Theory and Practice of Soft Clay Engineering     

Wei Rulong Prof. Senior Engineer  Geotechnical Engineering Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1994,(1)

-The shear strength and deformation properties of soft clay are discussed first. Then some methods for predicting the performance of soft clay foundation are proposed. Finally, case histories are presented to illustrate some discussed aspects of soft clay.  相似文献   

Improved form of wind wave frequency spectrum   总被引：5，自引：0，他引：5  

Wen Shengchang 《海洋学报(英文版)》1989,8(4):467-483

The lower frequency part of the theoretical wind wave spectrum proposed by the authors (Wen et al. , 1988a, b,c) has been improved and the form of spectrum is appreciably simplified. In addition to the field data collected in the Bohai Sea region and used in the previous papers, those obtained in the Huanghai Sea, the East China Sea and the South China Sea have been employed so that the improved spectra can be verified on a more extensive observational basis. Computed results agree with the observations well. Further comparisons have been made between the proposed spectra and the JONSWAP spectrum. Though the two types of spectrum are close to each other in form, the former shows, as a whole, better agreement with the observation than the latter. By introducing an improved relation between the peak-ness factor and significant wave steepness, the spectrum contains only significant wave height and period as parameters. For spectra given in this form, the computed peak frequencies coincide approximately wit  相似文献   

The Effect of Internal Fluid on the Response of Vortex-Induced Vibration of Marine Risers   总被引：5，自引：1，他引：5  

郭海燕  王元斌傅强 《中国海洋工程》2004,18(1):11-20

Based on Iwan‘s wake oseillator model developed with the classical van der Pol equalion, the differential equation for the response of the vortex-induced vihration (VIV) of the riser considering the effect of the internal flowing fluid and the external marine environmental condition is derived. The effect of the intermal flowing fluid on the response of VIV of the riser is studied by means of the Finite Element Method. The results show that the effect of the internal fluid velocity on the VIV of the riser is strong when the natural frequency of the riser is close to the vortex shedding frequency. In addition, the increase of the top tension can decrease the sensitivity of the riser to the internal fluid velocity.  相似文献   

涠洲岛珊瑚礁生态系中浮游动植物与环境因子关系的初步探讨   总被引：2，自引：0，他引：2  

韦蔓新  黎广钊  何本茂  梁文 《海洋湖沼通报》2005,(2):34-39

本文根据1990年4月、10月间的理化分析数据，结合2002年9月涠洲岛珊瑚礁生态环境的调查状况，首次从珊瑚礁生态系的角度初步探讨该岛区浮游动植物与环境因子的关系。结果表明：该岛区浮游动植物的分布具有明显的区域性和季节性，既体现了珊瑚礁生态系具有较高的初级生产力特征，也体现了浮游动植物具有显著的季节交替现象。相关分析显示，水温、盐度、N，P，Si营养盐对浮游植物的种类组成及数量变动均有明显影响，但对浮游动物的影响不大；N是该生态系中浮游植物的限制因子，P限制状况只有在珊瑚礁生长带较深的海域出现，Si呈相对富足状态。  相似文献   

人工神经网络方法反演东中国海悬移质浓度     

李伟 《海洋湖沼通报》2007,(4):55-58

海中悬移质是决定海洋光学性质、海洋水质,河口海岸带演变动力过程的重要环境参数。本文利用模拟遥感反射比数据集建立人工神经网络反演悬移质浓度,并利用东中国海现场同步数据对该算法进行验证。  相似文献   

计算域的选取对风暴潮数值模拟的影响   总被引：3，自引：1，他引：3  

王秀芹  钱成春  王伟 《中国海洋大学学报(自然科学版)》2001,31(3):319-324

作者以 72 0 3号台风过程中引起的黄海沿岸水文测站的风暴潮过程为例 ,选取不同计算域 ,模拟计算的同一测站的风暴潮增水值有很大差异。只有选取整个黄渤海海域 ,才能得到较精确的风暴潮增水结果。从而揭示在封闭或半封闭海域中由风暴过程激发的区域自由振荡 ,是风暴潮增水中不容忽视的量。说明该海域中的风暴潮过程是海域整体效应的响应 ,因此认为数值模拟中计算域应选取整个封闭或半封闭海域  相似文献   

Investigation on the Deposition in an Excavated Trough at the East Shore of Jiaozhou Bay, China     

Zhang Jinshan Yu Guohua Research Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Research Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1995,(3)

- Based on field investigations, this paper analyzes three types of harbour basinns and navigation channel excavated on seabed in Jiaozhou Bay, get a general rule of deposition for excavated trough, it found that pollution is one of crucial factors resulting in the deposition of the excavated trough in the east shore of Jiaozhou Bay. With these results, it predicted the annual deposition thickness for the excavated trough and disclosed the fact that it can't be deposited deadly during one storm. At the same time, with two-dimensional numerical model, it studied the effects of the excavated trough and the reclamation near shore on tidal cureent and said that the excavated trough can decrease the current velocity passing through the trough about 10- 15%, but only limited inside and near the trough and there are no effect on other regions; reclamation can cut off the pollution sources and no obvious effect on the currents of the Jiaozhou Bay. Connecting the deep trough and Cangkou tidal channel with a new  相似文献   

Study on “J”Type Offshore Pipeline-Laying Method     

Liang Zheng Associate Professor  Southwest petroleum Institute  Nanchong  Sichuan Province 《中国海洋工程》1994,(2)

-Considering both the seabed foundation and wave, an analytic model of "J" type is proposed for offshore pipeline-laying. The governing differential equation is also obtained for the pipeline on the seabed and for the suspension sections. By utilizing weighted- residual method and dual iteration technique, an approximate solution is obtained, too. In the end, calculation examples are given for analyzing the changeable relationship among the major parameters.  相似文献   

Design of Mooring System for Oil Storage Vessels     

LI  Wen-long 《中国海洋工程》2003,17(4):541-550

The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results show that the mooring system has an annual reliab  相似文献   

Second-Order Wave Diffraction Around 3-D Bodies by A Time-Domain Method   总被引：1，自引：1，他引：1  

BAI  Wei 《中国海洋工程》2001,(1):73-84

A time-domain method is applied to simulate nonlinear wave diffraction around a surface piercing 3-D arbitrary body. The method involves the application of Taylor series expansions and the use of perturbation procedure to establish the corresponding boundary value problems with respect to a time-independent fluid domain. A boundary element method based on B-spline expansion is used to calculate the wave field at each time step, and the free surface boundary condition is satisfied to the second order of wave steepness by a numerical integration in time. An artificial damping layer is adopted on the free surface for the removal of wave reflection from the outer boundary. As an illustration, the method is used to compute the second-order wave forces and run-up on a surface-piercing circular cylinder. The present method is found to be accurate, computationally efficient, and numerically stable.  相似文献