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. 12 Published: 2018-12-25

	1	Stress-and-strain based failure criterion for concrete
		ZHU He, HU Yu, LI Qingbin
		DOI: 10.11660/slfdxb.20181201
		Concrete failure criterion is a key tool for evaluating the safety of concrete materials and structures. Application of the traditional failure criteria of maximum stress, strain, and energy criterion is limited in the evaluation of the concrete safety of water dams for the long-term coupling effect of mechanical and thermal loads as well as creep relaxation. Hence, a concrete failure criterion for complex sustaining loads should be established. Applying the energy principle, we derive a stress-and-strain based failure criterion for concrete in the general form of Hooke's law. To verify it, we conduct some creep failure tests using concrete specimens and mortar specimens, considering different curing ages, specimen dimensions, and stress levels. Comparing with the traditional criteria, the proposed criterion has a simpler mathematical expression, a clearer physical concept, and is easier to popularize in engineering application.
		2018 Vol. 37 (12): 1-10 [Abstract] ( 272 ) PDF (1430 KB) ( 494 )

	11	InSAR application to deformation monitoring on reservoir bank slopes using COSMO-SkyMed data
		ZHU Mao, SHEN Tiyan, HUANG Song, GE Chunqing, BAI Shujian, HU Qiong
		DOI: 10.11660/slfdxb.20181202
		Deformation monitoring is important for evaluating the stability of reservoir bank slopes. This paper presents an application of PSP-InSAR technology to deformation monitoring on the bank slopes of reservoirs, along with an analysis of the Changlingpi reservoir in Shenzhen using SAR data collected by a COSMO-SkyMed system during 2013-2016. In the analysis, we develop a deformation model applicable to reservoirs with time-varying levels, and make a comprehensive comparison of this model with the traditional model based on InSAR measurements, focusing on their performances in extracting bank slope information. And the deformation response of the area more significantly influenced by the variations of water level is discussed. Then, the accuracy of InSAR measurements is estimated by comparing with corresponding level measurement data, and the characteristics of the two models are further discussed. Results show that our model is capable of mining more deformation information of reservoir bank slopes from InSAR databases.
		2018 Vol. 37 (12): 11-21 [Abstract] ( 246 ) PDF (2478 KB) ( 411 )

	22	Fuzzy risk analysis of dam overtopping under inconsistent snowmelt floods
		CHEN Fulong, ZHANG Xinhou, FENG Ping, HE Xinlin, LONG Aihua
		DOI: 10.11660/slfdxb.20181203
		This study uses Pettitt test and Mann-Kendall test to analyze the inconsistency in the sequence of annual peak flood into the Ken Swart reservoir, conducts consistency correction by the decomposition-synthesis theory, and calculates the fuzzy risk rates of dam overtopping under the conditions of the past and present conditions through risk analysis using the method of the right-angled trapezoidal fuzzy numbers. Results show that in this sequence, a change point occurred in 1993, jumping is its major form of variation, and its overall increasing trend is insignificant. In the present condition, the upper limit estimates of the risk rates at different significant level α are larger than those in the past condition, indicating that the snowmelt floods, affected by the significant increase in temperature over the basin, raise the risk of reservoir failure. The results would help the efficient utilization of flood water resources increasing of flood control benefit, and security of downstream flood protection area.
		2018 Vol. 37 (12): 22-32 [Abstract] ( 187 ) PDF (1830 KB) ( 284 )

	33	Correlation coefficient-based method for grading significance level of periodicity in hydrologic series and its verification
		XIE Ping, ZHAO Yuxi, SANG Yanfang, WU Ziyi, GU Haiting
		DOI: 10.11660/slfdxb.20181204
		A periodic component is one of the time-varying components in an inconsistent hydrologic series, and quantifying and grading its significance level is practically significant. This paper presents a new method that uses the correlation coefficient to grade the significance level of periodicity in a hydrologic series containing only one simple periodic component. It calculates the correlation coefficient between the series and its periodic component, then uses four selected thresholds of this index to grade the corresponding periodicity significance into five levels: no, weak, mid, strong, and very strong. We derive a relationship of correlation coefficient versus half amplitude of periodicity demonstrating the reasonability of the index used in this method, and examine the influence of each variable on the correlation coefficient. Application to synthetic series and observed hydrologic series shows that our method is reliable and effective, thus helping quantify environmental change and its impact on hydrologic variability.
		2018 Vol. 37 (12): 33-43 [Abstract] ( 220 ) PDF (1036 KB) ( 244 )

