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Li B.,Changjiang River Scientific Research Institute | Li B.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Gu C.-S.,Hohai University | Wu J.-K.,Hebei University of Engineering
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2013

For the effects of vibration and age, the mechanical parameters of roller compacted concrete dam (RCCD) have gradual change characteristics in space and time, which make a complex variation on the mechanical parameters of RCCD. It is difficult to obtain accurately the mechanical parameters and interface thickness. In this paper, aiming at small difference of elastic modulus and creep among adjacent compacted layers, the determination method of the zone-merged age in RCCD is firstly studied, then considering the gradual change property of RCC in space, the elastic calculation parameter analysis model of typical roller compacted layer is established by using compound material mechanics, and the elastic calculation parameter analysis model of zone-merged body is established using zone-merged algorithm. Finally, on the basis of back analysis of zone-merged equivalent elastic mechanical parameters of RCCD, elastic gradual change parameters of RCCD are solved by using particle swarm optimization algorithm. The engineering example shows that the proposed method is feasible and effective.


Zhang Q.-L.,Changjiang River Scientific Research Institute | Zhang Q.-L.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Wu H.-G.,Wuhan University
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2013

When a steel spiral case is embedded with its top portion covered with a compressible membrane, the membrane is probably responsible for weakening the hold of concrete on the steel spiral case. That may have an influence on the contact between the steel spiral case and the concrete, and even cause a gap between them. First, this paper discussed potential origins of gaps from the view of statics. Then, FEM-based nonlinear numerical simulations were performed to clarify key structural factors influencing the contact state. The results of this study indicate that three structural factors play leading roles in weakening the hold of concrete. They are: (1) a weak friction between a steel spiral case and concrete; (2) a wide membrane-covered range in c-cross-sections and (3) a small compression stiffness of a membrane. However, routine values of parameters concerning the above first two factors do not have significant effect on the contact state. Correspondingly, the contact state is dependent on the third factor mentioned above markedly. In general, therefore, it seems that appropriately reducing a membrane's compression stiffness is a compromise but useful design technique. It will be constructive in ensuring the integrity of a hydropower house substructure.


Zhang Q.,Changjiang River Scientific Research Institute | Zhang Q.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Zhang Q.,Wuhan University | Wu H.,Wuhan University | And 2 more authors.
Yingyong Lixue Xuebao/Chinese Journal of Applied Mechanics | Year: 2011

The engineering has not reached a consensus on how to determine a proper plane covering range of membrane for spiral case in a hydropower station up to now. Four factors including stay ring's displacement and deformation, stay ring's shear capability, generator pedestal's displacement and deformation, flow channel's torsional strength are considered to solve this problem by using three-dimensional finite element method (FEM). The result suggests that if the primary design objective of spiral case structure is to control stay ring and generator The result suggests that if the primary design objective of spiral case structure is to control stay ring and generator pedestal's displacement and deformation, the plane covering end of membrane is suitable to be located between 135° cross section and 180° cross section of spiral case. However, with regard to enhancing stay ring's shear capability and improving flow channel's loading condition, the plane covering end of membrane is suitable to be located between 0° cross section and 90° cross section, or after 270° cross section of spiral case. In view of the fact that the stay ring's shear capability can be enhanced and the flow channel's loading condition can be improved with some specific measures, the stay ring and generator pedestal's nonuniform deformation should take priority when determining the plane covering range of membrane for a spiral case.


Zhang Q.-L.,Changjiang River Scientific Research Institute | Zhang Q.-L.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Wu H.-G.,Wuhan University
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2012

The development in the research and application of spiral case structure with a membrane(SCSM) in hydroelectric power plant, is summarized. It is indicated that SCSM is the trend in development of selecting the embedding type for spiral case. Two significant advances are pointed out: the joint stressing of spiral case and surrounding concrete, the sliding friction between them. The nonlinear mechanical behavior of membrane material as a factor influencing significantly the SCSM research should be considered in the future. The influences of membrane's material and space property on the structural performances of SCSM are respectively stated, and on that basis the existing problems of the SCSM research are concluded. Finally, it is suggested that the of concepte control should be the focus of research in SCSM and the membrane could be regarded as a controlling measure. To explore the theory and measure for controlling the structural performances of spiral case structure from the viewpoint of effect of membrance should be the important topics of research in this field.


Zhang Q.-L.,Changjiang River Scientific Research Institute | Zhang Q.-L.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Li D.-Y.,Changjiang River Scientific Research Institute | Li D.-Y.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | And 2 more authors.
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

In view of the weak knock resistance of concrete face rockfill dam (CFRD), it is essential to determine a rational underwater explosion protection range in front of a dam in the design of anti-terrorism safety protection, underwater monitoring and prewarning. A conventional 100 m-high CFRD was analyzed using Abaqus/Explicit finite element analysis software. The structural damage and the failure of concrete face and their influencing factors were focused on. The dam-foundation-water interaction was considered and the water was simulated using acoustic element. Several explosive distances were supposed with a 10kg-TNT charge underwater explosion in front of the dam. The result shows that different conventional assignments of the three parameters including rockfill's deformation modulus Er, friction factor of vertical and peripheral joints fj and friction factor of contact between concrete face and rockfill fb do not exert an essential influence on the prediction of concrete face's structural failure. It is concluded that the rational underwater explosion protection distance Dp in front of the dam should be determined as 200 m.


