POWERCHINA Huadong Engineering Corporation Ltd
POWERCHINA Huadong Engineering Corporation Ltd
POWERCHINA HUADONG ENGINEERING CORPORATION Ltd | Date: 2016-08-22
The present invention relates to a cofferdam deformation-adaptive impervious composite geomembrane structure and construction method thereof, which applies mainly to high rockfill cofferdam, earth and rockfill dam and the like employing composite geomembranes for seepage control in hydraulic and hydro-power engineering. The cofferdam deformation-adaptive impervious composite geomembrane structure and construction method according to the present invention can reduce damage degree of the connections between the composite geomembranes and the concrete toe slabs or the joints between the composite geomembranes and the concrete caps on the top of the concrete impervious walls.
He B.,Zhejiang University |
He B.,Power China Hua Dong Engineering Corporation Ltd |
Wang L.,Zhejiang University |
Hong Y.,Zhejiang University
Acta Geotechnica | Year: 2017
Piles supporting transmission towers, offshore structures (such as wind turbines), or infrastructures in seismic areas are frequently subjected to either one-way or two-way cyclic lateral loadings. Relatively little attention, however, has been paid to compare and understand the effects of different loading regimes (one-way or two-way cycling) on lateral responses of piles in soft clay. For this reason, a series of field tests in soft clay are carried out to compare one-way and two-way cyclic responses of single piles and of jet-grouting reinforced piles. The field tests reveal that the single pile subjected to two-way cycling experiences much more rapid degradation in lateral stiffness and capacity, but accumulates much smaller residual pile deflection (δp), than the single pile under one-way cycling. This is because the reverse part of the two-way cycling also generates plastic strain, causing additional softening and strength reduction in the soil surrounding the pile. After each cycling, non-zero bending moment (i.e. locked in moment, or ML) is retained in the single piles, and the ML increases with the δp. The one-way cycling leads to two times larger ML than the two-way cycling, as it causes greater δp. The maximum ML in the pile after one-way cycling can be up to 40% of the maximum bending moment induced during the previous cyclic loading stage. After application of jet-grouting surrounding the upper part of the single pile, it greatly reduces degradation of lateral pile stiffness, accumulation of δp and therefore development of ML. Compared to the field measurements, the API (API RP 2A-WSD, recommended practice for planning, designing, and constructing fixed offshore platform-working stress design, 21st edn. API, Washington, 2000) code underestimates the lateral stiffness of the pile under one-way cycling, while overestimates that of the pile under two-way cycling, leading to a non-conservative prediction of bending moment in the latter pile. © 2017 Springer-Verlag Berlin Heidelberg
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
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2017
Near-fault ground motion mechanisms have seldom been assessed in the seismic studies of underground rock caverns, especially the caverns controlled by large geological discontinuities. A nonlinear joint model was adopted to simulate the unfavorable geological discontinuities. The near-fault pulse-type, near-fault non-pulse-type and far-field ground motion records collected from the NGA-West2 database were used to analyze the influence of near-fault ground motions on unfavorable geological discontinuities. A damage potential index (DPI) was discussed and proposed for unfavorable geological discontinuities. The surge chamber #1 of the Baihetan hydropower plant, which is controlled by the interlayer shear weakness zone (ISWZ) C2, was used as a case study to investigate the differences between the pulse-type near-fault ground motion, non-pulse-type near-fault ground motion and far field ground motion. The significant velocity and displacement and the higher long-period response spectrum were found to associate with the pulse-type near-fault ground motion, while the non-pulse-type near-fault ground motions displayed the similar characteristics as the far field ground motions. The velocity pulse is responsible for the destructive capabilities of near fault ground motions, which may cause the unacceptable sliding along the discontinuity, leading to potential cavern failure. In comparison with several ground motion parameters, PGV was shown to be the most suitable DPI for large geological discontinuities under the earthquake excitation, which was true for both the near-fault and far-field ground motions. PGV was verified to be an effective DPI via the seismic analysis of the Baihetan surge chamber #1.The cavern becomes fragile when subjected to the near-fault ground motions. Therefore, the special seismic reinforcement measures are recommended. These findings may provide a reference for the seismic design of underground caverns. © 2017, Science Press. All right reserved.
