Volume 13,Issue 3,2015 Table of Contents

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  • 1  Research on flow 2induced vibration characteristics of layered concrete structure
    NIU Chao YANG M in LI Bingyang
    2015, 13(3):268-273.
    [Abstract](1533) [HTML](0) [PDF 1.27 M](3072)
    Abstract:
    Vibration of hydraulic structures caused by flood discharge excitation occurs frequently and has different forms, and serious vibration may lead to structural damage. Few cases of damage caused by vibration for layered concrete structures were presented, and the study of vibration response mechanism was not enough. In this paper, the vibration responses of concrete arch dam with two different structures, including a whole structure and a layered structure, under the same flow discharge conditions were investigated through the comparative analysis of numerical calculation and model test. The relationship between the struc 2 ture and vibration response was analyzed. Furthermore, the relationship between the vibration response of layered concrete structure and flow discharge was studied in consideration of the "beat" concept. The results showed that the beat vibration is mainly caused by the first two bands of vibration with similar frequency. Although the conditions for the formation of beat vi 2 bration may not exist, the vibration curve can present the form of "beat", and the vibration quantity is much large than that of the forced vibration, which indicated that this is actually the hydraulic resonance phenomenon.
    2  Accuracy validation of TRMM precipitation data in Xiang River Basin
    HUANG Ping LU Jing xuan LI De long SONG Wen long QU Wei
    2015, 13(3):401-405.
    [Abstract](1662) [HTML](0) [PDF 819.17 K](3119)
    Abstract:
    The precipitation data predicted by satellite remote sensing technique are widely used, and the accuracy test of precipi 2 tation data is one of the key problems in application. Deviation and correlation analyses are the main methods for the accuracy test of TRMM data, and the accuracy test of different levels of precipitation is lacked. The fuzzy comprehensive evaluation was introduced to perform the accuracy test of different levels of precipitation in the Xiang River Basin. Based on Thiessen polygons method, fuzzy comprehensive evaluation, correlation coefficient method, and scatter points slope method, the accuracy of TRMM 3B42 data at the monthly and daily time scales from 1998 to 2009 was validated using the measured precipitation data at 14 gauge stations. The results showed ( 1) the correlation coefficients of T RMM 3B42 precipitation data reach 0. 93 at monthly time scale and 0. 48 at daily time scale, and the Bias of former data is 84% lower than that of latter data; and ( 2) for different levels of precipitation data, the prediction accuracy of light rain is the best, followed by heavy rain, rainstorm, and moderate rain.
    3  Flood and sediment prediction based on BP neural network
    HE Bin ZHANG Peng hui LIANG Guohua LIU Hao
    2015, 13(3):406-416.
    [Abstract](1903) [HTML](0) [PDF 800.65 K](2963)
    Abstract:
    Knowledge of the impact factors and variation process of river sediments is the key to solve the increasingly serious river sediment problems. In this paper, flood and sediment prediction model was developed to forecast the sediment load based on artificial neural network, which generated promising results. The model was then applied to the Daling River in the northwest of Liaoning Province. First, the data from 29 historicalflood events from 1984 to 1998 were analyzed using the statistical method to obtain the main impact factors of downstream sediment load. Then, the BP neural network model was developed to character2 ize the relationship between the upstream impact factors and downstream sediment load. Finally, the data from six flood events were used to verify the model. The results showed that the errors between the calculated and measured values are within the reasonable range and meet the accuracy requirement, therefore the model is applicable for downstream sediment prediction in the Daling River.
    4  Mine water inflow prediction based on superimposed Markov chain
    LI Jian lin ZAN Mingjun ZHENG Jidong LI Zhi qiang
    2015, 13(3):409-412.
    [Abstract](1609) [HTML](0) [PDF 709.67 K](2928)
    Abstract:
    Superimposed Markov chain was proposed to predict mine water inflow quantitatively since the general Markov chain has limitations. . Based on the water inflow data in the Chengzhuang coal mine from January 2008 to December 2013( 72 months) , water inflow status was classified, state transition matrix was calculated, the predicted values from different step ma 2 trixes were superimposed and averaged, and thus the superimposed Markov chain model was built and the fitting results were analyzed. The water inflow data from January to April 2014 were predicted and compared with the observed data. The results showed that the model prediction accuracy is about 94. 84%, so this new method can be used for mine water inflow prediction.
    5  Determination of flow coefficient at canal head gate in Nanweizi Irrigation District of Dongliao River
    GAO Yujun MEN Bao hui
    2015, 13(3):413-416.
    [Abstract](1294) [HTML](0) [PDF 810.24 K](2847)
    Abstract:
    Accurate determination of gate flow coefficient is very important for the water resources allocation and calculation of the discharge into the irrigation district. Based on the hydrological tests of the canal head in Nanweizi Irrigation District of Gongzhuling City in Jilin Province, we obtained water level and flow data. The relationships between the flow coefficient and wa 2 ter level difference of gate upstream and downstream, flow coefficient and relative opening degree of the gate, and flow coeffi 2 cient and downstream flow were obtained using the statistical calculations. The results showed that flow coefficient is negatively correlated to the water level difference between gate upstream and downstream, whereas flow coefficient is positively correlated to the relative opening degree of the gate and the downstream flow, and all correlation coefficients are above 0. 8.
    6  Research of water resources allocation of Jiangsu intake district of South2to 2North Water Transfer Project
    SONG Dandan YANG Shutan CHANG Ben chun ZENG Chunfen M A Jinsong WANG La chun
    2015, 13(3):417-421.
    [Abstract](1547) [HTML](0) [PDF 796.16 K](3190)
    Abstract:
    On the basis of water resources system analysis and characteristics of hydrology and water conservancy projects, the precipitation and runoff model, hydrodynamic model, water quantity allocation model, and water project scheduling model were constructed to investigate the water resources quantity and water supply and demand in the river basin. Water conservancy pro2 ject scheduling scheme was proposed based on the constructed models and applied to perform reasonable allocation of water re 2 sources in the study area. T he water supply, water demand, and water deficit in agriculture, industry, life, ecology, and lock under the current and planning engineering conditions were simulated, and the corresponding allocation schemes of water resources were established. T hrough the comparison between the current and planning conditions, water supply capacity can increase while water deficit can decrease after the implementation of the first stage of the South2to 2North Water Transfer Project. Under the assurance rates of 95%, 75%, and 50%, annual water deficit rate decreases by 10. 3%, 8. 0%, and 5. 2%, respectively. T he re 2 search can provide scientific reference for the water conservancy project scheduling in the Eastern Route of the South2to 2North Water T ransfer Project, and is of significance for the water resources allocation and scheduling of the inter2basin water conser2 vancy project.
