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Numerical wave simulation under hypothetical typhoon conditions has a pivotal role in the risk assessment of cross-sea bridges and tunnels. The wind-field generation and the adverse track selection have a large influence on the wave simulation results. This study verified the rationality of wave simulation under a single hypothetical typhoon wind field and analyzed the effects of different typhoon tracks on the waves in different directions of the project area. A numerical wind-wave model in the Pearl River Estuary was constructed according to intensities based on a 300-yr return period and tested via Monte Carlo simulation, which was applied to 104 typhoon tracks selected by the radius method. The results show that the adverse tracks that significantly impact the wave field at the West Artificial Island are within 100 km of the Pearl River Estuary. Seven adverse typhoon tracks reflecting different characteristics were obtained, which provided a basis for further study of the typhoon wave process in the Pearl River Estuary under extreme weather conditions. This study provides methodological support for the wave parameter analysis of large-scale engineering at coasts and estuaries that are susceptible to typhoons. [ABSTRACT FROM AUTHOR]

The artificial island of Hong Kong-Zliuliai-Macao Bridge is located in Lingding Sea area, llie overtopping could endanger the operation of the artificial island and tunnel in storm period. The overtopping rate is important factors in the design of the artificial island. 2-D physical model tests are carried to study the influence of the different structure factors to wave overtopping, such as armour block type, herm width and elevation, armour width in front of the wall. The test results show that the armour width has significant influence on the overtopping, and the test value is obviously smaller than the calculating value of van der Meer formula when the overtopping rale is relative small. After that, a calculation formula of the average overtopping discharge rate are presented for the artificial island of Hong Kong-Zliuliai- Macao Bridge, in which the armour width factor Kv is involved. The calculating results show good a-greement with the experimental data, and can he used in the optimization design and overtopping warning in operation of the artificial island. [ABSTRACT FROM AUTHOR]

During the design process of sea-crossing bridges and tunnels, it is necessary to estimate the design flow velocities at different recurrence periods for the project location. However, the lack of on-site long-term flow observation data makes such estimations very difficult. Based on typical storm surge processes with different return periods, a numerical method was proposed for estimating design flow velocities for estuaries and coastal areas, for which the coupling of flood runoff and storm tidal currents was considered for the estuarine areas. According to the measured tide level data from the Macao tide station from 1925 to 2003, the characteristics of historical storm surge processes in the Pearl River estuary were analyzed, and typical storm surge processes of different return periods were obtained based on the results of the analysis of annual extreme frequencies of tidal levels and tidal ranges. Then, a horizontal two-dimensional hvdrodvnamic numerical model was established to simulate the flow field in the Pearl River estuarv under the combined conditions of storm surges with different return periods and general upstream flooding. With such a model, design flow velocities at control points along the Hong Kong-Zhuhai- Macao Bridge were determined. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)