	44	Optimizing regulation of Jinping II reservoir to reduce sediment deposition using unconventional flood flushing
		LIAN Jijian, JIAN Jiale, XU Kui, RONG Qinbiao
		DOI: 10.11660/slfdxb.20181205
		Severe sediment deposition affects normal operation of reservoirs, but discharging flood water from them in flood season often causes a certain loss of power generation. Aiming at the problem of sediment deposition in reservoirs, this paper designs an unconventional flood-flushing method using reservoir regulation to flush away sediment during unconventional floods. Physical model tests are used to study the trends of sediment transport during symmetrical and asymmetric unconventional floods. Results show that under the symmetrical floods of a fixed average flow rate, the capacity of sediment transport is increased with the increasing flow amplitude, while under the asymmetric floods of fixed average and peak flow rates, it is increased with a decrease in the ratio of base flow duration to peak flow duration. Based on this, we develop a three-dimensional numerical model of hydrodynamics and sediment transport in the Jinping II reservoir, design a reasonable unconventional flood-flushing mode, and verify its effect on sediment flushing and deposition reduction. Thus, unconventional flood flushing is an effective method to reduce sediment deposition in reservoirs, helping save flushing water and achieving economic optimum.
		2018 Vol. 37 (12): 44-53 [Abstract] ( 147 ) PDF (1916 KB) ( 304 )

	54	Advances in research of watershed non-point source pollution models and uncertainty analysis methods
		HAO Gairui, LI Jiake, LI Huai’en, LI Kangbin, YANG Liu
		DOI: 10.11660/slfdxb.20181206
		Non-point source pollution modeling is the most direct and effective way to quantify the pollution of this type. Certain errors generated in the simulation procedure, such as the one in nonpoint source, model structure, model parameters, or data sources, usually cause a large uncertainty in model outputs. This paper summarizes the structure, advantages, and limitations of the representative models of nonpoint source pollution over a watershed, and examines the uncertainties in their calculations, together with an overview on the analysis methods of the uncertainties. From these models’ previous application and existing problems, we suggest that in future modeling accuracy should be improved via adopting a correct procedure: to explore further the non-point source pollution mechanism, and then develop effective reliability models applicable to different data conditions, and combine with soil and water conservation, among other engineering measures. Most previous studies on such uncertainties focused on the uncertainty analysis of single factors, but other analysis methods should also be adopted in future to optimize model structure and find out the best structure for specific problems. And uncertainty methods for multiple systems could be systematically studied to achieve a comprehensive assessment of simulation results.
		2018 Vol. 37 (12): 54-64 [Abstract] ( 301 ) PDF (417 KB) ( 565 )

	65	Hydraulic characteristics of two-stage internal energy dissipators with submerged jet and horizontal swirl flow
		NIU Zhengming, YU Cong, LI Qilong, WANG Tianshi, DENG Yuchen
		DOI: 10.11660/slfdxb.20181207
		This paper describes a new type of two-stage internal energy dissipators with submerged jet and horizontal swirl flow, aiming at cavitation erosion of the discharge tunnel with internal energy dissipators reconstructed from a diversion tunnel, practical engineering difficulties in increasing effective hydraulic head, and limitation on operation modes and flexibility. Basic flow patterns and hydraulic characteristics are measured and analyzed using scale model tests of tunnel dissipators of this type. The results show that the water level in the shaft is a decisive factor to ensure stable operation, and that the entire flow tends to be stable when this level is above 1.2 times the diameter of submerged-jet tunnel. It is affected by the water levels of the tunnel’s inflow and tail flow, with a more significant effect of the former. In the sections of jet orifice and pipe cyclone orifice, the dimensionless flow rates are increased linearly with the increase in relative net effective heads; in the three sections of submerged jet, horizontal swirl flow and vortex diffusion, wall pressure shows a distinct three-stage drops and a stable variation along each section. Under the experimental conditions in this study, the ratios of pressure head drops in the three sections to the tunnel’s working head are 0.12, 0.47 and 0.2 respectively, and the ratios of net effective heads of the two dissipators, i.e. the submerged-jet section and swirl flow section, are in the ranges of 0.13 to 0.15 and 0.59 to 0.80 respectively. And flow velocity around the two orifices is no higher than 26.2 m/s, and average flow velocities at the outlets of the jet section and vortex diffusion section are 10.5 m/s and 14.5 m/s respectively. All this shows that our design of the tunnel is good and reasonable in its two-stage energy dissipation and basic shapes, but much room is still left to improve the tunnel’s working head and further optimize the allocation of dissipated energy to different stages.
		2018 Vol. 37 (12): 65-74 [Abstract] ( 156 ) PDF (1203 KB) ( 269 )

	75	Turbulent characteristics of river channel flow with vegetation patches of different planting densities
		JIAO Junli, WANG Dan, LI Wenqi, YANG Kejun,PENG Qing'e
		DOI: 10.11660/slfdxb.20181208
		A series of flume experiments are conducted to study the influence of vegetation patches of different density on the turbulence intensity of a river channel, using wooden cylinders of the same size distributed uniformly in space to simulate non-submerged rigid vegetation. This paper focuses on analysis of eight sets of different vegetation densities, based on the three-dimensional instantaneous velocities measured using ADV. Comparison and analysis of the measurements reveals that turbulence structure varies greatly across the wake zone downstream of a vegetation patch. Near the downstream edge of the patch, transverse distribution of turbulent energy shows two forms as the density is increasing: one peak at low vegetation density and two peaks on the right and left sides of the patch at high density. Longitudinal distribution behind the patch takes a peak-trough-peak wavy shape, and an increase in vegetation density reduces the spacing of these two peaks that vary in different trends. Turbulence intensity near the downstream edge of the patch increases with vegetation density, and the longitudinal variation in vertical turbulence intensity profiles manifests a trend that the greater the density, the greater its amplitudes. A warping phenomenon in the patch wake can be observed, which is stable in shape when the density is large enough.
		2018 Vol. 37 (12): 75-84 [Abstract] ( 215 ) PDF (423 KB) ( 437 )