    7  Optimal water operation in Jiangsu section of the South 2to 2North Water Diversion Project
    WANG Wenjie WU Xue wen FANG Guohua WEN Xin
    2015, 13(3):422-426.
    [Abstract](1568) [HTML](0) [PDF 778.51 K](2740)
    Abstract:
    On the basis of the analysis and schematization of the water resource characteristics along the Eastern Route of the South 2to2North Water Diversion Project, a numerical model of optimal water operation in Jiangsu section of the South 2to 2North Water Diversion Project was developed. A new method was proposed based on the improved genetic algorithm, and three work2 ing conditions with different assurance rates were simulated. The results showed that this method can decrease the total water deficit and energy consumption of the system compared to the conventional operation, and allocate the water resources more sci 2 entifically and reasonably. T herefore, the method has a good application value and can provide new idea for the operation man2 agement and real 2time optimal operation of the Eastern Route of the South 2to 2North Water Diversion Project.
    8  Effects of non2point source pollution of nitrogen and phosphorus on water quality of the Yuqiao Reservoir
    GE Ning FENG Ping SUN Dong mei ZHANG Bin LI Fa wen
    2015, 13(3):427-433.
    [Abstract](1319) [HTML](0) [PDF 1.22 M](2795)
    Abstract:
    Yuqiao Reservoir is the unique water source for the water supply of Tianjin City. It. s important to study the effects of the non2point pollution around Yuqiao Reservoir on the water quality in order to improve the water environment and guarantee quality of water supply. Based on the analysis of non2point pollution load, a coupled two2dimensional hydrodynamic and pollutant transport model was developed using the two 2dimensional shallow water and pollutant transport equations. The two 2dimensional model was used to simulate the temporal and spatial distribution characteristics of T N and T P in the reservoir water from June to September in 2008. The simulation results showed that(1)under the effects of inflow of Guo River and dominant wind direc 2 tion in the wet period, T N and TP concentrations diffuse towards the dam site along the south and northwest coastlines, and form the clockwise circumfluence in the east area and the counterclockwise circumfluence in the west area of the reservoir; (2) due to circulation, the water quality in the reservoir center is less affected by the pollution; (3) TP concentration in the east is higher than that in the west of the reservoir, and the average concentration of T P in August is the highest( 1. 56 mg/L); and(4) Liuxiangying and Wubaihu are the main pollution ports of TN, and the average concentration of the T N in September is the highest(3. 74 mg/L).
    9  Assessment of water environment security in Nanchang
    FU Chun ZHAN Shao gui ZHANG Wu hen
    2015, 13(3):434-438.
    [Abstract](1505) [HTML](0) [PDF 702.64 K](2761)
    Abstract:
    Water environment security problems are not only the ecological and environmental problems, but also the social, eco2 nomic, and political issues, which are directly related to the national security and social stability. In this paper, the evaluation in2 dex system of water environment security in Nanchang was developed using the "Driving force2 Pressure2 State2 Response" ( DPSR) model. The weight of each index was calculated using AHP and entropy method, and a comprehensive evaluation of wa 2 ter environment security in Nanchang was conducted using the fuzzy comprehensive evaluation method. T he results showed that the water environment of Nanchang is unsafe in 2012. T herefore, more efforts are needed to improve the water environment se 2 curity, including the environmental investment, pollution emission control, new water source exploration, water 2saving meas2 ures, and improvement on water environment management system.
    10  Risk assessment and control countermeasures of groundwater pollution caused by PTA chemical plant sewage
    YANG Chunxiao LIU Chang li WANG Cuiling
    2015, 13(3):439-443.
    [Abstract](1475) [HTML](0) [PDF 832.32 K](2963)
    Abstract:
    Engineering investigation and a series of experiments, including the static adsorption, biodegradation, and dynamic soil column leaching experiments, were conducted at a PTA chemical plant in Luoyang to determine the solute transport parameters in the vadose zone. The migration of COD Cr in the vadose zone of the sewage reservoir was simulated using Hydrus21D. The re 2 sults showed that (1) it takes 5. 4, 5, 4. 9, and 3. 8 years for COD Cr to migrate from the reservoir bottom to water table under the normal, abnormal, ordinary accident, and risk accident conditions respectively without any anti2seepage measures, and the groundwater pollution risk caused by the sewage reservoir is high; and (2) it takes 12 1 2, 10 1 5, 9 1 1, and 6 1 8 years for COD Cr to migrate from the reservoir bottom to water table under the normal, abnormal, ordinary accident, and risk accident conditions re 2 spectively if there is a 2 152m thick clay layer under the sewage reservoir.
    11  Land use change and its eco 2environmental effects analysis of Middle Route of South2to 2North Water Transfer Project
    GUO Hengliang WEI Yuan yuan HE Xiaohui LU O Qing yuan
    2015, 13(3):444-447.
    [Abstract](1399) [HTML](0) [PDF 814.45 K](2882)
    Abstract:
    Based on the land use data in the Middle Route of South2to 2North Water T ransfer Project(SNWT P) in Henan Prov2 ince, the spatial characteristics of land use change were analyzed, and the eco 2environmental effects of land use in different peri 2 ods at the county scale were investigated. The results indicated that a large area of cultivated land has become the construction land in recent years, but the overall pattern of land use has not changed significantly. Over the whole area, the spatial distribu2 tion of land use change intensity is extremely uneven. In addition, since the construction of Middle Route of SNWTP, the ecolog2 ical environment has improved in general. Key words: land use; Middle Route of SNWT
    12  Phytoplankton diversity and pollution status in main channel of Luanhe River ZHOU Xu 2shen 1 , QI Xiang 2hua 2 , WU Xiao 3 , SUN Feng 1 , SUN Kai 2yan 1 , WANG Yi2zhen 1 , ZHANG Jun 1 , LU
    ZHOU Xu shen QI Xiang hua WU Xiao SUN Feng SUN Kai yan WANG Yizhen ZHANG Jun LUO Yang
    2015, 13(3):448-452.
    [Abstract](1416) [HTML](0) [PDF 807.67 K](2886)
    Abstract:
    The phytoplankton diversity in the Luanhe River was sampled and analyzed in August and October 2011. The results showed that( 1) a total of 99 taxa with 79 genera and 8 phyla are identified, indicating a high diversity of species; (2) the domi 2 nant group is blue 2green algae in the phytoplankton community composition. T he highest proportion of cell density is blue 2green algae, followed by green algae and diatoms; ( 3) Cell density and biomass of phytoplankton have unevenly spatial distribution, and their changes show the same trend along the river. Both values are lower in the upstream but higher in the downstream, in2 dicating a lower level of eutrophication in the upstream while a higher level of eutrophication in the downstream; ( 4) Based on the water pollution analysis using the Pielou index and Simpsen index, the upstream has light level of pollution whereas the downstream has middle level of pollution; and(5) the pollution types of phytoplankton indicators suggest that the pollution indi 2 cator species are higher in October than those in August. T his study provides important reference for the pollution status and a 2 quatic ecosystem restoration in the Luanhe River.
