Journal of Hydroelectric Engineering

水力发电学报

Office Online

Included Databases

The journal is included in the following databases:
(i)Scopus,
(ii)The Chinese Science Citation Database Source Journals,
(iii)The Chinese Science Journal Abstract Database,
(iv)The Chinese Science and Technology Papers Statistics and Analysis Database,
(v)China Newspaper Subscription Guide Information Database,
(vi)Chinese Academic Journals (CD).


2018 Vol. 37, No. 5 Published: 2018-05-25

	1	Influence of layer interface on mechanical and permeability properties of mortar
		QIAN Peng, XU Qianjun
		DOI: 10.11660/slfdxb.20180501
		This paper aims at the performance of concrete mortar casted at layer interface by testing tensile splitting strength, ultrasonic pulse, rapid chloride permeability, water permeability, among others. We perform different tests for different intervals between the casting times of upper and lower layers to achieve a better evaluation of the influence of layer interface on the properties of concrete, and observe the microstructure of the layer interface under a scanning electron microscope. The results show that as the casting interval increases, tensile splitting strength and the ultrasonic wave amplitude of first arrival are decreased, but initial electric current and permeability coefficient are increased. The seepage in composite specimens follows the linear Darcy’s model, while in bulk specimens it follows a non-linear model with starting pressure gradient as an additional factor. A very good relationship exists between tensile splitting strength and the amplitude of first arrival. The structures of layer interface are quite different before and after the initial setting time of mortar. When the casting interval is shorter than the initial setting time, hydration products around the interface are almost the same as cement paste, while for long intervals, many interconnected voids and micro-cracks assemble around the interface.
		2018 Vol. 37 (5): 1-12 [Abstract] ( 90 ) PDF (3545 KB) ( 286 )

	13	Three-dimensional analysis of seepage behavior in deep overburden layers with hidden faults
		JIANG Haoyuan, SUN Xinjian, LIU Dongkang, ZHOU Xinjie
		DOI: 10.11660/slfdxb.20180502
		Unfavorable geological conditions such as deep overburden layers and large hidden faults in the Qaidam basin severely affect the seepage stability of the foundation and storage function of a dam. This study examines the cutoff wall measure for reducing seepage flow in a deep overburden layer with hidden faults, and uses a finite element method to analyze the seepage characteristics of this anti-seepage measure and its seepage control effect. Results show that adopting a suspended cutoff wall of 70 m deep, the Wayan reservoir meets the needs of seepage stability and water storage. If the seepage coefficient of a fault is large, the cutoff wall needs to pass through the fault and go deep into the dense rock mass, and its depth into the fault should be determined by combining the seepage flow rate and rock mass compactness. Also, we can decrease the permeability and seepage flow through grouting. For either of these two measures, the cutoff wall should avoid being extended into an interface of two materials widely different in permeability to prevent local erosion under the large hydraulic gradient around its tip, and its safe and stable operation must be ensured.
		2018 Vol. 37 (5): 13-21 [Abstract] ( 119 ) PDF (1184 KB) ( 377 )

	22	Influence of temperature load in gallery outlet sections on arch dam working behavior
		WANG Youle, ZHOU Yihong, ZHAO Chunju, WANG Feng
		DOI: 10.11660/slfdxb.20180503
		A simplified model of temperature and thermal stress fields is solved and verified in this study using steady-state analysis to understand the impact of temperature load in the outlet section of dam galleries on arch dam working behavior under changing environment. In sensibility analysis, we distinguish unfavorable working conditions by different seasons, and find out reasonable measures separately for the conditions of each type according to the uniform design criterion to improve the working behavior. Typical impacts of temperature load are demonstrated through a case study of a super-high arch dam in Southwest China. Results show that the temperature load of this type has a significant impact on dam working behavior and shifts markedly the distribution of temperature and thermal stress in the dam. The working behavior of arch dams can be improved by controlling two sensitivity factors: airflow velocity in the gallery and equivalent heat emission coefficient of the gallery isolating layer.
		2018 Vol. 37 (5): 22-34 [Abstract] ( 127 ) PDF (3461 KB) ( 320 )

