Wave Runup-Rundown Ampu''''tude on Slopes     

Xue Hongchao  Guo Da  Pan Shaohua Zhong Hushui Professors  Hohai University  Nanjing Associate Professors  Hohai University  Nanjing 《中国海洋工程》1991,(1)

This paper gives an overall discussion about water level change on slopes under wave action, including wave runup, wave rundown and wave up-down amplitude, and a suggested formula for their calculation.  相似文献   

A dynamic study of explosive cyclogeneses developments over the ocean     

张永刚  孙成志  吕美仲  欧阳子济 《海洋预报》2001,18(Z1)

1 IwrRODUcrIONIt is necessary to understand disastrous weather systems as the activities of exploitingand uti1izing marine resources, especialIy for the needs of navigation and oil-gas prospecting.Typhoon is the most frequent and dangerous disastrous weather system in summer-autumnseason in the Nolthwest Pacific Ocean. The explosive cyclogenesis developing quickly overocean is the most terrible weather system in winteL The explosive cycnogenesis grows fastwith high intensity of violent wi…  相似文献   

The SWAN model used to study wave evolution in a flume   总被引：1，自引：0，他引：1  

Deborah J. Wood  Research Assistant  Markus Muttray  Research Engineer  Professor Hocine Oumeraci   《Ocean Engineering》2001,28(7)

The SWAN numerical model is used to model the evolution of JONSWAP wave spectra and hence the significant wave height of waves in a tank. Comparison with experiment has shown that modelling triad interactions in the numerical model leads to too low predictions of spectra and significant wave height and should therefore be excluded. The modelling of the breaking constant was also investigated, by looking at the use of a constant breaking constant, Nelson formula, and Goda formula (added into SWAN for this study). Using a constant value of 0.78 within SWAN gave the best comparison between theory and experiment.  相似文献   

Dynamic Analysis for Structures Isolated with Dampers     

Gu Peiying  Gao Ming M. Sc  Engineer  Material  Structure Department  Nanjing Hydraulic Research Institute  Nanjing Professor  Material  Structure Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1996,(3)

- In this paper, mathematical models and dynamic analyses for both SDOF and MDOF structures isolated with dampers are established and performed, and a comprehensive computation method is provided. The shock absorbing effect is illustrated through an example of a two DOF damper-isolated system excited by sinusoidal waves and actual ground acceleration input recorded in earthquakes. It is shown that most of the responses of the structure with dampers reduce greatly near the resonant zone, but acceleration is enlarged in the lower or higher frequency zone; among various parameters, the influence of frictional coefficient n is the most significant, that of damping ratio of the dampers , is the second, and that of stiffness coefficient of the dampers k, is the slightest.  相似文献   

Numerical Study of Oil Pollution on Sea Waters     

Geng Zhaoquan  Ni Yongqiang  Zhou Anguo Senior Engineer  Zhejiang Provincial Institute of Estuarine  Coastal Engineering Research  Hangzhou Engineer  Zhejiang Provincial Institute of Estuarine  Coastal Engineering Research  Hangzhou Engineer  Zhejiang Institute of Environmental Protection Science  Hangzhou 《中国海洋工程》1992,(1)

This paper adopted an upstream FEM of 2-D unsteady flow to calculate the tidal flow in Zhoushan sea area. Based on the verification of the tidal current and environmental situation, the effects of the oily waste discharged from the oil berths on water quality have been calculated with a similar method. The isodilutions of oil pollutant are drawn from different sewage discharges. The moving loci of the slick centrepoint of oil spill have been calculated. The spreading area of the oil spill has also been forecasted. The results indicate that the set of models can predict the transport of oil spill in the sea area with reasonable accuracy.  相似文献   

Qualification Test for the Reliability of Diver Gas Recovery System     

Mao Fangguan  Lu Shunchang  Luo Ruiren Senior Engineer  The Naval Medical Research Institute  Shanghai . Senior Engineer  The Navigation Guarantee 《中国海洋工程》1997,(3)