    13  Environmental impact assessment of hydropower project based on ANP2 FCE model
    ZHANG Qing LU Jin xi LIU Zhi qi
    2015, 13(3):453-456.
    [Abstract](1497) [HTML](0) [PDF 844.47 K](2635)
    Abstract:
    T here is interaction between each index in the environmental impact assessment system of the hydropower project. An2 alytic network process( ANP) and fuzzy comprehensive evaluation( FCE) were used to perform the comprehensive evaluation of the environmental impact of hydropower project. First, the network structure model for the environmental impact assessment of hydropower project was developed based on ANP and the weights of all evaluation indexes were determined. T his method over2 comes the disadvantage of not reflecting the interaction between the indexes using the analytic hierarchy process( AHP) . T hen, the theory and method of FCE were introduced to perform the environmental impact assessment of hydropower project, and the ANP2FCE model to evaluate environmental impact of hydropower project was proposed. Finally, the model was applied to a hy2 dropower project in north China and the results suggested the evaluation model is reasonable and effective.
    14  Assessment of water environment quality of Baiyang Lake
    YANG Liwei CHEN Shi yue
    2015, 13(3):457-462.
    [Abstract](2214) [HTML](0) [PDF 722.25 K](6705)
    Abstract:
    The impacts of human activities and dry climate aggravate the water pollution and eutrophication in the Baiyang Lake. Through the analysis of hydro 2chemical compositions of the water, five indexes[Chla, TN, T P, COD Mn, and SD] , which are re 2 lated to water eutrophication, are selected as evaluation parameters, and the comprehensive nutrition index method is adopted to determine the water eutrophication type. T he results of water quality monitoring data show that the type of water is CNaII, and the lake is in mesotrophic or eutrophic state determined by the comprehensive nutrition index method. The principal component analysis results show that TP is the main factor to cause water pollution in the lake. According to the analysis of diatom and its combination, the diatom in the lake is characterized by the combination of eutrophic species Cyclotellameneghiniana ( 20. 43%) and Cyclostep hanos tholif ormis ( 25. 40%) , which indicates that the lake is in the eutrophication state and water environment is in danger.
    15  Multi2objective ecological operation of water supply reservoir
    JIN Xin HAO Cai lian WANG Gang WANG Ling he
    2015, 13(3):463-467.
    [Abstract](1571) [HTML](0) [PDF 781.69 K](2985)
    Abstract:
    A multi 2objective ecological operation model of water supply reservoir was developed according to the runoff character2 istics and practical demand of reservoir operation in North China. T he ecological water requirement of the downstream river was divided into two levels in the model: minimum ecological water requirement and suitable ecological water requirement. The dis2 charge process of reservoir in the low flow period should meet the minimum ecological water requirement in order to sustain the ecological environment in the downstream, and the discharge process of reservoir in the high flow period should meet the suit2 able ecological water requirement in order to provide suitable habitat in the downstream. The multi2objective ecological operation model was applied to optimize the ecological operation in the Shuangfengsi Reservoir using adaptive genetic algorithm. T he re 2 sults showed that the model can provide technical support for the ecological operation of water supply reservoir in North China.
    16  Comparison of concentration variations of phenolic pollutants before and after recuperation and multiplication in the Songhua River
    LI Jian LI Yong liang LI Gui lian JIA Li ming Xudong
    2015, 13(3):468-470.
    [Abstract](1522) [HTML](0) [PDF 734.19 K](2400)
    Abstract:
    Phenolic compounds have some toxicity and are not easy to break down in the natural environment, so they are impor2 tant environmental pollutants. Pollution from the phenolic compounds is severe in the Songhua River before the recuperation and multiplication, and pollution trend shows the existence of polyphenols. Based on the comparative analysis of concentrations of phenolic compounds at seven key sections of the Songhua River in three consecutive years, the recuperation and multiplication measures can reduce the content of polyphenols significantly in the downstream of the Songhua River.
    17  Research on instantaneous flow characteristics of the falling submerged jet in a pool based on PIV technique
    LIU Chao a b LI Longguo a b LI Nai wen a b
    2015, 13(3):471-475.
    [Abstract](1952) [HTML](0) [PDF 1.38 M](2897)
    Abstract:
    In the past, the point measurement techniques, such as laser Doppler velocimetry( LDV) and hot2wire anemometry, or the turbulent flow numerical model with the hypothesis of the isotropy of vortex were used to investigate the turbulent flow field in a pool with an oblique submerged jet. All these methods cannot obtain the refined structure characteristics of the instan2 taneous flow field. The particle image velocimetry(PIV) was adopt to characterize the turbulent flow field in a pool with an ob2 lique submerged jet in term of the velocity, turbulent energy, and flow vorticity. T he results indicated that( 1) the refined struc 2 ture of flow fields with instantaneous and random eddies can be obtained, and the shearing and mixing between the jet and sur2 rounding water decrease the jet velocity and produce turbulent energy and vortex motion, which is the dominant mechanism for jet energy transmission and dissipation in the pool; (2)with the jet plunging into the pool, the flow rate of jet increases along the jet path, while the flow velocity and flow vorticity decrease; ( 3) in the submerged 2jet region, the velocity, turbulent energy, and flow vorticity are approximately in symmetrical distribution. The values of velocity, turbulent energy, and flow vorticity in the jet downstream are a little higher than those in the jet upstream, indicating that the downstream water is more turbulent while the upstream water is relatively stable; and( 4) in the wall 2jet region downstream, the jet continues to shear and mix with the wa 2 ter above to form the flow pattern of a submerged hydraulic jump, and the velocity, turbulent energy, and flow vorticity decrease in both the vertical and horizontal directions.
    18  Determination of soil2water characteristic curve of unsaturated expansive soils using filter paper method
    HUANG Zhi quan YUE Kangxing LI Huan LI Lei
    2015, 13(3):482-486.
    [Abstract](1298) [HTML](0) [PDF 855.92 K](3284)
    Abstract:
    The water content of the soil varies randomly in reality. In this paper, the filter paper method was used to measure the total and matric suction of the unsaturated expansive soil under any cycle path, and the total suction curve and soil 2water charac 2 teristic curve ( SWCC) under any moisture change were obtained. The curve was fitted, and the capillary hysteresis internal vari 2 able model was used to calculate and validate the model applicability for expansive soils through the comparison of test and ob2 served results. Results showed that SWCC determined by the filter paper method is similar to that measured by the traditional methods, and the curve under any change in moisture content does not coincide with the full curve. Under the same moisture content, the smaller the difference between the moisture contents at the starting point of moisture elimination and absorption, the higher the matric suction which is from desorption to moisture, and the lower the matric suction which is from moisture to desorption. Capillary hysteresis internal variable model is suitable for the unsaturated expansive soil, which generates similar re 2 sults with the actual values.