	35	Mechanical performance of large eccentric compressive RAC columns under load and chloride
		LUO Surong, LIU Hulin
		DOI: 10.11660/slfdxb.20180504
		To study the mechanical performance of recycled aggregate concrete (RAC) columns under sustained loads and chloride corrosion, we design ten sample columns of large eccentric compressive reinforced RAC and test them using three variables: replacement rate of recycled aggregate, loading strength, and corrosion rate of steel. In the experiment, the columns are electrically corroded under sustained load, and then their bearing capacity and corrosion rate of reinforcement steel bars are measured. And stiffness and ductility are also examined. The results show that the number of rust expansion cracks and the corrosion rate of longitudinal reinforcement both increase with the increase in replacement rate or loading strength. With an increase in replacement rate, stiffness, bearing capacity and ductility decrease, but the varying trends in loading strength are different. A higher corrosion rate results in significantly larger opening of rust expansion cracks and lower stiffness and bearing capacity. When corrosion rate increases, ductility decreases at the corrosion rate greater than 3% while it remains nearly the same at the rate lower than 3% as in the no corrosion cases. The strain distribution over a column section satisfies the plane section assumption. Our measurements of bearing capacity agree well with the calculations obtained using an analytical formula for bearing capacity of corroded reinforced concrete columns.
		2018 Vol. 37 (5): 35-46 [Abstract] ( 123 ) PDF (991 KB) ( 303 )

	47	Bargaining model of allocating incremental benefit from joint operations of multi-stakeholder reservoir system
		XU Bin, MA Yufei, CHU Chenxue, ZHONG Ping’an
		DOI: 10.11660/slfdxb.20180505
		Establishing a fair, efficient and reasonable mechanism of allocating incremental benefit is the key to enhancing optimal joint operations of a multi-reservoir system owned by multiple stakeholders. Based on this principle, an incremental benefit allocation model is developed in this study using the bargaining theory. We derive optimal solutions of the model using the first-order optimality condition, and reveal that the optimal benefit allocation plan meets the conditions of equivalent quasi-slope on each stakeholder’s utility function. Compared to the allocation plans based on the proportional allocation model and Shapley model, the results show that allocation plans of this bargaining model are determined by the interval of each stakeholder’s benefit distribution and the effectiveness of sub-coalition constraints. If the benefit contribution of the sub-coalition is low, the incremental benefit allocated to a stakeholder is positively correlated with its interval of benefit allocation, while when this contribution is high, a high priority will be granted to allocating the excessive benefits of the reservoirs within the sub-coalition. The differences among various methods are generally influenced by how the equality is defined. The incremental benefit allocation plan generated by the bargaining model is highly homogenized to all the reservoirs, and thus ensures the benefit of those weak stakeholders.
		2018 Vol. 37 (5): 47-57 [Abstract] ( 146 ) PDF (1119 KB) ( 240 )

	58	Analysis on changes in flow and sediment at Toudaoguai on Yellow River using range of variability approach
		MA Chao, CUI Ranxin
		DOI: 10.11660/slfdxb.20180506
		This study uses the range of variability approach (RVA) to analyze the data series of average daily runoff and sediment concentration at the Toudaoguai hydrological station on the Yellow River mainstream, focusing on quantitative changes in daily runoff and sediment load caused by the joint operation of Longyangxia and Liujiaxia reservoirs. Changes in the characteristics of synchronous frequencies of monthly runoff and sediment concentration are also evaluated using two-dimensional joint distributions based on the Copula function. Results show that in the period of 1962-2010, runoff and sediment concentration were decreased to a medium extent with the change in runoff relatively more significant. And both were more affected in flood season and annual extreme conditions. In the open flow period of the river, synchronous frequencies of monthly runoff and sediment were increased and were greater than asynchronous ones. This study would help water-sediment joint operation for improving comprehensive benefits of reservoirs.
		2018 Vol. 37 (5): 58-68 [Abstract] ( 151 ) PDF (872 KB) ( 293 )

