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You H.,China Earthquake Disaster Prevention Center | Zhao F.,China Earthquake Disaster Prevention Center
Dianwang Jishu/Power System Technology | Year: 2013

"Seismic qualification for high-voltage switchgear and controlgear" (GB/T13540-2009) is a newly revised recommended Chinese national standard that promotes the popularization and application of serial IEC standards in China. Based on the actual situation in China, the defects existing in this revised standard, such as seismic fortification goal and level and required response spectrum (RRS) and so on, are pointed out. Through the analysis on probabilistic seismic hazard at typical region, some modification proposals on the selection of seismic performance levels of electrical equipments are put forward. The applicability of RSS, the maximum dynamic amplification coefficient, the characteristic period and the transfer relationship among response spectra with different damping ratios are analyzed. It is wished that these proposals could be available for reference to the revision of relevant codes and standards.

Wang D.,China Earthquake Disaster Prevention Center
Applied Mechanics and Materials | Year: 2013

Earthquake damage prediction is a fundamental topic for working out the urban earthquake disaster prevention planning, improving earthquake emergency plans and preparedness, establishing seismic fortification criterion, and achieving the goal of earthquake preparedness and disaster reduction. It's significant to carry out urban seismic damage prediction. To display and apply the results of damage prediction more scientifically, intuitively, integrally, objectively and fully, the technical methods and ideas of using virtual simulation technology are proposed and studied, and the system requirements, functional design and structural framework are also described in this paper. These studies will provide effective technical support for the damage prediction to serve the urban disaster reduction, improvement of people's awareness of disaster prevention and refuge and so on, and have good application prospects. © (2013) Trans Tech Publications, Switzerland.

Wang D.,China Earthquake Disaster Prevention Center
Journal of Natural Disasters | Year: 2012

Earthquake disaster has the characteristics of abruptness, hard to predict, wide range and great losses etc. After the occurrence of earthquake, a series of relief efforts and measures, including urgent rescue, emergency wrecking, victims settlement and restoration and reconstruction, etc., need to be carried out and developed immediately, the precondition of which are fast, systematic, and objective investigations and evaluations to the earthquake disasters. Hence, a professional earthquake disaster estimation group with efficiency and capability is necessary, and construction of a network-based earthquake disaster estimation and investigation training system platform is urgently in need. The network domain name of China's earthquake disaster losses investigation and training system (CEDLIATS) is http://www. cedliats. cn, whose functions are as follows; (1) Registration, classification management and online exchanges for workers of earthquake disaster losses investigation; (2) Providing remote training service, including knowledge propaganda, test paper answers, situation deduction, synthetic simulation maneuvers, and many kinds of training modes that can automaticly evaluate training effectiveness; (3) Promoting the data of disaster loss investigation and evaluation report, backup, and share timely; (4) Establishing the linkage system of front and back land during earthquakes, realizing the task decomposition and seamless splice, and effectively improving the whole speed and quality of disaster evaluation. In a word, the efficiency and level of national earthquake disaster estimation and investigation is expected to overall promoted after the system's running.

Zhang Y.-S.,China Earthquake Disaster Prevention Center
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

For the two-dimensional scattering problem of plane SH waves in alluvial valley with a circular-arc section, some researchers proposed a type of closed-form analytical solution, which reduced the scattering problem into the solution of an infinite-dimensional algebraic equation system. The high incident frequency will cause the system coefficient matrix to be ill-conditioned, which limits the usable frequency band of the analytical solution. Here, the method of this solution is followed, however, in the solving procedure, the solution of linear equation system is avoided by selecting coordinate system, with the undetermined coefficients of scattering wave functions possessing definite analytical expressions. As a result, the analytical solution to this scattering problem is presented in a very broad frequency band, and the influence of the properties of the incident wave as well as the valley on the ground motion is discussed.

Wang D.,China Earthquake Disaster Prevention Center
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2013

It's of vital importance to adhere to the principle of 'bi-safety' for both rescuer and trapped people in the earthquake emergency relief field. The capability of rescue teams can be judged by the execution level of this principle. The ruins formed from the damaged buildings are mostly in a temporary stable state, which may result in various unstable conditions during rescue. Therefore, scientific evaluation and precautionary measures should be taken. Currently, there are only a few experts who grasp the safety assessment theory of earthquake ruins structure and have the rescue practice experience, while one or a few rescue team have been established in each province, which shows that the needs of the experts in the field to the actual number of experts is out of proportion. Therefore, this paper puts forward an idea of China earthquake rescue ruins safety assessment management system (CERRSAMS), which can serve all kinds of national rescue teams. The objectives are as follows: 1. Strengthen the management of earthquake relief industry; 2. Integrate and share the existing resources of earthquake ruin safety evaluation; 3. Establish the expert system of earthquake ruin safety evaluation for technology support to rescue team; 4. Enhance the training and examination of earthquake relief industry; 5. Provide industry communication interactive platform; 6. Set up remote platform that communicating with experts. What's more, this paper also presents the demand of CERRSAMS, designing the system framework, function constitution, layout scheme and security mechanism, introducing the system technology realization and analyzing the characteristics of the system.

