The Development And Application Of Simulation Of Earthquake Accelerations

In order to guarantee that the structure has the sufficient ability to resist earthquake disaster in life-span, we must grasp the dynamic response of the structure which is excited by the certain earthquake load. Within the last few decades, wet have a more profound understanding to the seismic motion by the unremitting research to earthquake. Yet it certainly cannot really represent all seismic motion where the construction will be built, because of the different site condition; on the contrary, we cannot get a group of earthquake records where the large-span is located.Therefore, it is extremely essential to simulating the ground motion which has the certain characteristic parameter, conforms to the specific site condition and with the space correlation. In order for readers to simulate ground motions, Yang and Tian composes a book named "Simulation of Correlation Ground Motions for Engineering Design", which is a summary of the research results in this filed. For the reader's convenience and the demand of numeric computations, "Simulation of Earthquake Accelerations" software ("SEAS") has been developed with the mixed programming of Visual C++ 6.0 ("VC++") and Visual FORTRAN 6.5 ("VF"). The software is systematically introduced in this dissertation.With the beginning of the development and state-of-the-art of the ground motion's features and artificial generation, the thesis addresses the problems to work out in the simulating ground motion study. Yang et al finished the "Simulation of Correlation Ground Motions for Engineering Design" and developed the supporting software of it. The Fast Fourier Transform algorithm has been used in core program of this software. We can get a certain history's spectrums by applying Fourier Transform. On the contrary, when the Fourier Spectrum is known, we can get the artificial seismic wave (or artificial Earthquake Ground Motion Field) by applying Inverted Fourier Transform. In the chapter 2 of the thesis, the theory of Fourier Transform, spectral analysis and generating Earthquake Ground Motion wave (Field) is briefly introduced.The software has the friendly and efficient interactive interface, fast and accurate calculations, clear and succinct graph display, and powerful document management functions. With a modular design idea, there is man-machine interaction module, analysis module, and graphics processing module. And it has a clear structure of software systems.The installation, running and operation of this software is illustrated in this article, with software's interface shows. Since the software is a visual program developed by Visual C++, the installation and operation is similar to common software, being easily learned. Operation of the program is through menus and dialog boxes, so it is easy to grasp.The program is for the application of spectral analysis, generating seismic wave and ground motion field. Analysis of the spectrum is to get waves' various spectra by Fourier Transform. Generation of seismic waves is based on the use of envelope function or phase difference spectrum. And it is able to make the response spectra of seismic wave matching the design spectrum in "Seismic Design Code of Chinese Building". In addition, it is available to generate near-fault ground motions. With the space correlation of earthquake ground motion, we can use the spatial coherency function and power spectrum model to generate the correlated ground motions, which is a group of seismic waves. In the dissertation, the application of the calculation process and the selection of the various model parameters is been presented. Also, several typical examples to the different applications or methods are given.