	69	Estimation of river surface flow velocity through image analysis based on compressed sensing
		WANG Wanliang, QIU Hong, ZHENG Jianwei
		DOI: 10.11660/slfdxb.20180507
		Based on the fundamental principle of feature recognition of water flow images, an emerging non-contact river surface flow velocity estimation method is developed in this study by integrating image acquisition, image pre-processing, implicit mapping between class labels and flow velocity, and data analysis. This method is verified using a group sparse representation classier with feature constraints (GSCFC), a new parameter introduced by the authors for image analysis and estimation of the surface flow velocity of the Jiepai River. And we evaluate GSCFC by conducting comparative experiments with the classical sparse representation based classifier (SRC) and the regularized robust coding classifier (RRC). Results show that GSCFC is a robust discriminative classifier that has an excellent performance for water flow image and outperforms SRC and RRC.
		2018 Vol. 37 (5): 69-79 [Abstract] ( 158 ) PDF (1517 KB) ( 397 )

	80	Variations of stratified density currents in Xiangxi Bay in flood season and cause analysis
		HUANG Yanan, JI Daobin, SHEN Junkun, LIU Defu, WU Qing, WANG Xiong
		DOI: 10.11660/slfdxb.20180508
		Stratified density currents have been existed in Xiangxi Bay for a long time. This study simulates the characteristics of these currents for the period of 2012-2014 using the hydrodynamic and water quality model CE-QUAL-W2, and analyzes their variations, the cause and the risk of algal blooms in the bay through combining the simulations with the data of river runoff and water temperature collected from the section between the Yangtze mainstream and the Xiangxi tributary in flood season. The results show that in the three years of 2012-2014, the depth of the stratified density currents intruding into the bay from the mainstream were varying in the period from the middle to the end of July or the early August, in a typical cycle from middle-upper depth to middle-lower depth and then back to middle-upper depth. The main cause was the increasing mainstream runoff that brought about a change in the trend of mainstream water temperature and then led to a change in the water density difference between the mainstream and the bay. The observed currents evolved lagging behind the increasing of the mainstream flow. A certain variation in water temperature in a corresponding time period is required before it can play a significant role in the formation or evolution of the currents. Generally, the evolution should lower the risk of algal blooms in Xiangxi Bay in flood season.
		2018 Vol. 37 (5): 80-92 [Abstract] ( 118 ) PDF (11935 KB) ( 84 )

	93	Numerical models of local hydrodynamics and sediment transport around river-crossing structures
		CHEN Yixiang, NIU Xiaojing
		DOI: 10.11660/slfdxb.20180509
		Scour around bridge and aqueduct piers is generally considered as a key factor that could probably bring devastating damage to river-crossing structures. Using numerical simulations, we can analyze and forecast the risks caused by such local scours during a flood. This paper describes a system of hydrodynamic and sediment transport models the authors developed, namely HydroCRS, which can be used for calculation of the flow field, sediment transport, and riverbed scour around underwater structures. This model system adopts integration of 1D and 2D models to improve computational efficiency, which also facilitates its connection to hydrological models. Associated with a hydrological model for real-time flood forecasting derived from the weather forecast data, it can achieve the prediction of dangerous scenarios of flows around a river-crossing structure. The model system is applied to simulations of the Shuangji River aqueduct of South-to-North Water Diversion Project, revealing the complicated characteristics of local scour around bridge piers and offering helpful results for the risk management of the aqueduct.
		2018 Vol. 37 (5): 93-99 [Abstract] ( 138 ) PDF (1221 KB) ( 331 )

	100	Formula of bedload sediment transport rate on bed slopes
		WANG Yule, ZHANG Genguang, ZHOU Shuang, CHENG Ye, LI Linlin
		DOI: 10.11660/slfdxb.20180510
		In this work, we study the rate of sediment transport on bed slopes based on the formula of Engelund to derive a theoretical formula of the transport rate with a wide application range. A formula of the probability of sediment incipient motion on bed slopes is also derived through analysis of the forces on a sediment particle on a bed slope and considering the stochastic flow velocity and stochastic position of the sediment particles on the bed. Then, we improve the formulas for calculating the number of sediment particles on a unit area of bed and the velocity of bedload sediment, and obtain a formula of the transport rate of bedload sediment on bed slopes. Results show that our formula feature a high accuracy of calculation and a good applicability to different bed slopes, which is verified by using the measured data of different bed slopes and comparing with the classical formulas.
		2018 Vol. 37 (5): 100-106 [Abstract] ( 155 ) PDF (478 KB) ( 365 )