Zhang Y.,China Earthquake Disaster Prevention Center | Zhao F.,China Earthquake Disaster Prevention Center | Yang C.,China Earthquake Disaster Prevention Center
Bulletin of the Seismological Society of America | Year: 2012

In this paper, a synthesizing method based on the Hilbert transform is proposed to generate artificial earthquake ground-motion samples, the nonstationary features of which are similar to those of given natural seismic recordings. With this aim in mind, the given natural seismogram, assumed to be a sample of some underlying random process, is first processed by the Hilbert transform to obtain its instantaneous amplitude and instantaneous phase functions. The instantaneous amplitude function is treated as an invariant variable for which the value will be preserved into the synthetic samples, whereas the instantaneous phase function is treated stochastically to address the randomness of the underlying ground-motion process. By establishing the stochastic model for the instantaneous phase function, the underlying ground-motion random process can be determined, and a series of its samples can be generated numerically. Synthetic examples demonstrate that the ground-motion samples generated by the proposed method can maintain the general time-variant features of original natural ground motions, and the method has application potential either in the engineering practice or in earthquake engineering research.

Zhang Y.,China Earthquake Disaster Prevention Center | Zhao F.,China Earthquake Disaster Prevention Center
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2014

An improved wavelet-based spectral matching method is proposed to modify given ground motion to make its response spectrum match the target spectrum more precisely. An incremental acceleration wavelet function is constructed with following two properties: (1) at some controlling period of response spectrum, after being time-shifted and linear-scaled, the wavelet can be superimposed onto the initial ground motion to generate a new one whose spectrum is equal to the target value at this controlling period; (2) the incremental velocity and displacement obtained by integrating the wavelet do not exhibit baseline drift, thus there is no additional baseline drift when superimposing it onto the initial ground motion. Based on the wavelet, an iterative modification method is proposed to eliminate the coupling effects among different controlling periods of response spectrum to realize the matching of whole target spectrum. Numerical results show that the ground motion synthesized by the method can not only match the target spectrum with relatively high precision, but also retain the basic features of original natural ground motion, so the rationality and reliability of analysis of structural dynamic responses can be ensured. In addition, the proposed method can realize high matching precision with limited iterations.

Zhang Y.-S.,China Earthquake Disaster Prevention Center
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2010

By the method of Fourier-Bessel series expansion of wave functions, the paper presents an analytical solution to the two-dimension stationary dynamic response of alluvial valley containing arbitrary number of circular-arc-shaped layers, excited by incident Rayleigh waves. And not only the convergence of the proposed series-form analytical solution with the truncation number of series terms is analyzed, but also the influence of the number of the terms of the finite Fourier series which determine the free-field displacement and stress of the incident Rayleigh wave, as well as that of the radius of the big arc which simulates approximately the flat half-space surface, on the solution is discussed. The results show that the proposed analytical solution can converge in a very broad frequency band. At last, by the proposed solution, the layering effects of the deposit in the valley, such as the number of alluvial layers, the existence of soft interlayer and its thickness, etc., on the ground motion are investigated in a broad frequency band.

You H.-B.,China Earthquake Disaster Prevention Center
Applied Mechanics and Materials | Year: 2011

A hybrid simulation method is used to generate two group artificial ground motions that are compatible with the same acceleration response spectrum, same peak displacement and different peak ground velocity (PGV). The influences of PGV on the internal forces of subway station are studied. For the time histories with the same response spectrum and same peak displacement, the larger PGV of input motions may lead to the great plastic deformation of the soil, and then cause the larger internal forces for the most elements of subway station. The influence of PGV should be considered reasonably in determination of design ground motion parameters for underground structures. © (2011) Trans Tech Publications.

Zhang Y.,China Earthquake Disaster Prevention Center | Zhao F.,China Earthquake Disaster Prevention Center
Nuclear Engineering and Design | Year: 2010

With respect to the design ground motion of nuclear power plant (NPP), the Regular Guide 1.60 of the US not only defined the standard multi-damping response spectra, i.e. the RG1.60 spectra, but also definitely prescribed the peak ground displacement (PGD) value corresponding to the standard spectra. However, in the engineering practice of generating multi-damping-spectra- compatible artificial ground motion for the seismic design of NPP, the PGD value had been neglected. Addressing this issue, this paper proposed a synthesizing method which generates the artificial ground motion compatible with not only the target multi-damping response spectra but also the specified PGD value. Firstly, by the transfer formula between the power spectrum and the response spectrum, an initial uniformly modulated acceleration time history is synthesized by multiplying the stationary Gaussian process with the prescribed intensity envelope to simulate the amplitude-non-stationarity of earthquake ground motion. And then by superimposing a series of narrow-band time histories in the time domain, the initial time history is modified in the iterative manner to match the target PGD as well as the target multi-damping spectra with the pre-specified matching precisions. Numerical examples are provided to demonstrate the matching precisions of the proposed method to the target values. © 2010 Elsevier B.V. All rights reserved.

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