    19  Earthquake 2resistance safety evaluation of overflow section of Qingtianhe masonry gravity dam
    JIAO Yantao a b SHEN Zhenzhong a b ZHOU Guo dong c
    2015, 13(3):487-492.
    [Abstract](1494) [HTML](0) [PDF 1.12 M](2950)
    Abstract:
    According to the engineering geological conditions of Qingtianhe masonry gravity dam, a three 2dimensional finite ele 2 ment model of the overflow dam section was built using the three 2dimensional finite element method. The response spectrum method was used to conduct the seismic response and safety evaluation of the dam. In consideration of the load combinations caused by the seismic loading, the most disadvantaged tensile stress superposition principle was adopted to linearly superpose the static and dynamic calculation results, and the comprehensive static dynamic response was obtained. On the basis, the strength and stability against sliding of the dam were analyzed and evaluated. T he results showed that the strength of the dam meets the standard requirement under the static and dynamic loadings with seismic intensity of level VII; the safety coefficient of stability against sliding of the dam foundation is 3. 47, which is greater than the minimum safety coefficient allowed by the standard; and however, the carrying capacity of dam foundation is insufficient and needs to be reinforced.
    20  Microwave drying characteristics and energy consumption analysis of dredged sediment
    HAN Jiuchun FANG Shenzhu WANG Wen jiang LYU Xiao feng WU Yan
    2015, 13(3):493-496.
    [Abstract](1850) [HTML](0) [PDF 898.79 K](2692)
    Abstract:
    The microwave drying experiments were performed on the dredged sediments with different moisture contents under the microwave output powers of 462, 595, and 700 W respectively. The microwave drying process included increased speed dr2 ying, constant speed drying, and reduced speed drying process. T he results showed that the drying speed, moisture content, and temperature variation of dredged sediment agree with the typical drying characteristics curve. Effects of different factors on the microwave drying characteristics were discussed and unit energy consumption( UEC) was calculated. The initial moisture con2 tent of sediment had little influence on the variation of moisture content, which decreased gently at a lower output power of 462 W and decreased sharply at higher output powers of 595 W and 700 W. T he effects of moisture content and microwave power on the sediment temperature were more obvious during the constant speed and reduced speed periods while not obvious during the increased speed period. U nder the same drying condition, the maximum temperature of sediment was proportional to the micro2 wave power whereas inversely proportional to the moisture content. Compared with infrared drying, microwave drying reduced the drying time significantly. Proper microwave power can reduce U EC by 9% to 26%.
    21  Design of the efficient rotor with low compaction for middle2head wind2driven water pump based on blade element theory and CFD
    GAO Chong heng a ZHENG Yuan b CHENG Xiang a LI Zhong jie a
    2015, 13(3):497-501.
    [Abstract](1309) [HTML](0) [PDF 1015.93 K](2776)
    Abstract:
    In order to reduce the threshold wind velocity of wind2driven water pump and improve the disadvantages of multiple blade, large compaction, and low wind power coefficient in the traditional wind 2driven water pump, the blade element theory was used to design the aerodynamic shape of blades in the wind2driven water pump. The correction factor was introduced, and the chord length and setting angle of the blade were optimized. The CFD method was used to perform numerical simulation of the water pump. The results showed that the designed wind2driven water pump can start at a rate of 215 m/ s under the breeze con2 dition, and the wind power coefficient can reach 0146. The blade has great three 2dimensional flowing characteristics and the air is stable without flow separations under certain condition. The designed wind 2driven water pump advantages of middle head, low compaction, and low starting wind speed, which can expand the scope of wind energy utilization.
    22  Effects of improved Fenton system on dredged sludge dehydration
    TIAN Yu ZHOU Lan WU Yan
    2015, 13(3):502-505.
    [Abstract](917) [HTML](0) [PDF 955.70 K](2518)
    Abstract:
    Fenton system can degrade EPS in the sludge effectively and improve the performance of sludge sedimentation and flocculation. T he traditional technology is not suitable for the sludge of super water retention with high organic and clay con2 tents. In this paper, the effects of improved Fenton system on the dredged sludge dehydration were investigated. T he results showed that ( 1) quick lime has better effects than gypsum and fly ash when the Fenton system is combined with inorganic mod2 ifier; (2) when the quick lime amount is 1%, the SRF of dredged sludge is the lowest with a value of 6. 19@ 10 12 m/kg and the SRF reduction efficiency is 55. 70%; ( 3) sludge dehydration effect is the best when Fenton system is combined with CPAM; and ( 4) when the amount of 0. 1% CPAM is 50 mg/L, the SRF is 0. 83@ 10 11 m/kg and the SRF reduction efficiency is 99. 37%, which is about 91. 54% higher than that treated by Fenton system only.
    23  Numerical simulation of two 2phase flow in centrifugal pump and analysis of fluid2structure interaction of the impeller
    ZHANG cheng XU Sheng yong LYU ZHAO cong ZHOU Difeng HE Siqi
    2015, 13(3):506-509.
    [Abstract](1380) [HTML](0) [PDF 910.33 K](2992)
    Abstract:
    Based on the N2S equation and the traditional k 2E turbulent model, the SIM PLE method was applied to simulate the three 2dimensional solid 2liquid two 2phase flow field in the centrifugal pump. T he distributions of internal pressure and particle concentration were obtained under different concentrations of the solid phase in the centrifugal pump. The structure of centrifu2 gal impeller was analyzed based on the fluid2structure interaction theorem. T he multi 2physical co 2simulation platform ANASYS Workbench was used, and the numerical simulation of centrifugal impeller structure was conducted base on the one 2way fluid 2 structure interaction technology. The equivalent stress and deformation under the different concentrations of the solid phase and same working conditions were determined. The results showed that the volute pressure and solid volume concentration increase with the increasing of spiral radius from the entrance, and the uneven distribution of regional concentration appears at the tongue. Under all the calculation conditions, the variation trends of equivalent stress and total deformation of the impeller are ba 2 sically the same. The stress distribution of the impeller is uneven and local stress concentration occurs. The greater the solids volume concentration, the higher the deformation of centrifugal pump impeller.
    24  Minimum falling 2sill depth of the falling 2sill bottom2flow dissipation
    CUI Zhao a ZHANG Jianrong b ZHANG Qiang
    2015, 13(3):510-513.