	107	Simulation of urban rainfall-runoff in piedmont cities: Case study of Jinan city, China
		CHANG Xiaodong, XU Zongxue, ZHAO Gang, LI Huaimin
		DOI: 10.11660/slfdxb.20180511
		During the past decades, frequent flooding disasters in urban areas resulted in catastrophic impacts such as human life casualties and property damages especially in piedmont cities for their specific topography. This study develops a piedmont urban flooding model for the Huangtaiqiao drainage area based on SWMM. The sub-catchments in this study area are divided into mountainous area, plain area and main urban area according to the variations in surface topography. The impact of different routing modes and channel roughness on the simulations is analyzed under different types of scenarios, and a genetic algorithm is used to optimize model parameters. Results show that the simulation is poor (with a mean Nash coefficient of 0.61) when using the traditional routing mode in SWMM model, which usually ignores the difference in surface topography in piedmont areas. However, when the differences in routing modes, percent routed and channel roughness are considered, prediction accuracy is significantly increased (with a mean Nash coefficient of 0.86), indicating the significant affect of the difference in surface topography on the simulations of piedmont cities.
		2018 Vol. 37 (5): 107-116 [Abstract] ( 128 ) PDF (2043 KB) ( 379 )

	117	Rotating stall in centrifugal pump impellers under part-load conditions
		FENG Jianjun, WANG Chen, LUO Xingqi, WU Guangkuan, ZHU Guojun
		DOI: 10.11660/slfdxb.20180512
		Rotating stall is a common unstable flow phenomenon in centrifugal pumps, usually occurring in part-load conditions. It will cause the performance instability of a pump, and even excite the resonance of the whole pump system in certain extreme cases. In this study, stall phenomena in a centrifugal pump under part-load conditions are investigated using CFD method, and the simulated results are compared with experimental measurements, including characteristic curves, internal flow structures, and frequency spectra. A new parameter of the impeller passage, namely blockage coefficient, is adopted to quantitatively evaluate the degree of rotating stall, and the large-scale vortex in a stalled channel is regarded as a stall cell. At the operating flow rate of Q = 0.35Q0 (where Q0 stands for the optional flow rate), five rotating stall cells are observed in the impeller, which propagate among different impeller channels at a rotating frequency lower than that of the impeller. From frequency spectrum analysis, the dominant frequency of these stall cells is about 23.4% of the impeller rotational frequency, or only 4.7% for each stall cell. At Q = 0.41Q0, a stationary stall phenomenon is observed in the impeller passages. In this case, the blockage coefficient of each impeller channel varies slightly during impeller rotation, and thus the stall of this type is relatively stable. Furthermore, the number of impeller blades plays a crucial role in determining the type of stall.
		2018 Vol. 37 (5): 117-124 [Abstract] ( 169 ) PDF (3235 KB) ( 379 )

	125	Theoretical study and experiment on turbine operating characteristics of turbine-fan units
		LI Shihui, LI Yanpin, ZHANG Zichao
		DOI: 10.11660/slfdxb.20180513
		Cooling tower hydraulic turbines, as an important energy saving device in recycling the residual pressure of industrial circulating water system, have been widely used in practice for driving the fan in replacement of motors. Such a turbine-fan unit, with the turbine and fan in series connection, often works at an ultra-low specific speed in a pressured environment, which differs from the conventional power turbines. This paper presents a theoretical study on the working characteristics of a hydraulic turbine in a turbine-fan unit. First, we found that the fan speed is proportional to the turbine flow, namely it is self-adaptive in characteristics ? the speed of the turbine-fan unit is proportional to the flowrate of cooling water, producing the right air flow exactly demanded by cooling water. Second, in the condition of system pressure and flow always changing, the unit speed and unit flow of the turbine are constant, or the turbine always maintains an operating condition of self-similar characteristics. This means that the turbine-fan unit can maintain an optimal working condition if its design condition is well adjusted, different from the power turbine that needs a complicated control on its working conditions. Finally, all these characteristics of working conditions are validated by our experimental results. Thus, such a turbine-fan unit does not need an adjusting system, greatly reducing its construction and operating costs, and the characteristics revealed in this study would be very useful to the design and operation of residual pressure recycling turbines.
		2018 Vol. 37 (5): 125-132 [Abstract] ( 179 ) PDF (651 KB) ( 421 )

