Monitoring fish movement patterns in a reservoir using horizontally scanning split-beam techniques     

Steig  Tracey W.; Johnston  Samuel V. 《ICES Journal of Marine Science》1996,53(2):435-441

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A Note on Soil Structure Resistance of Natural Marine Deposits   总被引：1，自引：1，他引：1  

洪振舜刘松玉  刘志方 《中国海洋工程》2004,18(2):321-326

It has been well documented that natural normally-consolidated marine soils are generally subjected to the effects of soil structure. The interpretation of the resistance of soil structure is an important issue in the theory study and engineering practice of ocean engineering and geotechnical engineering. It is traditionally considered that the resistance of soil structure gradually disappears with increasing stress level when the applied stress is beyond the consolidation yield stress. In this study, however, it is found that this traditional interpretation of the resistance of soil structure can not explain the strength behavior of natural marine deposits with a normally-consolidated stress history A new interpretation of the resistance of soil structure is proposed based on the strength behavior. In the preyield state, the undrained strength of natural marine deposits is composed of two components: one developed by the applied stress and the other developed by the resistance of soil structure. When the applied stress is beyond the consolidation yield stress, the strength behavior is independent of the resistance of soil structure.  相似文献   

Evaluation of the Risk of Marine Slope Instability: A Pseudo-3D Approach for Application to Large Areas     

Nabil Sultan  Pierre Cochonat  Jean Fran  ois Bourillet  Florence Cayocca 《Marine Georesources & Geotechnology》2001,19(2):107-133

This article presents a methodology developed to evaluate the instability of submarine slopes that extend over a large area. Special attention was paid to (1) the complex geometry (bathymetry) and the expanse of the slope, (2) the heterogeneity of the sediment, and (3) the distribution of the pore pressure. The safety factor was considered as a spatially varying quantity. The General Formulation (GLE, Fredlund and Krahn 1977), which fully satisfies equilibrium conditions, was used for evaluating the stability of the marine slope. The submarine slope failure, which occurred on 16 October 1979 during the construction of the new Nice airport, was studied in order to test the developed model. Geotechnical parameters were taken from experimental tests carried out by IFREMER on 19 cores extracted at different depths (from 27 m to 1300 m) (Cochonat, Bourillet, and Savoye, 1993; Mulder et al., 1994). Many scenarios were proposed in order to explain the cause of the Nice slope failure (Habib, 1994). In this article, two of those scenarios were tested. Simulation results are presented and discussed.  相似文献   

Fatigue Behavior of Plain Concrete Under Biaxial Compression: Experiments and Theoretical Model     

ZHU  Jin-song 《中国海洋工程》2003,17(4):617-630

The effects of different lateral confinement stress on the fatigue behavior of and cumulative damage to plain concrete are investigated experimentally. Eighty 100 mm x 100 mm x 100 mm specimens of ordinary strength concrete are tested under constant- or variable-amplitude fatigue loading and lateral confinement pressure in two orthogonal directions. A fatigue equation is developed by modifying the classical Aas-Jakobsen S-N equation for taking into account the effect of the confined stress on fatigue strength of plain concrete. The results of variable-amplitude fatigue tests indicate that the linear damage theory proposed by Palmgren and Miner is unreasonable in the biaxial stress state. A nonlinear cumulative damage model that could model the effects of the magnitude and sequence of variable-amplitude fatigue loading and lateral confinement pressure is proposed on the basis of the evolution laws of the residual strains in the longitudinal direction during fatigue tests. The residual fatigue life predic  相似文献   

Modelling of flow around a near-bed pipeline with a spoiler   总被引：1，自引：0，他引：1  

L. Cheng  L. W. Chew 《Ocean Engineering》2003,30(13):1595-1611

Flow around a pipeline with and without a spoiler near a smooth wall is simulated by solving the Navier–Stokes equations. Finite-difference formulation with a second-order upwind scheme in a curvilinear coordinate system is employed. The influences of the spoiler on hydrodynamic forces, pressure distribution, vortex shedding frequency, velocity profile under the pipe, as well as shear stress on the wall are investigated. The attachment of a spoiler significantly increases drag, root-mean-square (RMS) lift, flow through the gap between the pipe and the wall and shear stress on the seabed around the pipe. The spoiler also generates a non-zero mean downward force on the pipeline, which may enhance the self-burial of the pipeline.  相似文献   

关于修改港工钢筋混凝土规范小偏心受压构件正截面强度计算的建议     

王清湘 《海洋工程》1995,(2)

本文提出在小偏心受压构件正截面强度计算中，取消弯曲抗压强度ｆｃｍ（Ｒｗ），采用轴心抗压强度ｆｃ，这与构件的实际破坏形态相符。对小偏心受压构件正截面强度计算提出了设计建议。特别是对工程上大量应用的矩形截面对称配筋小偏压构件提示了简捷的设计方法，与以往的近似计算方法相比具有物理概念明确，精度高，方法简捷的特点。  相似文献   

Potential improvements to current methods of recognizing single targets with a split-beam echo-sounder   总被引：1，自引：1，他引：1  

Soule  Michael; Hampton  Ian; Barange  Manuel 《ICES Journal of Marine Science》1996,53(2):237-243

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A requiem for the use of 20 log10 Length for acoustic target strength with special reference to deep-sea fishes     

McClatchie  S; Macaulay  G.J; Coombs  R.F 《ICES Journal of Marine Science》2003,60(2):419-428

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Target strength of the lanternfish, Stenobrachius leucopsarus (family Myctophidae), a fish without an airbladder, measured in the Bering Sea   总被引：1，自引：0，他引：1  

Yasuma  Hiroki; Takao  Yoshimi; Sawada  Kouichi; Miyashita  Kazushi; Aoki  Ichiro 《ICES Journal of Marine Science》2006,63(4):683-692

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Ex situ target strength of rockfish (Sebastes schlegeli) and red sea bream (Pagrus major) in the Northwest Pacific   总被引：2，自引：0，他引：2  

Kang  Donhyug; Hwang  Doojin 《ICES Journal of Marine Science》2003,60(3):538-543

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