Determination of Shaft Capacity for Pile under Cyclic Axial Loading in Clay     

Chen Zhuchang Jing Yongxi Professor  Tongji University  Shanghai Engineer 《中国海洋工程》1991,(1)

For load-controlled and displacement-controlled test data of piles cyclically axially loaded in clay, the displacement conditions are suggested for determining the shaft capacity. According to the suggested displacement conditions, not only the results of shaft capacity from laboratory model piles are close to those from in-situ piles, but also the results of load-controlled tests are in satisfactory agreement with those of displacement-controlled tests. Moreover, based on the test data of laboratory model piles in combination with the test data published, the paper suggests the values of the normalized shaft capacity of piles under a variety of static and cyclic loading combinations.  相似文献   

Nonlinear Dynamic Analysis of Flexible Marine-Risers     

Chen Jiajing  Wang Dongjiao Professor  South China University of Technology  Guangzhou PhD Student  Hong Kong Polytechnic  Formerly  South China University of Technology  Guangzhou 《中国海洋工程》1991,(4)

A nonlinear dynamic analysis model is estabilished on the basis of "lumped mass" approach, which takes the influence of the fluid flow within the pipe into consideration. Numerical results are compared with the published works, and the effects of internal fluid flow, internal pressure, dyanmics as well as the nonlinear characteristics on the behavior of flexible risers are discussed. From this work, some useful conclusions are drawn.  相似文献   

An Analytic-Numerical Solution of Wave Transformation     

Feng Weibing Hong Guangwen Ph. D Student  Hohai University  Nanjing . Professor  Hohai University  Nanjing 《中国海洋工程》1995,(1)

An analytic-numerical solution of wave transformation in shoaling water is presented in this paper. The analytical expression for wave heights along the wave rays is derived in consideration of the combined effect of water depth shoaling, the wave refraction and the sea bottom friction. The wave rays (orthogonals) are calculated by a fourth order Runge-Kutta algorithm and the wave crest lines are computed by an iteration procedure. The numerical results are compared with analytical solution for a special case of parallel- straight contour shore and field data, and comparisons show that the proposed mathematical model and computation method are very useful and convenient for engineering application.  相似文献   

Transformation of Wave Energy Spectrum in Shallow Water     

Xue Hongchao  Su Dehui Xu Fumin Professor  Research Institute of Coastal  Ocean Engineering  Hohai University  Nanjing Doctor  Dept. of Navigation  Ocean Engineering  Hohai University  Nanjing Ph. D. Student  Dept. of Navigation  Ocean Engineering  Hohai University  Nanjing 《中国海洋工程》1995,(3)

- Combined with irregular wave-maker, the growing process of Wave Energy Spectrum in shallow water can be studied in wind wave channel on different water depth conditions, and its transformation characteristics and rules can be obtained.  相似文献   

Investigation of Internal Turret Mooring System for Oil Production Storage Vessels     

Ma Zhiliang  Huang Xianglu  Ma Peisun Fan Genfa  Yu Xiangsan  Jin Dexian Professor  Shanghai Jiao Tong University  Shanghai Associate Professor  Shanghai Jiao Tong University  Shanghai Research Fellow  Shanghai Jiao Tong University  Shanghai 《中国海洋工程》1991,(4)

  相似文献   

Finite Element Analysis of soft Foundation Strengthening by Vacuum Loading from Lower Position     

Qiu Changlin Yan Shuwang Ph. D. Student  Dept. of Hydraulic Engrg.  Tianjin University  Tianjin Professor  Dept. of Hydraulic Engrg.  Tianjin University  Tianjin 《中国海洋工程》1997,(1)

Strengthening soft foundation by vacuum loading from lower position is a new method of ac-celerating the consolidation of dredger fill.This paper presents the mechanism of soft foundation strength-ening by vacuum loading from lower position and evaluates the effectiveness of this method under variousboundary conditions by means of finite element method(FEM)on the basis of Biot's consolidationtheory.  相似文献   

High-Order Models of Nonlinear and Dispersive Wave in Water of Varying Depth with Arbitrary Sloping Bottom   总被引：4，自引：0，他引：4  

Hong Guangwen Professor  Coastal  Ocean Engineering Research Institute  Hohai University  Nanjing  P. R. China. 《中国海洋工程》1997,(3)

High-order models with a dissipative term for nonlinear and dispersive wave in water of va-rying depth with an arbitrary sloping bottom are presented in this article.First,the formal derivations toany high order of μ(=h/λ,depth to deep-water wave length ratio)and ε(=α/h,wave amplitude todepth ratio)for velocity potential,particle velocity vector,pressure and the Boussinesq-type equations forsurface elevation η and horizontal velocity vector U at any given level in water are given.Then,the exactexplicit expressions to the fourth order of μ are derived.Finally,the linear solutions of η,U,C(phase ce-lerity)and C_g(group velocity)for a constant water depth are obtained.Compared with the Airy theory,excellent results can be found even for a water depth as large as the wave legnth.The present high-ordermodels are applicable to nonlinear regular and irregular waves in water of any varying depth(from shal-low to deep)and bottom slope(from mild to steep).  相似文献   

Investigation on Settling Characteristics of Floes in the Changjiang Estuary, China     

Li Yan  Wang Yaqin LinYian Associate Professor  Second Institute of Oceanography  State Oceanic Administration  Hangzhou  Senior Engineer  Second Institute of Oceanography  State Oceanic Administration  Hangzhou 《中国海洋工程》1995,(3)

- Settling characteristics of floes, including relative settling velocity, relative flocculation coefficient and flocculation exponent, are obtained by the suspended load equations for different size fractions. Data of the Changjiang Estuary suggest that level of flocculation changes from river section, river mouth (turbidity maximum) to offshore area in sequence of low, very high and high. The settling characteristics of floes reflected by in situ estimation performs a similar feature as that obtained from still water experiment.  相似文献   

The New Form of Time-Dependent Mild Slope Equation for Random Waves     

Zhang Yonggang  Li Yucheng Teng Bin Doctor Degree Candidate  The National Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian Professor  The National  Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian Associate Professor  The National Key Laboratory of Coastal  Offshore Engineering  Dalian University of Technology  Dalian 《中国海洋工程》1995,(4)

The mild-slope equation derived by Berkhoff (1972), has widely been used in the numerical calculation of refraction and diffraction of regular waves. However, it is well known that the random sea waves has a significant effect in the refraction and diffraction problems. In this paper, a new form of time-dependent mild slope equation for irregular waves was derived with Fade approximation and Kubo's time series concept. The equation was simplified using WKB method, and simple and practical irregular mild slope equation was obtained. Results of numerical calculations are compared with those of laboratory experiments.  相似文献   

Design Curves for Mooring Lines of Turret Mooring Systems   总被引：1，自引：0，他引：1  

Gao Jie Tan Jiahua Chen Xiaohong Associate Professor  Shanghai Jiao Tong University  Shanghai Professor  Shanghai Jiao Tong University  Shanghai Lecturer  Shanghai Jiao Tong University  Shanghai 《中国海洋工程》1997,(4)

This paper presents a series of design curves to aid in the selection of turret mooring systemsfor tankers based Floating Production Storage and Offloading(FPSO)systems.These curves are appropri-ate to water depths ranging from 100m to 600m.The curves can be used as a preliminary design tool,al-lowing the designer to quickly evaluate alternative mooring system configurations,including the numberof mooring lines,the characteristics of chain and wire rope to be deployed and the initial tension.With aknowledge of the total environmental force and vessel motion characteristics,the designer can determinethe appropriate system for closer evaluation.  相似文献