	85	Scale allocation of pump stations and layout of channels over reclamation area
		MA Chao, XIA Jinjin, XU Jia, XU Hongshi
		DOI: 10.11660/slfdxb.20181209
		This paper describes a new method for scale allocation of pump stations over the reclamation area to meet the drainage demand, comprehensively considering the characteristics of the river network, flooding process, and the spatial locations of the stations. The relationship of the river network layout and pumping station scales versus the regional characteristics is examined. Application to the Lingang Industrial Zone shows that (1) Compared with the alternative schemes, adoption of this method can effectively reduce the total scale of the pump stations and the frequency of pump opening and closing. (2) There exists an obvious coupling between the river network layout and the regional characteristics: a layout of three horizontal channels and four vertical channels should be adopted in the case of the shape factor exceeding the threshold, and otherwise two horizontal and four vertical channels are optimal. The results would help construct drainage systems for reclamation areas.
		2018 Vol. 37 (12): 85-93 [Abstract] ( 181 ) PDF (665 KB) ( 169 )

	94	Stress-deformation analysis of diaphragm wall in landslide dam based on contact mechanics
		WANG Wei, YIN Yin, PAN Hongwu, ZHANG Bingyin
		DOI: 10.11660/slfdxb.20181210
		Multi-body contact is a strong nonlinear problem. In recent years, computational contact mechanics has been well developed and applied gradually in geotechnical engineering. This paper presents a computational contact mechanics method and its application to 3D stress-deformation analysis of concrete diaphragm walls, along with a case study of the Hongshiyan landslide dam. Results show that this method is capable of handling calculations on a non-conforming mesh and well describing such deformation discontinuities as sliding and separating between a diaphragm wall and its surrounding soil. The calculated stress distribution in the diaphragm wall is reasonable and stable with no exceptional fluctuation or oscillation, implying that the proposed contact mechanics method is effective and applicable to the contact problems of this type.
		2018 Vol. 37 (12): 94-101 [Abstract] ( 229 ) PDF (1100 KB) ( 426 )

	102	Rainwater storage power generating system based on drainage pipeline
		YU Jiaxin, YANG Haosheng, WANG Wen’e, LI Binghui, YANG Kun
		DOI: 10.11660/slfdxb.20181211
		This paper presents a rainwater storage power generating system comprised of a split-flow and purification device and an impounding and generating unit, which is designed to make full use of the potential energy of rainwater collected on building roof. Designed by the siphon principle, it is capable of impounding rainwater in a drainage pipeline, then releasing it to generate power. In analysis of this system, Bernoulli equation is applied to deriving the analytical relationships of its instantaneous velocity, flux, power and time versus water head, and the design is optimized using its instantaneous peak power as the objective function and its peak vacuum as the constraint. We optimize and analyze the geometrical parameters of its siphon η-tube, select 19 sets of tube height parameters first, and then determine the best set of parameter combination (4.5, 6.0) via maximizing the power that is generated through one releasing operation of the water into a unit length of the pipeline. We conduct prototype experimental tests, verify that our power generating system meets design specifications, and develop a formula of the system’s power generation during one cycle of rainwater impounding and releasing. The results of this study, particularly the device and experimental facility, are helpful to rainwater use and further studies on rainwater power generation.
		2018 Vol. 37 (12): 102-111 [Abstract] ( 227 ) PDF (1149 KB) ( 332 )

	112	Denoising swing signals from hydro-electric generating units based on enhanced variational mode decomposition and correlation analysis
		FU Wenlong, LI Xiong, ZOU Zubing, CHEN Tie, TAN Jiawen
		DOI: 10.11660/slfdxb.20181212
		Based on enhanced variational mode decomposition and correlation analysis, this paper develops a novel denoising method for improving analytical accuracy of swing signals generated from hydro-electric generating units with strong noisy background and complicated electromagnetic interference. First, we construct the Hankel matrix of a swing signal and calculate its components via singular value decomposition. Then, we single out an effective singular value using the mean filtering strategy, obtain the Hankel estimation matrix, and inversely reconstruct the signal, thereby achieving an enhancement of those signals in the low band. The signal so reconstructed can be decomposed into a collection of mode components by variational mode decomposition, and thus using autocorrelation analysis, we can calculate the energy focusability indexes of the normalized autocorrelation functions for all its mode components. Finally, by these indexes the effective components are selected and aggregated into a denoised swing signal. Application to denoising the simulated signals and the swing signals measured from a hydro-electric generating unit shows that our method is capable of achieving a good denoising performance.
		2018 Vol. 37 (12): 112-120 [Abstract] ( 171 ) PDF (668 KB) ( 420 )