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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

Fu J.,Central South University | Yang J.,Central South University | Zhu S.,Power China Huadong Engineering Corporation Ltd | Shi Y.,East China Jiaotong University
Journal of Performance of Constructed Facilities | Year: 2017

Protective interventions are often needed to protect sensitive buildings from ground deformation induced by tunneling. This paper evaluates the effectiveness of underground jet-grouted partition wall in mitigating the effects of shield-tunnel construction on existing piled structures by means of numerical analysis and field monitoring. It is shown that the tunneling-induced displacements field can be modified by the underground partition wall in different ways depending on the combination of influential factors, such as wall stiffness, partition range angle, and insert depth below the tunnel invert. The results also indicate that the presence of the partition wall can relieve the existing piles from suffering from differential displacement, thereby improving the mechanical performance of pile-pier interaction. The reasonable agreement found between the observed field measurements and the numerical results demonstrates that underground jet-grouted partition wall can serve as an effective recourse of ground movement control given the need of tunneling nearby piled structures. © 2016 American Society of Civil Engineers.

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.

Cui Z.,CAS Wuhan Institute of Rock and Soil Mechanics | Cui Z.,Power China 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

Seismic wave propagation through joints that are embedded in a rock mass is a critical issue for aseismic issues of underground rock engineering. Few studies have investigated nonlinear joints with a continuously yielding model. In this paper, a time-domain recursive method (TDRM) for an S wave across a nonlinear Mohr–Coulomb (MC) slip model is extended to a continuously yielding (CY) model. Verification of the TDRM-based results is conducted by comparison with the simulated results via a built-in model of 3DEC code. Using parametric studies, the effect of normal stress level, amplitude of incident wave, initial joint shear stiffness, and joint spacing is discussed and interpreted for engineering applications because a proper in situ stress level (overburden depth) and acceptable quality of surrounding rock mass are beneficial for seismic stability issues of underground rock excavation. Comparison between the results from the MC model and the CY model is presented both for an idealized impulse excitation and a real ground motion record. Compared with the MC model, complex joint behaviors, such as tangential stiffness degradation, normal stress dependence, and the hysteresis effect, that occurred in the wave propagation can be described with the CY model. The MC model seems to underestimate the joint shear displacement in a high normal stress state and in a real ground motion excitation case. © 2016 Springer-Verlag Wien

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

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.

Fu J.,Central South University | Yang J.,Central South University | Zhu S.,Power China Huadong Engineering Corporation Ltd
Geotechnical Special Publication | Year: 2016

Technical measures, such as underground partition wall, could sever as recourse to mitigate the ground movements induced by excavation. In this paper field monitoring and numerical analysis were used to examine the performance of underground jet-grouted partition wall in mitigating the effects of shield tunnel construction on existing pier of Xin-Zhong Road viaduct in the project of Changsha Subway Line 1 in China. The performance of the jet-grouted partition wall was calibrated by the reasonable agreement found between the observed field measurements and the numerical results. Underground jet-grouted-column partition wall was testified to serve as an effective measure in ground movement control given the need of tunnelling nearby piled structures. © ASCE.

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.


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.

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