Tian H.,Power China Huadong Engineering Corporation Ltd
Modern Tunnelling Technology | Year: 2017
Based on the design practice of subway engineering, this paper summarizes the design schemes for shield arrival shaft combined with the mined station. Through a comprehensive consideration of factors such as shield hoisting, air duct construction, running tunnel construction, station construction, air duct layout, etc., this paper analyzes the advantages and disadvantages of various schemes and their adaptabilities. Additionally, a scheme is recommended for hoisting a shield out of a shaft by making use of the mined underground shaft, air duct and air shaft considering that it is not possible to set up a separate shaft around a mined station. Through design calculation, the design technology for a large shaft is summarized. The results show that traffic condition, construction period and station form are the main influencing factors for setting a shield arrval shaft, and it is feasible to construct a shield arrival shaft in combination with a station air duct. © 2017, Editorial Office of "Modern Tunnelling Technology". All right reserved.
Yang Q.,Zhejiang University |
Fang X.,Zhejiang University |
Fang X.,Powerchina Huadong Engineering Corporation Ltd |
Fang X.,Hangzhou Electric Power
IET Generation, Transmission and Distribution | Year: 2017
With the increasing penetration of small-scale distributed generators (DGs) and storage units into the domestic areas and the emergence of real-time pricing (RTP) of electricity, residents have more opportunities to obtain a cost-effective energy management through the participation of demand side management. Unlike existing online solutions, this paper presents an alternative one-day-ahead energy dispatch solution to achieve the economic benefits of meeting the demand with minimised electricity purchase cost by optimising the DG and storage utilisation efficiency in the presence of RTP. The performance of the proposed solution is assessed through a comparative study by carrying out simulation experiments for a set of operational scenarios. The numerical result demonstrates that the proposed energy dispatch solution can well meet the demand requirement with significantly reduced electricity purchase cost. With the recognition that the prediction of RTP and DG output can often be inaccurate, the robustness of the solution is further verified under prediction errors. © The Institution of Engineering and Technology 2017.
Hong Y.,Zhejiang University |
He B.,Power China Huadong Engineering Ltd Corporation |
Wang L.Z.,Zhejiang University |
Wang Z.,China Communications Construction Company Ltd. |
And 2 more authors.
Canadian Geotechnical Journal | Year: 2017
Previous studies on laterally loaded piles in clay have mainly focused on flexible and rigid piles. Little attention has been paid to semi-rigid piles (whose pile-soil stiffness lies somewhere between those of rigid and flexible piles), which may behave as either flexible piles or rigid piles, depending on the change in soil stiffness during cycling. This study aims to understand the cyclic lateral response of a repeatedly loaded semi-rigid pile in soft clay and the failure mechanisms of the soil around the pile, through a series of centrifuge model tests and three-dimensional finite element analyses using an advanced hypoplastic clay model. Numerical parametric studies were also performed to investigate the evolution of soil flow mechanisms with increasing pile rigidity. It is revealed that the semi-rigid pile behaved as if it were a flexible pile (i.e., flexural deformation dominated) during the first few cycles, but tended to behave like a rigid pile (i.e., rotational movement prevailed) during subsequent cycles, which progressively softened the surrounding soil. As a result, the mechanisms of soil flow around the semi-rigid pile exhibited an intermediate behaviour combining the mechanisms of both flexible and rigid piles. Three distinctive mechanisms were identified: a wedge-type mechanism near the surface, a full-flow mechanism (within the transverse sections) near the middle of the pile, and a rotational soil flow mechanism (in the vertical symmetrical plane of the pile) near the lower half of the pile. By ignoring the rotational soil flow mechanism, which has a much lower resistance than the full-flow mechanism, the American Petroleum Institute code (published in 2007) underestimated the cyclic bending moment and the lateral pile displacement by 10% and 69%, respectively. Application of jet grouting around the semi-rigid pile at shallow depth significantly altered the soil flow mechanism (i.e., it was a solely wedge-type mechanism around the grouted zone). © 2017, Canadian Science Publishing. All rights reserved.