A qualification test for the reliability of a newly-developed Diver Gas Recovery System(DGRS)was carried out in the Naval Medical Research Institute of the People's Liberation Army,Chinafrom March 29 to April 2,1995.A sequential test plan of high discrimination ratio for the mean time be-tween failures(MTBF)was adopted.The test procedures simulated those of a 300 msw dive.A hyperbaricbreathing machine was used for the simulation of diver's respiratory functions.Parameters,such as divingdepth,respiratory minute volume(RMV),CO_2 production,gas flow rate,partial pressure of carbondioxide,and ambient temperature and himidity were all displayed and recorded with a microcomputer sys-tem.The results indicated that no failure occurred during the 91.5 h operation.According to the accept-ance and rejection criteria specified in the statistical test plan,a no-failure score in the 88 h operation is ac-ceptable.Therefore,the DGRS has been demonstrated to meet the requirements of MTBF specified in thecontract.  相似文献   

Test Study on Erosion and Siltation Patterns of Sandy Bottom Before Mound Breakwater Under the Effect of Waves     

Zhang Furan  Wang Huaren Zhao Jun Assistant Researcher  Tianjin Research Institute of Water Transport Engineering    Tianjin Assistant Engineer  Tianjin Research Institute of Water Transport Engineering    Tianjin 《中国海洋工程》1992,(4)

In this paper, the effect of waves on erosion of the sandy bottom before mound breakwaters is studied. The sandy bottom basically presents two erosion patterns, between which there is a transitional state, under the action of partially standing waves. The two erosion patterns can be determined by dimensionless parameter Us, defined in this paper. The erosion locations, depths and lengths can be estimated by a series of equations presented in the text. Irregular waves are employed in the test besides regular waves, and the effect of the irregular waves can be estimated by the element of equivalent waves, such as T1/3, H1/3.  相似文献   

Application of Explosion Method to Soft Foundation Treatment of Great-West Dyke,Lianyungang Port     

Liu Huairen Engineer  Fifth Engineering Company  Third Navigational Engineering Bureau  The Ministry of Communications  Lianyungang 《中国海洋工程》1995,(2)

Explosion for the treatment of underwater soft foundation is a technique newly developed in China. This paper describes the application of the method of explosion to underwater soft foundation treatment of the Great-West Dyke, Lianyungang Port, including the technical characteristics and the effect, selection of explosion parameters, workmanship of construction, requirements of quality and inspection, and the like.  相似文献   

Study on First-Yield Collapse of Submarine Pipelines     

Zhang Wenge Li Dexiang Associate Professor  Dalian Railroad Institute  Dalian . Engineer  Dalian New Shipyard  Dalian 《中国海洋工程》1997,(4)

-The first-yield collapse of submarine pipelines with an initial out-of-roundness imperfection un-der combined bending and external pressure load is formulated by means of the Von.Mises yield criterion.The formula reduces to Timoshenko and Gere's expression in the case of external pressure load alone.Theinfluence curves of various parameters on the yield strength are presented,the collapse of submarinepipelines in a deep water region is numerically predicted,and the effect of pre-yield nonlinear bending onthe yield strength is also examined.  相似文献   

Pore Water Pressure Buildup Under Cyclic Rotation of Principal Stress and Stability Evaluation of Seabed Deposit     

Shen Ruifu  Wang Hongjin  Zhou Jinxing  Zhou Keji Former graduate student of Tsinghua University  now works in Nanjing Hydraulic Research Institute  Nanjing Professor  Tsinghua University  Beijing Senior Engineer  Tsinghua University  Beijing 《中国海洋工程》1994,(4)

- The cyclic rotation of principal stress direction with a constant amplitude is the characteristics of cyclic stress in seabed deposit induced by travelling waves. Presented in the paper are the results obtained from tests simulating the cyclic stress characteristics, with emphasis laid on the buildup of pore water pressure in soil samples. Regression analysis of test data shows that the pore water pressure can be expressed as the function of the number of cycles of cyclic loading, or as the function of generalized shear strain. Using the results thus obtained, the possibility of failure of seabed deposit under cyclic loading induced by travelling waves can be evaluated. The comparison with the results of conventional cyclic torsional shear tests shows that neglect of the effect of the cyclic rotation of the principal stress direction will result in considerable over-estimation of the stability of seabed deposit.  相似文献