Lin S.,Changjiang River Scientific Research Institute | Lin S.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Xie Z.,Changjiang River Scientific Research Institute | Xie Z.,Research Center on Water Engineering Safety and Disaster Prevention of MWR
Journal of Supercomputing | Year: 2016

The General Purpose Graphics Processing Unit (GPGPU or GPU) has powerful float-point computation ability and is suitable for intensive computing, such as solving large linear systems. The Jacobi Preconditioned Conjugate Gradient method (Jacobi_PCG or JPCG), one type of preconditioned iteration methods for the numerical solution of large sparse linear systems, has advantages of high parallelism and is especially appropriate for implementation on GPUs. On multi-GPU cluster, the matrix–vector multiplication involved in the PCG iteration needs the vector entries generated by current GPU and other GPUs, so the communication between GPUs becomes a major performance bottleneck. In this paper, we study the implementation of the JPCG on multi-GPU cluster. Considering the coarse-grained parallelism between GPUs and the sparsity of matrices arising from the finite element method (FEM), a simple and fast node reordering method is presented to optimize the bandwidth of sparse matrices, resulting in a reduction of the communication between GPUs. This novel reordering method is based on integerized nodal coordinates of FEM mesh and the counting sort algorithm. Additionally, computation and communication are overlapped using CUDA asynchronous memory transfer and MPI_sendrecv communication to further reduce the communication cost. A JPCG solver on multi-GPU cluster is developed using CUDA Fortran. Tests show that this solver has high efficiency and strong scalability. © 2016 Springer Science+Business Media New York


Lin S.Z.,Changjiang River Scientific Research Institute | Lin S.Z.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Xie Z.Q.,Changjiang River Scientific Research Institute | Xie Z.Q.,Research Center on Water Engineering Safety and Disaster Prevention of MWR
Science China Technological Sciences | Year: 2015

Discontinuous deformation analysis (DDA) is a numerical method for analyzing the deformation of block system. It employs unified dynamic formulation for both static and dynamic analysis, in which the so-called kinetic damping is adopted for absorbing dynamic energy. The DDA dynamic equations are integrated directly by the constant acceleration algorithm of Newmark family integrators. In order to have an insight into the DDA time integration scheme, the performance of Newmark time integration scheme for dynamic equations with kinetic damping is systematically investigated, formulae of stability, bifurcation, spectral radius, critical kinetic damping and algorithmic damping are presented. Combining with numerical examples, recognition and suggestions of Newmark integration scheme application in the DDA static and dynamic analysis are proposed. © 2015, Science China Press and Springer-Verlag Berlin Heidelberg.


Zhao J.H.,Yangtze River Scientific Research Institute | Zhao J.H.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Liang J.,Yangtze River Scientific Research Institute | Liang J.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | And 2 more authors.
Applied Mechanics and Materials | Year: 2013

In order to resolve the problem of complex wire routing, reliability and lightning-proof difficulty in automatic monitoring system of water conservancy engineering, the paper proposes a volume-compact, easily connected wireless strain collector. The collector modulates the differential strain signal by half-bridge and precise instrumentation amplifier, and employs an up-to-date RF system on chip to realize digitalization for analog voltage signal and wireless transmission. The wireless sensor nodes based on TI's Z-stack protocol possess high performances of network self-organization and network self-healing, and support low power consumption in wireless transmission by sleep mode. © (2013) Trans Tech Publications, Switzerland.


Zhao J.H.,Yangtze River Scientific Research Institute | Zhao J.H.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Ning J.,Yangtze River Scientific Research Institute | Ning J.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | And 3 more authors.
Applied Mechanics and Materials | Year: 2014

It is very significant for hydrological telemetry system to gather such real-time information as rainfall and water level of reservoir in order to improve forecasting level of flood prevention and flood disaster. In this paper, a novel hydrological telemetry system is presented. The system mainly consists of remote terminal units (RTUs) and monitoring center. The RTU is mainly designed to collect rainfall and water level, and send this information to the host computer in the monitoring center by GPRS network or other wireless network. The RTU is completely implemented on a low power consumption hardware platform. The host computer receives the data from the RTUs and analyzes them, then gives detailed tables, diagrams and some decision-making conclusions, which helps the competent authorities of the reservoir or the dam to realize remote monitoring and alarming system. The design principles, difficulties and skills are discussed detailedly in the paper. The low power consumption of the RTU and bit error rate for GPRS communication are both tested. A prototype is developed to validate above design cruces. © (2014) Trans Tech Publications, Switzerland.


Mao S.Y.,Yangtze River Scientific Research Institute | Mao S.Y.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | Zhao J.H.,Yangtze River Scientific Research Institute | Zhao J.H.,Research Center on Water Engineering Safety and Disaster Prevention of MWR | And 2 more authors.
Applied Mechanics and Materials | Year: 2014

Vibrating wire sensor signal acquisition system is widely used in the fields of water conservancy dam, slope, construction, mining and so on to measure osmotic pressure, soil pressure, strain and other physical quantities. This paper studies the single coil vibrating wire sensor signal acquisition system, which uses the STM32F103 core processor generating a low-voltage feedback PWM signal to excite vibrating wire with scanning frequency, after signal amplification, filtering and signal normalization through the frequency measurement module, and ultimately achieve frequency measurement. The system can improve the traditional vibrating wire acquisition instrument, so as to achieve fast and efficient and reliable long-lasting measurement. According to some simulation and designed circuit, the measured data and diagram can verify the feasibility of the method. © (2014) Trans Tech Publications, Switzerland.

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