debris by blocking, guiding, and removing debris under the joint action of hydraulics of river and floating row itself. Yangtze River Scientific Research Institute carried out tests using the floating bridge-style row equipped with guiding water power in front of the Three Gorges Dam in flood season of 2014. The floating debris were blocked and guided to a certain location and were removed concentratedly. During the test the facility was proved safe and reliable after going through extreme conditions inclusive of ship collision, waves, water level fluctuation, and counter-terrorism exercises on the water, providing a protective barrier in front of the dam on water surface.
    • ROCK-SOIL ENGINEERING
  • Scale Model Test on the Deformation and Failure Mechanism of Tunnel-type Anchorage Surrounded by Soft Rock
    ZHOU Huo-ming, LI Wei-shu, WANG Shuai, WU Xiang-chao, WANG Zhong-hao
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 67-71. https://doi.org/10.11988/ckyyb.20150832
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To study the failure mechanism and failure mode of tunnel-type anchorage at soft rocks, overloading failure test was conducted through 1∶10 scale field model of tunnel-type anchorage. The surface deformation and internal deformation, the results of borehole inclinometers and the cracks of tunnel-type anchorage model in the overloading process were analyzed. The deformation-load curve and the characteristics of deformation failure of tunnel-type anchorage model under thrust were obtained. Furthermore, the results were comprehensively analyzed in association with numerical simulation results. Research results showed that: similar with the deformation failure of soft rock under loading test, the whole process of the deformation failure of tunnel-type anchorage model experienced three stages. Destructive bottom boundary was formed by tension-shear between the bottom of anchorage and contact area of rocks. Due to upward extrusion, longitudinal tensile cracks of rocks above the anchorage and shear fractures with angle of about 45 degrees to the anchorage were formed. The ultimate bearing capacity of tunnel-type anchorage is mainly decided by the tensile capacity and shear capacity of rocks on the bottom boundary and top of the anchorage.
  • Application of Technology of Advanced Tunnel Seismic Prediction and Its 3D Renderings
    ZHOU Li-ming,QIU Dong-ming,FU Dai-guang,XIAO Guo-qiang,WANG Fa-gang
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 72-78. https://doi.org/10.11988/ckyyb.20160118
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Large-scale safety accidents are prone to be triggered by large geological defectives (broken fault zone, cave, and water gushing and mud) in large hydropower caverns. Advanced geological prediction for hydroelectric tunnel is relatively weak. In this research, the development status and basic principle of TSP (tunnel seismic prediction) technology are firstly introduced, and some key factors that affect TSP data acquisition are discussed. Furthermore, TSP technology is applied to the geological prediction for the discharge tunnels and diversion tunnels of Wudongde Hydropower Station. The geological prediction result of large working face is obtained, and the 3D spatial distribution of the geological defectives is given. The forecast results are basically in accordance with the excavation results which exposed karst caves and water distribution in front of excavation face. The prediction results verify the feasibility and effectiveness of the application of TSP technology in underground engineering of water conservancy and hydropower projects.
  • Factors and Homogeneity of Triaxial Sand Specimens Preparation with Air Pluviation
    CHENG Peng, WANG Yong, LI Xiong-wei, KONG Ling-wei, WANG Yan-li
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 79-83. https://doi.org/10.11988/ckyyb.20160355
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The influences of drop height, funnel diameter and fine particles’ contents on sand specimen preparation for indoor geotechnical triaxial test were studied through preparation test of Fujian standard sand with self-manufactured air pluviation device. Results showed that the relative density of sand specimens increased with the increasing of drop height, and the growth rate slowed down and tended to be stable. The relative density of sand specimens decreased along with the increase of funnel diameter under the same drop height. A wider range of relative density can be achieved with the decrease of funnel diameter. The relative density of sand specimens decreased with the increasing of fine particles’ contents. The influences of drop height, funnel diameter and fine particles’ contents on the relative density of sand specimens can be well explained by Newton’s second law and conservation of energy. The gray image scanned with the 225 kV micro-computerized tomography of sand specimens prepared by air pluviation was analyzed by ImageJ software. The spatial homogeneity of sand specimens can be verified by reconstructing the three-dimensional model of sand specimens and calculating the proportion of sand pore area along the height of sand specimen. Furthermore, reasonable suggestions on preparing triaxial sand specimens were proposed.
