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Wang H.-L.,Hohai University | Chu W.-J.,Hydrochina Huadong Engineering Corporation | He M.,Jiangsu Transportation Research Institute
Journal of Hydrodynamics | Year: 2012

The rock permeability is an important parameter in the studies of seepage and stress coupling. The micro-cracks and pores can initiate and grow on a small scale and coalesce to form large-scale fractures and faults under compressive stresses, which would change the hydraulic conductivity of the rock, and therefore, the rock permeability. The rock permeability is, therefore, closely related with the micro-cracking growing, coalescence, and macro new fracture formation. This article proposes a conceptual model of rock permeability evolution and a micro kinematics mechanism of micro-cracking on the basis of the basic theory of micromechanics. The applicability of the established model is verified through numerical simulations of in situ tests and laboratory tests. The simulation results show that the model can accurately forecast the peak permeability evolution of brittle rock, and can well describe the macro-experimental phenomenon before the peak permeability evolution of brittle rock on a macro-scale. © 2012 Publishing House for Journal of Hydrodynamics. Source

Liu Q.,Hydrochina Huadong Engineering Corporation
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

After the characteristics of traditional and microcomputer anti-maloperation interlocking are analyzed, the necessity of combining the secondary electric interlocking with the microcomputer anti -maloperation interlocking in the design of hydropower station electric anti-maloperation system is introduced according to the requirements of hydropower station electric "five-preventions" design. The structure of microcomputer anti-maloperation interlocking system is divided into the station control layer, cell layer and process layer and its operating modes are the isolation mode, real-time online mode, hybrid mode, etc. Its interlocking programs and functions are detailed. Practical applications prove its importance in the safe and stable operation of hydropower stations. Source

Yu H.,Hohai University | Yu H.,Henan Polytechnic University | Ruan H.,Hohai University | Chu W.,Hydrochina Huadong Engineering Corporation
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

The deformation and failure characteristics of brittle-ductile-plastic transition, which is shown in the post-peak stage for Jinping deep marble, was simulated by clumped-particle model(CPM) of particle flow code(PFC), and studied from the micro view. After a long process of trial-and-error calibration of laboratory test results, a set of micro parameters for Jinping deep marble were obtained. It is shown that a series of macroscopic mechanical properties of the synthetic rock, including the elastic modulus, Poisson's ratio, uniaxial compressive and crack initiation strengths, stress-strain curves, the peak and residual strength envelops, the ratio of tensile to uniaxial compressive strength, and the failure patterns of synthetic rock samples, all agree well with the test results of Jinping deep marble. Study of regularities of crack development in synthetic rock samples at different confining pressures indicates that: The significant difference of development features of microcracks at different confining pressures is the main reason which leads to Jinping deep marble appearing brittle-ductile-plastic transition character; and the development of large number of tension cracks determines the brittle failure pattern of medium, while the rapid growth of shear cracks prompts the failure patterns of medium transition from brittle to ductile or plastic. Source

Liu N.,Hydrochina Huadong Engineering Corporation
3rd International Joint Conference on Computational Sciences and Optimization, CSO 2010: Theoretical Development and Engineering Practice | Year: 2010

Concrete is first-order diphase multiple materials, and can be regard as harden grout, aggregate and the interface between them. Because of concrete material inner complexity, illegibility, nonlinear and indetermination lead to nonlinear mechanics performance of concrete. Traditional mechanics methods are difficult to apply and have to depend on nonlinear science to set up nonlinear dynamical equation that is fit for itself characteristics. Firstly, the subsystem dynamical equation of concrete is set up based on discontinuous medium mechanics model. Prove the chaos effect when concrete is suffered from the external load. Then combine with the constitutive equation induced by compressor test. Get the curves of displacement and time and phase figures. It is important for the structure safe. According to the subsystem dynamical equation, the parameters can be adjusted by changing stuff graduation, water cement ratio etc. The reliability also can be increased. Finally the concrete dynamical equation under external load is built and found that this equation is a duffin equation. Results show that the concrete material take on complicated response to external load change. © 2010 IEEE. Source

Hydrochina Huadong Engineering Corporation | Date: 2015-03-08

The present invention discloses a connection structure for use in a building for blocking settlement of ground from being transmitted to either a pile foundation or a wall of the building. The connection structure comprises a weight-bearing column, a concrete pile foundation, and an engineering pile connected from top to bottom for bearing weight; the connection structure further comprises a reinforced concrete plate for use as the buildings floor, a wall for the building and a ground beam beneath the wall.

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