	133	Stability of testing techniques for fineness evaluation of different stone powders
		HE Zhen, JIANG Rui, HU Jun
		DOI: 10.11660/slfdxb.20180514
		This study examines various testing techniques for the fineness evaluation of stone powders, including the Blaine air permeation method, negative pressure screen analysis, water flushing filtration method, and laser particle size analysis, focusing on the stability of these techniques based on statistical analysis and SEM images. Results show that the Blaine method is effective and is the most stable method in the fineness evaluation of stone powder. The two sieving methods are simple and easy to achieve, but their test results are usually unstable because the rock lithology and particle surface characteristics has a great impact on stone powder grinding. Results of the laser particle size analysis are in good agreement with those of the Blaine method. This study suggests that the laser analysis should be adopted to characterize particle grading when a high accuracy is required.
		2018 Vol. 37 (5): 133-141 [Abstract] ( 116 ) PDF (1412 KB) ( 251 )

	142	Numerical model of planar fracture grouting based on FVM and VOF
		LI Xiaolong, LUO Xiaoqian, ZHONG Yanhui, ZHANG Bei
		DOI: 10.11660/slfdxb.20180515
		To investigate the mechanism of grout spreading in jointed rocks, a numerical model for simulating planar fracture grouting is developed based on the finite volume method (FVM), the volume of fluid (VOF) method, and collocated grids. This model adopts a momentum interpolation method in its calculation of the flow rate at the control volume faces to avoid the distorted solution of oscillating pressure fields, and considers the two-phase flow characteristic of grout spreading, tracking the moving interface of two phases by VOF calculations. It is tested through application to the grouting in an infinite planar fracture and the results show that its calculations of grouting pressure field distribution, flow velocity and diffusion radius agree well with the analytical solution, thereby verifying a high accuracy in the calculations and laying a basis for developing a dedicated system for fracture grouting simulation.
		2018 Vol. 37 (5): 142-150 [Abstract] ( 201 ) PDF (808 KB) ( 223 )

	151	Automatic rolling system based on closed-loop feedback control and RTK-GPS
		ZHANG Qinglong, LIU Tianyun, LI Qingbin, AN Zaizhan, FAN Lin
		DOI: 10.11660/slfdxb.20180516
		Effective control on the filling and compaction quality of a dam body is the key to ensuring the safety of earth-rock dams. This paper presents an automatic rolling system, based on closed-loop feedback control and RTK-GPS, that can realize the accurate navigation and automatic rolling operation of vibrating rollers. This new system, composed of a remote monitoring device and an onboard automatic navigation control device, works in one of the three modes ? automatic rolling, remote control rolling, and manual rolling, and offers several functions ? wireless communication between equipment, automatic ignition starting, speed regulation, vehicle steering, and braking. It can also achieve an automatic navigation function by planning an overall path and local obstacle-avoiding paths through implementing an A* algorithm together with the RTK-GPS positioning technology. Application to the site compaction of dam construction projects shows that our new rolling system ensures the normal rolling operation in special or emergency situations; solves the problems of rolling omission, cross rolling, and repeated rolling around the joint of two adjacent layers; improves significantly the quality and efficiency of compacting operation. The system, of great application value, can be applied to various earthwork projects in such fields as water conservancy, road, railway, airport, and port engineering. Particularly, it is suitable for filling and rolling operation in dangerous environments or extreme conditions.
		2018 Vol. 37 (5): 151-160 [Abstract] ( 225 ) PDF (1609 KB) ( 311 )