  • Sensitivity Analysis of Foundation Pit Rebound in Thick Alluvial Clay Based on Improved Nishihara Model
    WANG Guo-fu, WANG Dan, LU Lin-hai, SUN Jie-cheng
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 84-92. https://doi.org/10.11988/ckyyb.20150941
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The upward displacement of pile and floor is a damage for the balance of support system during the excavation foundation of pit in thick alluvial clay Nishihara model improved with Newton fluid could well describe the behavior of creep deformation during pit excavation,and also trace the behavior of interface between pile and soil.The regularities of upward displacement of floor in the presence of different ratios of inserted pile depth to excavation depth,side lengths and spacings of support pile,as well as the rebound of column pile in the presence of different depths in soil,positions and types of column pile were analyzed via field data,improved Nishihara model and secondary development of FLAC3D.The deep foundation pit of Culture Center of Jinan Province was taken as an engineering background.Results revealed that the sensitivity of the upward displacement of pit floor to different factors follows the order of:distance of adjacent support pile>ratio of inserted depth to excavation depth>length of support pile; and the sensitivity of the rebound of column pile follows the order of depth of column pile in soil>position of pile>shape of plie. The results could be a guidance for reducing the influence of excavation on the upward displacement of pile and floor.
  • A Method of Calculating the Long-term Stability of Slope Reinforced with Anchorage Cable in Consideration of Pre-stress Loss
    DENG Dong-ping, LI Liang
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 93-97. https://doi.org/10.11988/ckyyb.20150747
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In actual project, slope’s long-term stability problem is caused by the loss of pre-stress of anchorage cable acting on the slope due to the creep properties of geotechnical body. To correctly estimate the long-term stability of slope reinforced with pre-stressed anchorage cable, a limit equilibrium calculation method is proposed to analyze slope stability based on the assumption of stresses on the slip surface and by integrating the model of anchorage pre-stress loss. By using this method, the factor of safety of slope reinforced with pre-stressed anchorage cable in different periods are obtained, thus the dynamic change of slope stability can be reflected. By analyzing engineering examples, the feasibility of the method is verified, and the notion that pre-stress loss of anchorage cable worsens the long-term stability of slope is proved. Moreover, parametric analysis on the influence of pre-stress loss of anchorage cable on slope’s long-term stability indicates that increasing the initial pre-stress of anchorage cable is reliable and effective to improving the long-term stability of slope.
  • Analysis and Discussion on Vertical Bearing Capacity of Single Pile in Broken Rock Foundation
    CHEN Jun,WANG Peng-cheng,JI Yong-xin,ZHANG Bin-bin
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 98-101. https://doi.org/10.11988/ckyyb.20150995
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Pile socketed in broken rock is often regarded as end bearing pile with no regard to the side frictional resistance,so that the bearing capacity of pile foundation is not fully utilized. In this research, the vertical bearing capacity of socketed pile in broken rock is analyzed, and the load-bearing performance of pile foundation in broken rock is discussed based on vertical static load test on single pile. The socketed pile of broken foundation rock of a project in Guizhou province is taken as an engineering background. Results show that the side friction of pile segment socketed in rock plays a good role in load-bearing, and the value of side friction varies with different pile components in the same lithology. According to the test results and parameter calculation, the measured vertical bearing capacity of pile foundation is 4.2-5.5 times as high as the calculated value. As we conclude that the side friction of socketed pile in broken rock is remarkable, if it is designed as end-bearing pile, the engineering cost will increase.