    [Abstract](1695) [HTML](0) [PDF 784.25 K](2567)
    Abstract:
    The hydraulic characteristics of the falling2sill bottom2flow energy dissipation pool are affected by the falling 2sill depth. In order to control the allowable maximum time 2averaged dynamic water pressure in the dissipation pool, a method and its theoretic formula for determining the minimum falling2sill depth are preliminarily analyzed and derived using the plane turbulent jet theory. Based on the hydraulic model experiments, the relationship between the time 2averaged dynamic water pressure on the bottom plate and the minimum falling 2sill depth is obtained. T he calculated falling2sill depth is compared with the measured val2 ue to verify the applicability of theoretic formula.
    25  Application of hydrodynamic system of the free 2surface2pressure flow
    WANG Yan chao JIN Sheng LI Na
    2015, 13(3):514-517.
    [Abstract](1289) [HTML](0) [PDF 764.41 K](2732)
    Abstract:
    One2dimensio na l unsteady fr ee2surface2pressur e flow hydrodynamic system is developed which is suit able fo r the long2 distance water diversio n pr oject w ith complex inner boundar ies. Based on the long2distance water div ersio n pro ject w ith open channels and pipes, t he coupled flow sy stem w ith bo th o pen channel flow and pr essure flow is desig ned. In or der to simulate the hy dr aulic characterist ics accurately and analyze t he effects o f fr ee2surface2pressur e flow on t he stability and safet y o f the pro2 ject , Saint Venant equatio ns and Preissmann slit method w ere used to calculat e the pressure flow , fr ee2surf ace flow, and the tran2 sit ion flow, and r eser voirs, pump statio ns, diver sions, culverts, sluices, and other hydraulic structur es w ere added int o t he sys2 tem. The system can so lv e the pr oblems caused by the f ree2sur face2pressure flow in Beijing sect ion of the South2to2No rth Water Diver sion Pr oject.
    26  Numerical simulation of tidal current energy turbine based on CFD
    ZHANG Qiang ZH ENG Yuan CHEN Huix iang
    2015, 13(3):518-521.
    [Abstract](1297) [HTML](0) [PDF 827.70 K](3054)
    Abstract:
    In or der t o dev elo p a hor izo ntal ax is tidal cur rent energ y tur bine w ith hig h hydraulic perfo rmance, thr ee2dimensional numerical simulatio n w as applied to simulate the tidal cur rent energ y turbines using CFD technolog y with FLUENT as the plat2 fo rm. Three different air foil shapes w ere used t o form a total o f eig ht blades of two ty pes, and the flow fields of the turbine pro2 duced by the eight blades were simulated. The results show ed that the tur bine w ith the symmetrical airfo il in the tip o f blade and lar ge2camber air foil in the roo t of blade has bett er hydr aulic perfo rmance. The flow pattern o f the optimal tur bine is g ood and can meet the desig n r equir ements.
    27  Experimental study of impermeability in defect repair bond of concrete
    ZH ANG Xiaona WEN Zhonghua
    2015, 13(3):522-524.
    [Abstract](1322) [HTML](0) [PDF 720.74 K](2732)
    Abstract:
    In or der to pr event the effects o f insufficient impermeabilit y o n the durability of concr ete str ucture in defect repair pro2 jects, experimental impermeability t ests wer e conducted for the bo nding lay er of the new co ncr ete and carbonated old co ncr ete u2 sing five different inter face ag ents. The permeabilit y heights between the new and o ld concrete specimens and the new and old co ncr ete bo nding specimens w ere compa red, the im permeability o f bonding co ncr et e and the effect s of carbonization and inter face agent on the impermeability of new and old bonding concrete wer e analy zed, and the best inter face agent and its mechanism wer e determ ined. The r esults show ed t hat the im permeability o f the new and car bonated co ncr ete and the new and non2carbonated co ncr ete are weaker than that o f t he new and o ld co ncr et e in ontolog y. Mor eo ver , use of silica fume int erface ag ent and water re2 ducing agent can enhance the impermeability o f new and carbonated concr ete compared to that o f the new and non2carbonated co ncr ete, and use of silica fume inter face ag ent can prov ide the best impermeability perfo rmance.
    28  Design of component2based surface water resources al location system
    XU Bina H E Fazhia LIU Panb LI Liping b XIAO Yi
    2015, 13(3):525-529.
    [Abstract](1241) [HTML](0) [PDF 944.45 K](2723)
    Abstract:
    Tr aditional surface w ater r eso ur ces allo cat ion system is usually developed fo r a certa in riv er basin, w hich lacks of ex2 pansibility and flex ibilit y. In this paper, a component2based sur face wat er r eso urces allocatio n system is presented. In the sys2 tem, natur al r iver s, reserv oirs, w ater use po int, and w ater co nnections ar e consider ed as basic compo nents. The system encodes riv ers w ith Ho rto n method, uses to po lo gy so rting and r iver sy nchro nizat ion t o so lv e the hydraulic connections in river netwo rk. Therefor e the r iv er resour ces simulat ion and o pt imization allo cation can be performed using the connecting component s, w hich show s flex ibility , ver satility, and expansibility. T he system can pr ovide technical suppor t fo r water resources management de2 part ment to make plan and design of residentia l w ater use, indust rial pro ductio n, ag ricultur al irr ig ation, and ecolog ical develop2 ment.
    29  Interpolation model of precipitation distribution with el liptic exponential function
    ZH ANG Shengtang ZH ANG Kai
    2015, 13(3):530-533.
    [Abstract](1482) [HTML](0) [PDF 776.60 K](2707)
    Abstract:
    H ow to tr ansform the obser ved po int precipitatio n data at t he pr ecipitation stations into the distr ibuted data required by the hy dr olog ical model is the foundat ion f or the hy dr olog ical process simulation of distributed hydro lo gical model. T he Ellip2 tic Ex ponential Function M odel ( EEFM) has the capability o f identify ing the precipitation center po sitio n and center precipitat i2 o n amo unt. Compar ed w ith other spatial inter po lat ion models, EEFM inter po lation results remain unknow n and need further study. In this paper, Inver se Dist ance Weig hting ( IDW) , Space Linear I nter po lation M odel ( SLIM ) , Revise Inverse Distance Model ( RIDM) , and EEFM w ere a pplied to characterize t he distr ibut ion o f three precipitat ion events in t he Santa Catalina Is2 land. T he inter polat ion results show ed that ( 1) EEFM and RIDM are able to r eflect the pr ecipitation spatial distributio n mor e accurately due to that bo th metho ds consider mor e impact factors and precipitation distributio n char act eristics; ( 2) SLIM con2 siders the data from the t hr ee adjacent points only and ig nor es the effects o f o ther po ints, so its int erpolat ion results show lar ger erro rs compared to o ther models; ( 3) RIDM t akes into account the impact factor of the ups and downs of terr ain elevat ion, and its inter po lation accuracy is better than that of IDW; and ( 4) EEFM is a continuo us dist ribution functio n and it can simulate the co nt inuously spat ial distr ibution trend o f rainfall, therefor e it has a higher accuracy compar ed to o ther three mo dels.