Zhao S.,South China University of Technology |
Zhou X.,South China University of Technology |
Zhou X.,Powerchina Huadong Engineering Corporation Ltd
Granular Matter | Year: 2017
Particle shape has been regarded as a key factor affecting mechanical behaviors of granular assemblies. The present work proposes a shape descriptor, i.e., asphericity, to isolate the effect of aspect ratio and angularity. A series of numerical triaxial compression tests are conducted on mono-disperse assemblies with different asphericities using a superball-based discrete element model. The corresponding mechanical behaviors are investigated from both macroscopic and microscopic points of view. Effects of particle asphericity are examined as well. It demonstrates that particle asphericity is able to enhance the particle–particle inter-locking with higher locked-in forces, showing an increasing proportion of sliding contacts, thereby making a granular assembly stiffer and stronger. In addition, weak contacts have a dominant proportion in the overall contact networks, positively correlated with asphericity. However, asphericity has an insignificant effect on the mean coordination number at the critical state. Furthermore, an established analytical stress–force–fabric relationship is verified using the present data. Anisotropy within an assembly is quantified in terms of several measures, i.e., contact normals, normal and tangential branch vectors, and normal and tangential contact forces. It is found that anisotropy of granular fabric is strongly determined by anisotropy sources in strong contact networks, where a larger asphericity results in a more anisotropic granular fabric. © 2017, Springer-Verlag Berlin Heidelberg.
He Q.,Power China Huadong Engineering Corporation Ltd
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2016
Three kinds of data length and three kinds of tidal current energy resources assessment methods are compared and analyzed using the observation data of Daishan in Hangzhou bay. The calculation results showed that the method of calculated directly by taking average is most accurate, but need stricter data length and resolution requirements. Velocity grading distribution calculation method applicable to a wider range of data interval is not required strictly, and the data reflect the full length of the long tidal cycle trend can also be. The precision of spring and neap maximum velocity assessment method is lowest due to many approximations are used. Data length of one month is a basic requirement, more than one month is better, a tidal cycle(including spring medium and neap tide) data can also be used, but only spring and neap tidal maximum current speed data is generally not recommended. © 2016, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.
Mei T.,Zhejiang University |
Tang Y.,Power China Huadong Engineering Corporation Ltd |
Gan D.,Zhejiang University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2016
Equity is one of the foremost considerations in free allocation of power system carbon emission, while the impact of historical deficits is one of the key essentials in fair distribution. Based on Shapley values, a historical deficit sharing model capable of solving the allocation problem of historical deficits in the emission reduction year is established and axiomatized. In accordance with the principle that whoever causes the issue should be responsible for it, a historical emission deficit sharing model among the units is developed, which is capable of solving the reduction of unit's claims caused by historical deficits. On this basis, with the consistency constraint of the allocation method taken into account, an allocation model for initial emission allowances considering the historical emission deficit is established. Furthermore, the participants' gaming behaviors under the aggregation mechanism are studied, which proved the existence of game equilibrium. In the meantime, the properties of the historical emission deficits sharing model such as anonymity, efficiency and independence of irrelevant share are proved, and the fair ranking is discussed. In the end, it is proved by a case study that as the proposed method meets the basic requirements for fair allocation, it can be easily accepted by the participants. © 2016 Automation of Electric Power Systems Press.
POWERCHINA HUADONG ENGINEERING CORPORATION Ltd | Date: 2015-03-07
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.