  • Fractal Characteristics of Fragments Generated from Rockburst Test on Slate Taken from Jining
    REN Fu-qiang, CHANG Yuan, WANG Dong, CHANG Li-yue, XIA Yuan-yuan
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 102-105. https://doi.org/10.11988/ckyyb.20150742
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to replenish the study of slate’s rockburst test, we carried out indoor rockburst test on slates from Jining by loading in three directions, gradual unloading from one surface, and then vertical gradual loading to simulate the rockburst of slate using deep rockburst simulation test system. Then we collected and screened the rockburst fragments, and calculated the fractal dimensions of fragments of particle size greater than 10mm according to different forms of rock. The results indicate that different forms of rock have influence on the fractal dimension which ranges from 1.62-2.73. The fractal dimensions of length, width, and thickness to quantity have the smallest discrete and can be taken as the preferred indicators. The degree of broken difficulty in thickness, length, width is enhanced gradually. In addition, the fractal dimensions of ratios of length to thickness, length to width and width to thickness could characterize strip, sheet, and block of fragments,respectively. The results of the test indicate that slate rockburst fragments are mainly strip, strip-block and block and the sheet feature of fragments is unobvious.
  • Embedded Depth of Cantilever Pile and Width of Anti-slide Rock Mass in Front of Cantilever Pile
    ZHAO Qing-yuan
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 106-110. https://doi.org/10.11988/ckyyb.20150669
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to spatial limitations, deep excavation of bedrock in front of cantilever pile is needed; besides, a limited width of anti-slide rock is available, which leads to the problem whether the anti-slide rock could guarantee the safety of the cantilever pile. The safe width of anti-slide rock to ensure stability under different embedded depths are discussed through building a computational model of bedrock in front of the pile, and the functional relationship between the width of anti-slide rock and the embedded depth is established with data fitting method. The embedded rock in front of the cantilever pile of a landslide in Yueyang is taken as a case study. Results show that the greater the embedded depth, the smaller the needed width of anti-slide rock to ensure the stability, and they are in a power function relationship hr=16.905 1B-0.754 0. Furthermore, the optimal design parameters of Yueyang landslide is: embedded depth 6.24 m, and width of anti-slide 3.75 m. The results could provide a theoretical guidance and reference for such projects.
    • ROCKSOIL ENGINEERING
  • Optimization of Slope Treatment Schemes Based on Gray Fuzzy Multi-attribute Group Decision Making
    LIU Guang-feng, WANG Lin, ZHOU Ze, XING Qing-song
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 111-115. https://doi.org/10.11988/ckyyb.20150402
    Abstract ( )   Knowledge map   Save
    To curb the common phenomenon that slope treatment schemes are selected unreasonably in practice, a model of optimizing slope treatment schemes based on gray fuzzy multi-attribute group decision-making is proposed through combined application of membership degree, gray degree, multi-attribute decision-making, and group decision-making. The fuzzy, gray, multi-attribute, and group characteristics of slope treatment schemes optimizationprocess as well as five basic goals of safety, quality, cost, time and environment in project construction management are taken as the basis. The slope treatment project from K214+500 to K214+700 of Buka tunnel entrance is taken as a case study to verify the feasibility of the proposed model. Results show that the proposed model is more comprehensive and practical by making full use of invited experts’ advices. It also improves the accuracy of the optimization result.
    • ROCK-SOIL ENGINEERING
  • Optimization of Slope Treatment Schemes Based on Gray Fuzzy Multi-attribute Group Decision Making
    LIU Guang-feng, WANG Lin, ZHOU Ze, XING Qing-song
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 111-115. https://doi.org/10.11988/ckyyb.20150402
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    To curb the common phenomenon that slope treatment schemes are selected unreasonably in practice, a model of optimizing slope treatment schemes based on gray fuzzy multi-attribute group decision-making is proposed through combined application of membership degree, gray degree, multi-attribute decision-making, and group decision-making. The fuzzy, gray, multi-attribute, and group characteristics of slope treatment schemes optimizationprocess as well as five basic goals of safety, quality, cost, time and environment in project construction management are taken as the basis. The slope treatment project from K214+500 to K214+700 of Buka tunnel entrance is taken as a case study to verify the feasibility of the proposed model. Results show that the proposed model is more comprehensive and practical by making full use of invited experts’ advices. It also improves the accuracy of the optimization result.