    30  Discussion on concept analysis and construction idea of smart water network engineering
    SH ANG Yizi WANG Jianhua CHEN Kangning LIU M iao ZH AO Yo ng
    2015, 13(3):534-537.
    [Abstract](1418) [HTML](0) [PDF 879.21 K](3079)
    Abstract:
    Smart w ater netwo rk eng ineering includes the w ater phy sical netwo rk const ruct ion which is compo sed of all the w ater regulation infrastr ucture, water info rmation netw ork const ruct ion w hich character izes the intellig ent technolo gy t rend, and w ater manag ement netwo rk constructio n w hich consists of the inst itutional mechanism co nstr uct ion and reg ulatio n decision2making . Smar t w ater netwo rk pro vides the integr ated platfo rm and comprehensiv e suppor t for w ater management and contr ol. There ar e co nt rov ersies in the eng ineer ing co nstr uctio n idea o f smar t w ater netwo rk; however , smart water netw o rk represents the futur e development trend fo r w ater management and has r eceived mor e att ention. In t his paper , the co ncept o f w ater netwo rk eng ineer2 ing is analy zed, w ater netw or k intellectua lizatio n is illustr ated, the constructio n idea of smart water netw ork is discussed, and the cr ucial scientific issues and co re techno lo gy for t he constructio n o f sma rt w ater netwo rk are pro po sed.
    31  Vulnerability assessment of karst water in Feicheng Basin based on COP method
    LIU Hai jiao FAN Mingyuan ZH ANG Baoxiang SH I Yuzhi YANG Xiaofeng ZH ANG Jisheng LIU Dongmei
    2015, 13(3):538-542.
    [Abstract](1352) [HTML](0) [PDF 1.16 M](2575)
    Abstract:
    As t he main w ater supply source and the only drinking water source in the Feicheng Basin, karst gr oundwat er effec2 tively suppor ts t he r apid develo pment of eco nomy and societ y. Based on the analysis o f t opog raphy , g eomo rpho lo gy , and hydro2 g eolog ical conditio ns in t he study ar ea, COP method was used to develop the vulner abilit y assessment model of karst g roundw a2 ter . Results show ed that the vulnerability deg ree is hig h in the bar e Or do vician and Cambrian limesto ne r egio n, the upstream of Kangw ang River , and Chaoquanhe Reser voir. The ev aluation results can prov ide r eferences for the karst gr oundw at er pr otectio n and land use planning in the study ar ea.
    32  Safety monitoring and deformation damage of Dongla landslide in Shuiluo of Muli County
    DONG Jianhui WEI Liangshua i TANG Ran LI Dax in DENG Ren
    2015, 13(3):543-547.
    [Abstract](1319) [HTML](0) [PDF 1.19 M](2511)
    Abstract:
    Dong la landslide in Shuiluo of M uli Co unty is an o ld landslide revival body. Its intensive deformation beg an in 2011 wit h tension cracks ev eryw here, and incr emental defo rmatio n caused lar ge2scale sliding and destruction. Accor ding to the in2situ deformatio n character istics of landslide, surface displacement pier , inclinometer piezometers, and osmomet ers w ere installed to monitor the landslide deformatio n and w ater level var iatio n. Based o n the in2depth ana lysis on the deformat ion and water level monitor ing results, and acco rding to the cumulat ive displacement2 hole depth curv e, slide dislocatio n slip2 time curve, or ifice cu2 mulat ive displacement and r otation azimuth2 time curv e, surface displacement and rotat ion azimuth2 time cur ve, the location and thickness o f a new sliding sur face w ere determined, w hich sugg ested that t he new sliding surface is located in the soil layer of 18. 5 t o 19. 5 m. T he results pr ovided r eliable refer ence fo r the illustr ation of cr eep defo rmatio n of landslide, w hich indicat ed t hat the landslide is currently in the creep defo rmation stag e w ith co nstant speed but can enter into the acceler ated defo rmatio n stag e over time. T he r esea rch summarizes the monito ring results o f the landslide, and is beneficial t o the surv ey desig n, monit or ing , and data analysis of similar landslides.
    33  Groundwater vulnerability assessment in plain area of Hainan Province
    WANG Xiujie FENG Guimin WANG Lina
    2015, 13(3):548-552.
    [Abstract](1137) [HTML](0) [PDF 1.15 M](3011)
    Abstract:
    Groundwater vulnerability assessment in plain area of Hainan Province
    34  Fluorine and arsenic contents in groundwater and their hydrochemical impact factors in Songnen Plain
    ZH U Wei SU Xiaosi T ANG Wen CAI H e
    2015, 13(3):553-556.
    [Abstract](1289) [HTML](0) [PDF 778.90 K](2683)
    Abstract:
    Based on the stat istical dat a o f hydro chemical index es of high2fluo rine and high2arsenic gr oundwater in the study area, 25 g r oups of data wer e selected to identify t he hydro chemical impact facto rs on the f luor ine and ar senic concent ratio ns. The re2 sults show ed that fluo rine and ar senic concentr ations are hig h in the alkaline env iro nment w ith high HCO3 - concentr atio n, flu2 o ride concent ratio n incr eases w ith the increasing of Na / ( Cl + SO4 ) r atio , and TDS in hig h2fluor ine and hig h2a rsenic g roundw a2 ter is also high, indicating the so da process o f the geo log ical setting in the study ar ea. Compared w ith the concentr atio n distribu2 tions of As3+ and As5+ , the analysis o f As3+ and 2 As scatt er plot show ed the distributio n As3+ and As5+ in g ro undwater , w hich sug gested that hig h2arsenic water is mainly in the co nfined aquifer and the main o ver2 standard arsenic ion is As5+ 。
    35  Correlation analysis between geological hazards and impact factors in Qinling2Daba mountains of south Shaanxi Province
    QIANG Fei ZHAO Fasuo DANG Yaqian
    2015, 13(3):557-562.
