A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within ...A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within Bahia de Todos Santos (BTS), west coast of Mexico. Experiments with forcing frequencies f = 50?1 min?1, f = 30?1 min?1, f = 25?1 min?1 and f = 16.66?1 min?1 showed the expected increase of energy at the corresponding forcing frequency band and also the appearance of secondary peaks of energy at frequency bands f = 8.33?1 min?1 and f = 4.16?1 min?1 which were identified as modes f<sub>1 </sub>and f<sub>2</sub>;being the band at f = 16.66?1 min?1 the zeroth f<sub>0</sub> mode. Maximum peak of spectral energy from the numerical experiments was found at frequency band f<sub>0</sub> = 16.66?1 min?1 which agreed with the estimated maximum value of the amplification factor and with the T<sub>0</sub> mode of oscillation of the port. Distribution of amplitudes inside PE for modes f<sub>0</sub>, f<sub>1</sub> and f<sub>2</sub> were also presented. Mode f<sub>0</sub> represents a quarter-wave oscillation with amplitudes of the same sign;mode f<sub>1</sub> has two nodal lines and mode f<sub>2</sub> presents and additional one. Corresponding harbor currents were also calculated, they were in the range 20 - 160 cm?s?1. Finally, in order to elucidate the source of the external signals found in the spectral analysis of this study, the natural oscillation modes of the BTS were estimated. Although more studies are needed, BTS oscillation mode T<sub>2</sub> = 16.82 min, was identified as the external forcing that excites larger oscillations within the port.展开更多
In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and proble...In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and problems encountered. China has attached much importance to the rehabilitation and modernization of war damaged existing ports and the construction of new ports, as well as the maintenance and strengthening of coast protection works.展开更多
This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in...This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in USA for transportation professionals world-wide, especially those in Asian and Pacific regions. Seismic vulnerability of a transportation infrastructure is determined by the risk associated with the seismic ground motion and specified performance criteria. Determining an acceptable seismic risk is a very complex task that must consider both social and economic aspects. Obviously, the amount of risk that a railway bridge can accept may be different from that of a highway bridge. The economic tolerance in one country may be different from that in another country for the same type of infrastructure. In this paper, seismic performance levels and design criteria of ground motion for highway bridges, railway bridges and ports＇ container wharves in USA are reviewed, and design examples are presented to demonstrate how to develop the code-based and site-specific design acceleration response spectra and time histories.展开更多
This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the freq...This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the frequency spectrum of wind-waves.展开更多
文摘A series of numerical experiments from a barotropic configuration of the General Curvilinear Ocean Model (GCOM) was conducted to analyze the response to infragravity (IG) waves of the Port of Ensenada, located within Bahia de Todos Santos (BTS), west coast of Mexico. Experiments with forcing frequencies f = 50?1 min?1, f = 30?1 min?1, f = 25?1 min?1 and f = 16.66?1 min?1 showed the expected increase of energy at the corresponding forcing frequency band and also the appearance of secondary peaks of energy at frequency bands f = 8.33?1 min?1 and f = 4.16?1 min?1 which were identified as modes f<sub>1 </sub>and f<sub>2</sub>;being the band at f = 16.66?1 min?1 the zeroth f<sub>0</sub> mode. Maximum peak of spectral energy from the numerical experiments was found at frequency band f<sub>0</sub> = 16.66?1 min?1 which agreed with the estimated maximum value of the amplification factor and with the T<sub>0</sub> mode of oscillation of the port. Distribution of amplitudes inside PE for modes f<sub>0</sub>, f<sub>1</sub> and f<sub>2</sub> were also presented. Mode f<sub>0</sub> represents a quarter-wave oscillation with amplitudes of the same sign;mode f<sub>1</sub> has two nodal lines and mode f<sub>2</sub> presents and additional one. Corresponding harbor currents were also calculated, they were in the range 20 - 160 cm?s?1. Finally, in order to elucidate the source of the external signals found in the spectral analysis of this study, the natural oscillation modes of the BTS were estimated. Although more studies are needed, BTS oscillation mode T<sub>2</sub> = 16.82 min, was identified as the external forcing that excites larger oscillations within the port.
基金This article is reprinted by permission from The Proceedings of Coastal & Port Engineering in Developing Countries(ISBN 7-5027-0052-8/P.17),1987,Vol.Ⅰ.
文摘In this paper, a brief account of the characteristic features of the coast of China is given, followed by the present status and future prospects of coastal and port engineering in China, experiences gained and problems encountered. China has attached much importance to the rehabilitation and modernization of war damaged existing ports and the construction of new ports, as well as the maintenance and strengthening of coast protection works.
文摘This paper provides an overview of current seismic ground motion criteria for transportation infrastructures in USA. This is to facilitate an understanding of current seismic performance levels and design practices in USA for transportation professionals world-wide, especially those in Asian and Pacific regions. Seismic vulnerability of a transportation infrastructure is determined by the risk associated with the seismic ground motion and specified performance criteria. Determining an acceptable seismic risk is a very complex task that must consider both social and economic aspects. Obviously, the amount of risk that a railway bridge can accept may be different from that of a highway bridge. The economic tolerance in one country may be different from that in another country for the same type of infrastructure. In this paper, seismic performance levels and design criteria of ground motion for highway bridges, railway bridges and ports＇ container wharves in USA are reviewed, and design examples are presented to demonstrate how to develop the code-based and site-specific design acceleration response spectra and time histories.
文摘This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the frequency spectrum of wind-waves.