  • Pore Water Content of Solidified Dredging Silt and Its Distribution Based on Nuclear Magnetic Resonance
    CHENG Fu-zhou, LEI Xue-wen, MENG Qing-shan, CHEN Jie
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 116-120. https://doi.org/10.11988/ckyyb.20150689
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Low field proton nuclear magnetic resonance(NMR) technology is used to measure the distribution of transverse relaxation time T2 of solidified dredging silt soil to study the content and distribution law of pore water in solidified soil. Results show that there is only one main peak in the distribution of relaxation time of solidified soil samples of different cement dosages; the peak area decreases gradually with the growth of curing age and the increase of cement dosage. Pore water content decreases gradually, and the decrease first starts from big pores. The main effect of curing age is reducing the moisture content in the big pores, whereas cement is not only beneficial for reducing the moisture content in the big pores, but also the moisture in the small pores. With the growth of curing age and the increase of cement dosage, the scope of T2 distribution of solidified soil narrows and the distribution tends to short relaxation time, and pore water is distributed in smaller pores gradually. The weighted average relaxation time T2 declines rapidly with the growth of curing age first, and the decline rate decreases gradually after 7 days. Solidified soil’s total nuclear magnetic signal amplitude of T2 shows an overall trend of decrease with the curing age growth, and the speed slows down after 7 days; this is because the water is consumed or converted into mineral water due to internal chemical reaction in solidified soil. Nuclear magnetic resonance(NMR) technology can well present the content and distribution law of pore water in the process of solidification.
  • Numerical Analysis of Lateral Bearing Deformation Behavior of Single Batter Pile with Cap
    FAN Wen-fu,CAO Wei-ping
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 121-125. https://doi.org/10.11988/ckyyb.20150711
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The influence of inclination angle and slenderness ratio, and especially vertical load, on the lateral response of single batter pile with cap was studied through 3-D finite element analysis. Results show that 1) under horizontal load, the lateral deformation of negative batter pile is larger than that of plumb pile, followed by positive batter pile. The difference of lateral deformation between batter pile and plumb pile increases with the increase of the inclination angle. The effect of slenderness ratio on the lateral deformation of batter pile is insignificant under the same condition; 2) the angle of batter pile affects only the value of moment along pile body under horizontal load. The position of the maximum moment of the pile is constant; 3) vertical load is favorable to decrease the lateral deformation of negative batter pile and increase the lateral deformation of positive batter pile; 4) the maximum moment of negative batter pile decreases as the increasing of vertical load, but it is in contrary with the positive batter pile.
  • Experimental Study on Failure Characteristics of Rock Bridge of Different Widths under Direct Shear
    RAN Yao, CHEN Guo-qing, HUANG Bo-rui, ZHANG Xiao-dong, CHEN Cong-shan
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 131-134. https://doi.org/10.11988/ckyyb.20150684
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The failure characteristics of rock mass under different widths of rock bridge and normal stresses were revealed through mechanical model test in association with analyzing the characteristic parameters of acoustic emission during the failure process. Results showed that with the increase of the width of the rock bridge, the fluctuation of failure surface and the roughness of the surface both increased. With the increase of normal stress, the peak shear stress increased continuously but the degree of fluctuation and roughness of the failure surface decreased. The failure modes of rock bridges of different widths under different normal stresses varied, including cutting damage, tensile-shear composite failure, and shear failure.The characteristics of acoustic emission were consistent with the failure process of the rock bridge, and the peak value of AE events, which appeared after the peak of shear stress, increased with the increase of the width of rock bridge and the normal stress.The results provide basis for identifying different destruction stages of rock bridge with different widths.
    • HYDRAULIC STRUCTURE AND MATERIAL
  • Review on the Impact of Hydraulic Vibration on Hydropower Unit and Hydropower House and Vibration Control
    GENG Dan, SONG Zhi-qiang, SU Chen-hui
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 135-139. https://doi.org/10.11988/ckyyb.20160042
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Hydraulic vibration source influences the normal operation of hydropower unit, and induces the vibration of powerhouse. As the most important source among the three vibration sources, hydraulic source distributes widely and affects large areas. Current research on the characteristics of hydraulic source mainly depends on model test which has scale error and is in lack of monitoring points. Also the stability calculation for hydropower unit and power house is excessively simplified. In view of this, a new approach of researching hydraulic source is put forward according to CFD (computational fluid dynamics) numerical simulation. The hydraulic source is converted into incitation on rotational wheel, spiral case and tail water tube to research the stability of unit and power house.