    [Abstract](1382) [HTML](0) [PDF 738.02 K](2762)
    Abstract:
    Due t o the impact factor s such as climate, hydrolog y, geomorpholog y, geolog ical str ucture, lit ho lo gy , and human activ i2 ties, g eolog ical hazards occur often in Qinling2Daba mo untain a rea. St atistical analysis was per formed o n the geo lo gical hazar d reg ionalization in 28 co unties o r distr icts of south Shaanx i Pro vince, and the distr ibut ion r egular ities of g eolog ical hazards and the relationship betw een geo log ical haza rds and impact factor s w ere inv est igated. T he results show ed that( 1) the g eolo gical haz2 ar ds show banding distributio n along bo th sides of main r iver s, fractures, and ro ads; ( 2) the g eolog ical hazards occur mostly in the ar ea with an aver age annual rainfall less than 1000 mm. The hazar d density decr eases w ith the incr easing of aver age annual rainfall, and the hazard densit y is the g reatest in the a rea w ith an averag e annual rainfall less than 800 mm; ( 3) mo st of the land2 slides o ccur in the slo pes wit h an angle betw een 20 to 40b; ( 4) most of the collapse occur in the slopes w ith an angle between 40 to 60b; ( 5) the g eolo gica l hazards ar e mainly located in the middle and low er mo untain area, and in the litholog ic units o f Devo ni2 an and Proter ozoic eonot hem; ( 6) the effects of fr act ur e on t he g eolo gica l hazar ds on its sides enhance with t he increasing scale of fracture; and( 7) t he haza rd density is t he g reatest in the Feng zhen2Shanyang deep f racture and the area within 1 km to the Baoji2Cheng du r ailw ay. The research results can pro vide scientif ic and r eliable basis fo r the g eolog ical disaster pr evention in mi2 g rat ion relocatio n.
    36  Application of concrete damage plasticity model in the lock design of soft foundation
    SU Chao LIU Cho ngw ei DENG Xibiao LI Jinsong
    2015, 13(3):563-567.
    [Abstract](1237) [HTML](0) [PDF 947.50 K](2661)
    Abstract:
    Acco rding to the basic calculation st ructur e of a ship lock head on the soft foundatio n, a thr ee2dimensional finite ele2 ment model of lock head and foundation was developed using finite element software ABAQUS. The stress distributions of elastic model and elastoplastic model under the same w orking condit ions w ere calculated and analyzed. The tensile stress of the reinforced model was calculated. Finally , the reinfo rcement effects w er e ver ified based on the calculation results and relev ant fo rmula.
    37  Control index of settlement difference after construction of integrated drainage road
    YAN Qiang LIU Baojian SUN Jianx un
    2015, 13(3):568-570.
    [Abstract](1380) [HTML](0) [PDF 695.45 K](2620)
    Abstract:
    In or der to determine the contro l index of sett lement difference r easo nably after the constructio n of integr ated drainag e road, an integ rated dr ainage model of r oad surface w as established using the hydraulic and hy dr olog ic methods. The effects of transverse and longitudinal settlement diff er ences o n the discharg e capabilit y wer e analy zed qualitat ively. T he calculation fo rmu2 las of t he allow able slope var iation r ates in t he transverse and long itudinal dir ections w ere conducted, and the slo pe var iatio n rat e was consider ed as the contr ol index of settlement differ ence of integ rated drainag e road. T he model w as applied to a high level road. The r esults show ed that based on the contro l index of settlement difference o n surface dra inag e, the allow able slope var ia2 tion rates in the t ransv erse and longit udinal directio ns are 0. 76% and 0. 22% , respect ively, and the allow able slo pe var iatio n rat e can be determ ined mor e o bjectively and r easo nably fo r different ar eas and ro ad levels based o n the specific r oad str ucture par am2 eter s and met eo ro lo gical condit ions.
    38  Three2dimensional finite element analysis of cellular diaphragm wall
    SHI Aix iang DENG Xiangji QIU Jianchun LIANG Jiachen DAI Bo
    2015, 13(3):571-574.
    [Abstract](1253) [HTML](0) [PDF 1.03 M](2665)
    Abstract:
    Three2dimensional finite element method w as used t o simulate the ex cavation pro cess o f a foundatio n pit and to analyze the ho rizo ntal displacement and stress distributio n of the cellular diaphr agm wa ll. Finite element so ftw are ABAQUS was used to co nduct the simulat ion. T he r esults show ed t hat t he displacement distr ibution char act eristics of t he cellular diaphr agm w all ar e differ ent f rom tho se o f the g eneral diaphr agm wall with smaller displacement at the w all to p but lar gest displacement at wall bo ttom. The internal and exter na l lo ng itudinal w alls are co nnected thro ug h the par titio n w all, w hich enhances the o vera ll stabili2 ty , and the partit ion wall bears the tension. The r esear ch pro vides t he theor et ic basis for eng ineer ing design, and t he demo nstr a2 tion of safety and stability of the foundation pit eng ineering .
    39  Field experiment and engineering application of cement2modified soil fill ing construction
    SONG Yucai JIAO Jiax un ZHANG Yu li ZHAO Erping
    2015, 13(3):575-579.
    [Abstract](1222) [HTML](0) [PDF 734.44 K](2901)
    Abstract:
    The quality o f cement2modified soil filling constructio n is an im po rtant facto r affecting the stability o f channel slope in the ex pansiv e rock( so il) reg ions. Accor ding to the replacement situation of cement2modified so il in t he South2t o2Nor th Wat er Di2 v ersion Project, a new cement2modified so il filling co nstr uction metho d, concentr atio n f ield mix ing metho d, w as pr oposed based on the analysis o f the field roller com pactio n experiment results of road m ix ing metho d and plant mix ing method. The new meth2 o d can ov ercome the disadvantages of road mix ing metho d and plant mixing metho d, and has been successfully applied to the ce2 ment2modified soil filling co nstr uct ion in t he Middle Route of South2to2Nor th Water Diversion Pro ject, w hich can pr ov ide r efer2 ence fo r the similar eng ineer ing pr ojects.
    40  Key construction techniques of 41 52m thick warehouse layer of Jinping level I super high concrete arch dam
    WANG Jimin DUAN Shaohui ZH ENG Jiang NING Jinhua HU Shuhong
    2015, 13(3):580-584.
    [Abstract](1177) [HTML](0) [PDF 990.88 K](2825)
    Abstract:
    The w arehouse layer thickness of pouring concrete arch dam is o ne of the key factor s affecting the constructio n quality and prog ress. T he breakthro ug h o f the heig ht o f w arehouse layer thickness o f pour ing co ncr ete faces a ser ies o f challeng es inclu2 ding the temperatur e co ntr ol and cr ack preventio n, three height difference contro l, and bo dy contr ol, but it also prov ides the t re2 mendo us pro gr ess and economic benefits for the co nstr uctio n. In this paper, the key const ruction techniques of the 41 52m thick war eho use la yer o f Jinping lev el I super hig h concrete arch dam w ere investig ated. T he research results can pr ovide technical suppo rt fo r similar pr ojects in future.
    41  Construction feasibility of flexible pipe for buried discharge culverts
    ZH ENG Juan LIU Bao jian LIU ChunFeng MA Weisi
    2015, 13(3):585-588.
