Time filter

Source Type

Zhao S.,South China University of Technology | Zhou X.,South China University of Technology | Zhou X.,POWERCHINA Huadong Engineering Corporation Ltd | Liu W.,South China University of Technology
Granular Matter | Year: 2015

This paper investigated the effect of the particle angularity in light of its importance in angular particle assemblies, using the discrete element method (DEM). A discrete element model with a general contact force law for arbitrarily shaped particles was developed, in which angular particles were modeled using convex polyhedra. Quasi-spherical polyhedral shapes with different vertexes were adopted to reflect the change of angularity. Four categories of assemblies with different angularities were generated. A series of direct shear tests performed on these assemblies were simulated at different vertical stresses. All numerical implementations were achieved using a modified version of the open source DEM code YADE. It was found that the macroscopic shear strength and dilatancy characteristics are in agreement with experimental and numerical results in the literature, indicating that the present numerical model is reasonable. Besides, the evolutions of coordination number, normal contact force distribution, and anisotropies of particle orientation and contact normal were investigated. The results show that the angularity plays a vital role in strengthening the interlocking of angular particles. © 2015 Springer-Verlag Berlin Heidelberg Source

Zhao S.,University of Management and Economics | Huang B.,POWERCHINA Huadong Engineering Corporation Ltd | Guo B.,University of Management and Economics
Communications in Computer and Information Science | Year: 2016

To know whether the water reservoir dredging engineering affect the water source reservoir, Duihekou reservoir is taken as an example in this paper, and a test engineering of dredging at the end of the reservoir is done. First introduced the general situation of reservoir and the test dredging engineering, and combined with the characteristics of reservoir sediment, and onsite monitoring data, the impacts of water quality on the dredging operation of the reservoir, water intake and the test dredging work area were investigated and analyzed. Comprehensive routine monitoring data and special monitoring data, test dredging engineering did not have a significant impact on the water quality of Duihekou reservoir. The water quality of water intake and the test area was not significantly changed. And the upstream tended to improve, through precipitation and water purification treatment. © Springer-Verlag Berlin Heidelberg 2016. Source

Zheng X.Y.,Tsinghua University | Li H.,Dalian University of Technology | Rong W.,Dalian University of Technology | Li W.,POWERCHINA Huadong Engineering Corporation Ltd
Marine Structures | Year: 2015

Offshore wind turbines in regions of active seismicity are under a potential threat caused by the joint earthquake and ocean wave action. Taking NREL-5MW monopile wind turbine as the prototype, this study is devoted to probe the joint action of strong earthquakes and moderate sea conditions. A series of shake table model tests of scale 30:1 have been carried out by the contemporary world unique facility (Earthquake, Wave and Current Joint Simulation System) to investigate the structural response in dry flume, low and high calm water levels, with and without regular or random waves. Particular interest has been in the nacelle acceleration subjected to strong ground motions as well as to random waves. The experimental results of nacelle peak accelerations and corresponding dynamic amplification factors show that the joint earthquake and wave action is important for the proper evaluation of structural response. Ignoring the effect of wave action in seismic analysis will lead to underestimation of structural response, especially when the monopile foundation is dynamically sensitive. The coupling of earthquake and wave actions is sourced not only from the relative velocity of vibration but also from the initial condition induced by waves. It has been also derived that the peak acceleration excited by a moderate sea condition is comparable to that by a moderate earthquake. © 2015 Elsevier Ltd. Source

Cui Z.,CAS Wuhan Institute of Rock and Soil Mechanics | Cui Z.,POWERCHINA Huadong Engineering Corporation Ltd | Sheng Q.,CAS Wuhan Institute of Rock and Soil Mechanics | Leng X.,CAS Wuhan Institute of Rock and Soil Mechanics
Rock Mechanics and Rock Engineering | Year: 2016

In this paper, the seismic stability of the #1 surge chamber of the Baihetan hydropower plant, which is influenced by a large dominating geological discontinuity [the interlayer shear weakness zone (ISWZ) C2)], is studied. An advanced, nonlinear, continuously yielding (CY) model was adopted to describe the complex mechanical properties of ISWZ C2. This model considers a power function type, normal stress dependent behavior and the progressive damage that occurred during shear tests. The applicability of the CY model is proved via a comparison with field test results and the theoretical solution. Verification work was conducted in 3DEC code to show that the 3DEC software is suitable for implementing this model. Three ground motion waveforms were utilized to conduct a seismic analysis of the #1 surge chamber after a special response spectrum matching process. The seismic analysis confirmed the control effect of ISWZ C2 on the seismic stability of the cavern. The majority of the cavern’s seismic displacement consists of elastic body movement, while the plastic deformation is relatively limited. Further, most of the deformations were caused by the contact deformation of C2. For the contact deformation of C2, the magnitude of permanent shear deformation is larger than that of the normal deformation. The magnitude of permanent shear deformation is more notable along the strike direction of C2, and the permanent normal displacement n of C2 mainly occurs along the dip direction of C2. Finally, the seismic stability of the cavern is assessed via the overload method. The seismic safety factor of the cavern is approximately 2–3. © 2016 Springer-Verlag Wien Source


Disclosed is a wind turbine generator foundation with pressure-dispersive pre-stressed anchor rods or anchor ropes. The foundation comprises a pile cap, a plurality of foundation piles arranged circumferentially at the bottom of the pile cap at uniform spacing, and a wind turbine generator tower connected to an upper part of the pile cap.

Discover hidden collaborations