  • Analysis of Dynamic Damage Evolution Translation and a Model of Estimating Damage Value of Concrete under Cyclic Loading and Unloading
    WU Bin, HU Wei-hua, TANG Ke-jing, WEN Pei-jun
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 140-144. https://doi.org/10.11988/ckyyb.20150656
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Concrete samples were tested by multi-function triaxial instrument under cycle load condition with different strain rates. The relationship between acoustic emission signals and stress level was analyzed, and the damage evolution regularity was researched from the aspect of acoustic emission hit number. Furthermore, a single-parameter model that only contains cycle number was established to estimate damage value. The results show that 1) under different strain rates, the paths of damage evolution are not identical. Damage accumulation degree at earlier stage is bigger than that at later stage when the strain is small, and damage curve is flat at later stage; 2) the damage evolution path moves forward with the increase of strain rate, and the value of damage development along with the increase of strain rate presents a regularity that first increases then decreases with the increase of cumulative residual strain. When cumulative residual strain is certain, the damage development degree at two adjacent strain rates weakens with the increase of strain rate; 3) the regularity of concrete damage evolution under cyclic loading and unloading is featured with three phases, which can be reflected by statistical density function.
    • INSTRUMENTATION DEVELOPMENT AND TESTING TECHNIQUES
  • Optimization of Primary Frequency Control Performance of Hydropower Unit
    GAO Xiao-guang, LI Xiao-jun, TANG Ji-qun
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 145-148. https://doi.org/10.11988/ckyyb.20150726
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to meet power grid’s requirement of primary frequency regulation(PFR) of hydropower unit, we analyze the typical problems and influencing factors of PFR, and present a method of optimizing the PFR performance of hydropower unit. The method of optimizing PID parameters of hydraulic turbine governor is analyzed in detail. We propose to adjust the PID parameters according to the range of the deviation, and to change the dead band of the PFR calculation. Furthermore, we put forward some suggestions for PFR and AGC(Automation generator control) coordination control. Power regulation mode used as a priority control mode could guarantee the coordination between PFR and AGC. Through hardware modification and internal program of governor, the PFR performance is optimized and improved. The method is applied to a hydropower unit of 600MW for verification, and the result suggests that the PFR performance is improved.
    • CONSTRUCTION AND MANAGEMENT OF WATER CONSERVANCY PROJECTS
  • Analysis and Quantitative Evaluation of Fatigue Risk in Hydropower Project Construction
    JIANG Xin, XU Ping,JIN Liang-hai, HUANG Hua
    Journal of Changjiang River Scientific Research Institute. 2016, 33(10): 149-154. https://doi.org/10.11988/ckyyb.20151009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the aim of quantifying the evaluation of construction fatigue risk and improving construction safety, a fuzzy comprehensive evaluation method improved by cloud model was proposed to assess the construction fatigue risk of high-risk operationsin hydropower project.Three digital features Ex, En, and He were taken to substitute the comprehensive evaluation matrix and the weight matrix in traditional fuzzy comprehensive evaluation method.Fuzzy membership function was substituted by normal cloud model to calculate the ratings of risk possibility. The evaluation result was visualized by using forward and reverses clouds together.The method was applied to the evaluation of fatigue risk of high slope operations in a hydropower project.Results showed that the fatigue risk level of high slope operations is 5.419, which belongs to moderate risk but obviously closer to big risk. The randomness, fuzziness and subjectivity of the evaluation body are comprehensively considered by using this method.
Office Online
Journal Information
Founded: 1984
Publication Frequency: Monthly
Governing Body: Changjiang Water Resources Commission, Ministry of Water Resources
Sponsor: Changjiang River Scientific Research Institute, Changjiang Water Resources Commission
ISSN 1001-5485
CN 42-1171/TV
Postal Distribution Code: 38-147
Subscription: Available at post offices nationwide
Main column
Visited
    Total visitors:
    Visitors of today:
    Now online:
Copyright © Journal of Changjiang River Scientific Research Institute, All Rights Reserved.
Powered by Beijing Magtech Co. Ltd.