    [Abstract](1256) [HTML](0) [PDF 781.84 K](2581)
    Abstract:
    Applicatio n of the flex ible pipe to the buried embankment culver t encounters many pr oblems, and determination of the appro pr iate metho d can make it wo rk. In this paper, t he wo rking mechanism of flex ible pipe was int roduced, and the constr uctio n measure o f "Groo ving metho d" was pro po sed. T he r atio nale of the const ruct ion measur e was ex plained, and then the feasibility of the measur e was ver ified throug h the field tests for H DPE w inding reinfor cement pipe. Based on the deformatio n v alues measured by the slide r esistance displacement sensor and the strain dat a measured by the fiber g rating , the defo rmatio n and st rain of t he pipe are minimal and the pipe has no elastic instability after t he construction w ith / Gr oo ving method0, w hich indi2 cated that / Groo ving met ho d0 can develo p the ability of sur ro unding soil and ther efo re the flex ible pipe can be used for bur ied discharg e culvert using this metho d.
    42  Design and improvement of steel liner of Wudongde hydropower station based on ANSYS
    LIAO Xianghui ZH AO Chu DING Ming
    2015, 13(3):589-592.
    [Abstract](1366) [HTML](0) [PDF 837.82 K](2789)
    Abstract:
    According to the structural fo rm of the tr ansit ion o f t he water int ake area in the left diversion tunnel o f Wudong de hy2 dro power stat ion, a larg e hyperbolic steel liner was designed. The static analy sis of the design scheme w as conducted using the finite element softw are ANSYS. T he r esults show ed that the structural stress of the initial design scheme of mo ld is high and the w eig ht is larg e, so the design scheme needs to be impr oved. According to the to po lo gical optim izat ion results based o n WORKBENCH , an impro ved desig n scheme w as pr oposed and verified, which can decrease t he w eight o f mold by 471 0% com2 pared w ith the o riginal scheme. Meanw hile the cost was saved and the stiffness and strengt h of the mold satisfied the construc2 tion requirement. The research results can pr ov ide r eference fo r the similar engineer ing pro jects.
    43  Analysis of the correlation between water consumed structure and industrial structure in different regions of Fujian Province
    ZH ONG Keyuan CHEN Ying CH EN Xingwei LI Xiaocheng
    2015, 13(3):593-596.
    [Abstract](1267) [HTML](0) [PDF 871.66 K](2495)
    Abstract:
    Based on the data of w ater co nsumption structur e and industrial structure in Fujian Pr ov ince between 1998 and 2010, linear reg ression models of the cor relations betw een water co nsumption str ucture and industrial structur e in Fujian Prov ince, in2 cluding the coastal area, mo untainous area, and nine pr efectur es, w ere established using the a pplicat ion o f symmetr ical lo gr atio transformat ion and partial least squar es. The results show ed that the co rr elatio ns between water co nsumption structure and in2 dustr ial st ruct ur e var y in different reg ions of Fujian Pr ov ince. The indust rial w ater co nsumption is hig hly related w ith t he sec2 o ndary industry in the co astal ar ea, w her eas the ir rigation water consumption is hig hly related w ith the pr imar y industr y in the mountaino us ar ea. Water co nsumpt ion is hig hly co rrelated w ith three indust ries in Xiamen, irr ig atio n w ater shows sig nificant co rr elation wit h the primar y industr y in Nanping, Lo ng yan, and Ningde, w hile there is no obvio us cor relat ion betw een w ater co nsumpt ion structure and industr ial st ructur e in Sanming and Zhang zho u.
    44  Discussion on several problems for shear strength of unsaturated soil
    YAO Zhenxing WEI So ng XIAO Shux ia LIU Jiang uo
    2015, 13(3):597-600.
    [Abstract](1314) [HTML](0) [PDF 733.09 K](3439)
    Abstract:
    In v iew o f t he problems in the r esear ch of shear st rength of unsaturated so ils, some r esear ch r esult s of the relat ionship betw een the shear strength and matrix suctio n of unsaturated so il w ere reviewed. Acco rding to the basic pr inciple of unsaturated so il str ess theor y, a new r esea rch v iew po int o f the r elatio nship betw een the vo latile water co ntent and shear st rength of unsatu2 r ated so il w as pro po sed. The effects of the str ess histo ry ( including suctio n histor y) o n the str eng th of unsaturated so il wer e dis2 cussed, and the disadv antag es of contro l suct ion test wer e analyzed. Improv ing the suct ion test techno log y and accur acy of suc2 tion test was consider ed to be one of the impor tant r esear ch directio ns of the st rength character istics o f unsatur ated so il. T he discussion in this paper can benefit the research of unsat ur ated so il str eng th.
    45  Simplified calculation of transverse thermal stress of inverted siphon in winter downtime
    BAI Wenwen JI Richen XU Zhiqiang
    2015, 13(3):601-605.
    [Abstract](1234) [HTML](0) [PDF 777.19 K](2742)
    Abstract:
    The lar ge inv erted siphon in the Middle Route of South2t o2Nor th Water Tr ansfer Pr oject is usually bur ied. In w inter dow ntime, the inner surface bo unda ry conditio n belo ng s t o the third2type boundar y conditio ns. Virtual boundar y was intr oduced to perform the approx imate tr eatment on the third2type bo undary conditio ns, and temper ature field was simplified. Acco rding to the self2balance o f str ess and fo rce metho d, the tr ansv erse no nlinear thermal self2const raint stress and framew or k constraint st ress w ere derived. Integr ation of t he tw o therma l stresses can pro vide the simplified formulas of tr ansv erse thermal stress of inverted sipho n. The formula was applied to Lema River inverted sipho n. The results show ed that dur ing the winter dow ntime, the tensile str ess o f 2 MPa occur s at the inner surface, and the t ensile st ress at the inner surface is larg er w hen the slab thick2 ness is higher, which is unfav or able to thermal stress contro l.
    46  Three2dimensional finite element analysis and reinforcement calculation of segment l ining structure of TBM excavation tunnel
    WANG Xiaojun
    2015, 13(3):606-608.
    [Abstract](1426) [HTML](0) [PDF 940.60 K](2904)
    Abstract:
    In this paper, the pr oblems w hether the segment lining of TBM ex cavation tunnel can sustain the internal pressur e and st ructur e st reng th can meet the desig n requirements under high int ernal water pressure w ere investig ated, and t he effects of seg2 ment lining structure jo int on the over all stress of lining w ere analy zed. , Finite element method was used to dev elo p the thr ee2 dimensional model o f a lo ng2dist ance tunnel at a hy dr opow er st ation. T he results showed that under the internal water pressure, the str ess o f block segment lining is different fr om that o f conventio nal cast2concrete lining, str ess is concent rated at the bo lt co nnection of segment, stress r eleases at t he seam to cause t he decreasing str ess in ot her parts of segment, and the reinfo rcement co ncr ete volume is g reat ly reduced com par ed w ith that of the ov erall cast2in2place co ncr et e.

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