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Zhu Z.,Hydrochina Huadong Engineering Corporation | Qiang S.,Hohai University | Chen W.,Hydrochina Huadong Engineering Corporation
Computers and Concrete | Year: 2013

When using the conventional finite element method, a great number of grid nodes are necessary to describe the large and uneven temperature gradients in the concrete around cooling pipes when calculating the temperature field of mass concrete with cooling pipes. In this paper, the temperature gradient properties of the concrete around a pipe were studied. A new calculation method was developed based on these properties and an explicit iterative algorithm. With a small number of grid nodes, both the temperature distribution along the cooling pipe and the temperature field of the concrete around the water pipe can be correctly calculated with this new method. In conventional computing models, the cooling pipes are regarded as the third boundary condition when solving a model of concrete with plastic pipes, which is an approximate way. At the same time, the corresponding parameters have to be got by expensive experiments and inversion. But in the proposed method, the boundary condition is described strictly, and thus is more reliable and economical. And numerical examples were used to illustrate that this method is accurate, efficient and applicable to the actual engineering. Copyright © 2013 Techno-Press, Ltd.

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.

Zhang C.,Hydrochina Huadong Engineering Corporation | Chen X.,Hydrochina Huadong Engineering Corporation | Hou J.,Hydrochina Huadong Engineering Corporation | Chu W.,Hydrochina Huadong Engineering Corporation
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The axial compression and acoustic emission(AE) tests on T2b marble samples at the depth of 2000 m show that the crack initiation strength equals 0.4-0.5 times UCS(unconfined compression strength); and the crack damage strength approximately equal 0.8 times UCS. The results of T2b marble are similar to the results of Lac du Bonnet granite in URL(underground research laboratory), Canada. The triaxial tests on Jinping marble show a brittle-ductile-plastic transition with increase in confining pressure. A comparison study among T2b marble, Lac du Bonnet granite and Three Gorge granite is carried out to show the difference in post peak mechanical behavior. The brittle-ductile-plastic transition of T2b marble is described by using the constitutive model based on Hoek-Brown strength criterion. The study results are applied to prediction of damage depth in excavation damage zone(EDZ) of diversion tunnels at Jinping II hydropower station.

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.

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.

Sheng S.,Hydrochina Huadong Engineering Corporation
Advanced Materials Research | Year: 2012

Landscape eco-planning is an important approach to keep sustainable development, which can coordinate the relationship between man, nature and resource use. The landscape eco-planning in the future not only must meet the need of landscape's natural function and human, but also need to meet the need of sustainable use of the land. This article discusses the concept, the main principles, procedures and methods of landscape eco-planning, and clarifies the GIS technology in the use of landscape planning and design, in order to play a promote role in the landscape eco-planning in China. © (2012) Trans Tech Publications, Switzerland.

Liu N.,Hydrochina Huadong Engineering Corporation | Zhang C.,Hydrochina Huadong Engineering Corporation | Chu W.,Hydrochina Huadong Engineering Corporation
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

Description on rock basic mechanical behaviour by particle flow code(PFC) starts from contact state among particles and change characteristics. PFC could overcome the difficulties of rock self microscopic behavior and realize the simulation of microscopic structure in rock model. All of those can not be solved by traditional fracture mechanics. The failure of Jinping deep marble is dependent on time. It can be simulated by the parallel-bonded stress corrosion(PSC) model in PFC. A numerical mode for rock that includes time-dependent behavior by adding a damage-raw law to the parallel-bond model is described. Combining with the static-fatigue data of Jinping marble, the microscopic parameters are confirmed in PSC model. The deformation, crack and failure behavior are analyzed in simulation by the test results of PSC under different driving-stress ratios. The results obtained by PFC are coincidence well with the microscopic behavior in rock failure process. The microscopic behavior can help us better to understand the brittle rock strength dependent on time.

Hydrochina Huadong Engineering Corporation | Date: 2012-09-13

The present disclosure relates to a method for sampling rock mass, especially jointed rock mass. The present disclosure provides a simple and convenient method for sampling jointed rock mass to prevent the rock sample from being disturbed and damaged during sampling and accordingly resulting in opening of the weak structural planes, to therefore obtain rock specimen correctly reflecting the basic physical and mechanical characteristics of rock mass comprising integral fissure network. The method for sampling jointed rock mass of the present disclosure comprises the following steps: Step a: Siting; Step b: Drilling; Step c: Protecting; and Step d: Sampling. The method is suitable for determining the basic mechanical properties of the rock mass and for assessing the stability of caverns in jointed rock mass.

Hydrochina Huadong Engineering Corporation | Date: 2012-09-20

A grouting cabin structure of a grouted connection for use in a foundation of an offshore wind turbine generator is described. The structure includes a pile, a sleeve which is coaxial with said pile and installed outside said pile, and a first grouting exhaust port and a first connection port for a grouting pipe provided at an upper part and a lower part of said sleeve. An enclosed cabin of a barrel form is arranged in a gap between said pile and said sleeve, said enclosed cabin is formed by an internal wall of said cabin and said sleeve, a second connection port for the grouting pipe and a second grouting exhaust port are provided at a lower and an upper pat of said enclosed cabin, respectively; the cabin and pile form a first grouting space and said cabin and said sleeve forms a second grouting space.

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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