Calculation of Wave Pressure and Pressure Spectrum for Perforate-Pipe Breakwater   总被引：1，自引：0，他引：1  

Li Chunzhu  Shi Hongda  Yu Dingyong Wang Aiqun Professor  Engineering College  Ocean University of Qingdao  Qingdao Lecturer  Engineering College  Ocean University of Qingdao  Qingdao Senior Engineer  Engineering College  Ocean University of Qingdao  Qingdao 《中国海洋工程》1997,(1)

Standing waves are formed due to the reflection when waves meet vertical wall,thereforestrong structures are needed to keep the wall stability under the serious wave attack.For the improvementof the working condition and increase of the stability of the wall,the lower reflecting breakwaters have at-tracted close attention Reports mostly from Japanese researchers are often concerned with the wall ofcaisson equipped with open windows.In this paper a kind of hollow-pipe perforated breakwater is exam-ined which waves may partially perforate into the harbour basin.The wave in front of the wall can onlyform partial standing wave and wave force is reduced obviously.And the theoretical calculation of waveforce and analysis of wave force spectrum are all derived.Comparison between the results from theoreticalcalculation and hydraulic modeling shows reasonable agreement.  相似文献   

Determination of Partial Factors of Breast Wall on Top of Sloping Breakwater     

Lu Jianghua Xie Shileng Engineer  Planning  Design Institute for Water Transportation  Ministry of Communications  Beijing Professor  Senior Engineer  First Design Institute of Navigation Engineering  Ministry of Communications  Tianjin 《中国海洋工程》1996,(4)

- By applying the theory of structural reliability, reliability analyses for the stability of a breast wall on the top of a sloping breakwater are carried out. Based on the analyses, the method for determining partial action / load factors and partial resistance factors of breast walls is expounded, and the design expressions with partial factors are given. The values of partial action / load factors and partial resistance factors are recommended preliminarily according to the computation for breast walls with typical cross-sections.  相似文献   

刚臂式单点系泊系统在波浪作用下的链力分析     

海工科研组 《海洋学报》1980,2(1):136-147

第一个刚臂式单点系泊储油装置(SBS)于1974年在突尼斯建成,以后在各地又建成了很多个这类装置,据报导其使用效果是令人满意的[1,2].为了发展我国海洋石油勘探、开发的科学技术,在海洋石油研究所的协助下,我们对这种系泊系统进行了波浪模型试验研究,本文在试验成果的基础上,主要研究单点浮筒多链系统的静力特性和波浪要素、水深等对链力的影响,还研究了减小中链力的措施.  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   

Viscoplastic Torsional Buckling of Cylindrical Shell     

Wang Deyu Chen Tieyun Associate Professor  Dept. of Naval Architecture  Ocean Engineering  Shanghai Jiaotong University  Shanghai Professor  Dept. of Naval Architecture  Ocean Engineering  Shanghai Jiaotong University  Shanghai 《中国海洋工程》1995,(1)

- The Bodner-Partom constitutive equation is used to study the viscoplastic torsional bucklingof perfect cylindrical shell. By treating the viscoplastic shell as an orthotropic shell at each moment and neglecting the inertia term, the critical torque is determined from a set of homogeneous linear equations. The strain rate sensitivity is mainly discussed in the present paper.  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   

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   

Semi-Active Control of Wave-Induced Vibration for Offshore Platforms by Use of MR Damper   总被引：2，自引：0，他引：2  

Li  Huajun 《中国海洋工程》2002,16(1):33-40

The objective of the present research is to examine the effectiveness of the lateral vibration control of wave-excited re-sponse of offshore platforms with magnelo-rheological (MR) damper, In this study, the offshore platform is simplified to be a single-degree-of-freedom (SDOF) system by extracting the first vibration mode of the struclure. The exlernal 'generalized' wave force is determined with a white noise via a designed filler. A semi-active control method based on optimal control the-ory is proposed considering that the yield stress of the MR damper can be varied continuously within a certain range. The dy-namics of SDOF structure coupled with the MR damper is investigated. Numerical simulation demonstrates that the MR damper with this control strategy can significantly reduce the maximum responses and the root-mean-square (RMS) values.  相似文献   

Experimental Study on Free Spanning Submarine Pipeline Under Dynamic Excitation   总被引：5，自引：0，他引：5  

LI  Xin 《中国海洋工程》2002,16(4):537-548

Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is con-structed in a seismically active region. The model experiment is performed on an underwater shaking tahle to simulate the response of submarine pipelines under dynamic input. In consideration of the effects of the terrestrial and submarine pipeline , water depth, support condition, distance from seabed, empty and full pipeline, and span on dynamic response, 120 groups of experiments are conducted. Affecting factors are analyzed and conclusions are drawn for reference. For the con-trol of dynamic response, the span of a submarine pipeline is by far more important than the other factors. Meanwhile, the rosponse difference between a submarine pipeline under sine excitation and that under random excitation exists in ex-periments.  相似文献   

Leak Detection in Offshore Pipelines of Conveying Fluid     

李俊花  崔莉 《中国海洋工程》2004,18(2):327-333

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