Approach to Calculating Methods of Wave Breaking Depth and Height     

Wang Liang Du Heng Lecturer  Hohai University  Nanjing Engineer  Jiangsu Communication Planning  Design Institute  Nanjing 《中国海洋工程》1993,(1)

- Engineers in coastal engineering have been paying much attention to the research subject on wave breaking. In this paper, previous research results on the calculating methods of wave breaking depth and height are enumerated, the laws of wave transformation before and after wave breaking are investigated, an adequate supposition is made, and the effect of beach slope, bed friction and breaking turbulence on wave breaking is considered. By applying the theory of wave energy dissipation rate and combining with proper formulas of solitary waves, a new calculating formula of wave breaking depth and height on the movable bed is derived and examined with the data from experimental pools of different sizes, and it is proved to be of practicability.  相似文献   

Interaction Between Waves and A Comb-Type Breakwater   总被引：2，自引：1，他引：2  

DONG  Guo-hai 《中国海洋工程》2003,17(4):517-526

The characteristics of wave transmission, reflection and energy dissipation of comb-type caisson breakwaters are studied through laboratory physical model tests. Regular and irregular waves, with a wide range of wave heights and periods and a constant water depth, are considered. Different dimensions of each portion of the comb-type caisson breakwater are tested. Empirical formulae for calculating the reduction coefficient k, which is the ratio of horizontal wave force on unit length of the comb-type breakwater to that on unit length of the vertical wall breakwater, and for calculating the reflection coefficient of waves k, are obtained from the measurements. The comb-type caisson breakwater has been found to be very efficient in dissipating incident wave energy and in reducing wave reflection, and has already been used for the construction of an island breakwater in the Dayao Bay of Dalian Port, Liaoning Province, China. Compared with the cost of a common caisson breakwater, about 24. 5% of the investm  相似文献   

Fuzzy Probabilistic Analysis of Seismic Stability of Coastal Embankment   总被引：1，自引：0，他引：1  

He Guangne Yang Bin Wen Nai Professor  Dalian University of Technology  Dalian Engineer  Design  Research Institute of Shanghai Harbour Engineering  Shanghai . Lecturer  Dalian Fisheries College  Dalian 《中国海洋工程》1996,(1)

The stability of slope is affected by a number of factors, some of which have not only random property but also fuzzy characteristic. Therefore, the analysis of slope stability is really an uncertain problem. The customary safety factor does not in reality reflect stability scientifically, quantitatively and practically. In order to obtain more practical results, the slope stability is treated as a fuzzy random event for the evaluation of its fuzzy probability. Finally, the seismic stability of an existing coastal embankment is analyzed by means of the suggested fuzzy probabilistic method. It may be seen that the results of analysis can more fully represent the numerical assessment of the degree of slope seismic stability.  相似文献   

On the Vibration Reduction Effect of Offshore Platform Vibration Distribution Structure     

Chen Xueming  Li Longyuan Wang Qinjian Senior Engineer  Dept. of Naval Arch  and Ocean Engineering  Shanghai Jiaotong University  Shanghai . Senior Engineer  Bohai Oil Engineering  Design Company 《中国海洋工程》1996,(4)

Based on the Bohai ocean environment characteristics, a new platform vibration distribution structure is designed to reduce the platform vibration due to flowing ice. The effect of the earthquake wave and ocean wave load on this vibration distribution structure is considered in the design. The principal idea of this new vibration distribution structure is dividing the platform main column into the inner tube and the outer tube. The outer tube is connected with the leg pontoon by braces, while the inner tube is used to support the platform deck. The inner tube and outer tube can be connected or disconneted in the region near the water line. For evaluating the vibration reduction effect of such a structure, tests are carried out on a steel model, and the external load of flowing ice, earthquake wave and ocean wave are simulated by concentated random load applied to different points of the model. The tests are performed in water media and air media respectively. The vibration reduction effect is evaluated  相似文献   

Wind-Wave Frequency Spectra of New Dalian Port     

Weng Keqin Chen Luhua Engineer  Planning  Design Institute for Water Transportation  Ministry of Communications  Beijing 《中国海洋工程》1991,(1)

This paper, based on wave data measured with Type 956 Directional WAVE-TRACK Buoy System at new Dalian Port for a whole year, analyses the properties of the wave frequency spectra, and derives the formula for the frequency spectrum of wind-waves.  相似文献   

Hydraulic Design Method of Wave Dissipating Structure with Partially Perforated Front Wall   总被引：5，自引：0，他引：5  

Li Rongqing Engineer  The First Design Institute of Navigation Engineering of Ministry of Communictions  Tianjin 《中国海洋工程》1995,(1)

Based on the matching conditions of different fluid regions, the eigenfunction expansion method is used to develop a theoretical formula for wave reflection in front of the perforated structure with a partially slit front wall. The accuracy of the solution is verified by comparing the numerical results with experimental data. In addition, a new hydraulic design method is developed by derivation of the theoretical formula with respect to the porosity of the slit wall, and the results of this design method is drafted for harbour engineers to use.  相似文献   

The Influence of Residual Stress on Plastic Buckling of Cylindrical Shells     

Wu Lianyuan Hu Gangyi Professor  Shanghai Jiaotong University  Shanghai Engineer  Wuhan Ship Development & Design Institute  Wuhan 《中国海洋工程》1994,(2)

-This paper adopts approximate formulas for residual stresses caused by cold bending for plates with stress-strain curve form a = K n. A typical distribution of the longitudinal residual stress due to welding is also assumed. The effects of residual stress due to cold bending and welding on plastic buckling of axially compressed cylindrical shells are studied by the finite element method.  相似文献   

高喷灌浆技术在防渗加固长善垸浏阳河防洪大堤堤基中的应用     

蒋友清 《湖南地质》1999,(Z1)

高喷灌浆在长善垸浏阳河防洪大堤第四系松散地基的防渗、加固中效果显著,与其它防渗措施比较,其施工速度快,成本低,在深度覆盖层堤基防渗中显示出无可比拟的优越性。  相似文献   

开孔沉箱与斜向波作用的理论研究和实验验证   总被引：2，自引：0，他引：2  

滕斌李玉成  刘洪杰 《海洋工程》2004,22(1):37-45

应用透空壁内流体速度与壁两侧的压力差成正比的线性模型,研究了无限多个开孔沉箱在斜向波作用下的反射问题。整个流域被分成无限多个子域,在每个子域内应用特征函数展开法对速度势进行展开。对于沉箱内的波浪运动,根据沉箱位置引入相位差概念。在构造反射波模型时,考虑了结构物几何形状周期性的影响。结果表明,当孔隙系数无限大时,开孔墙前后的速度非常接近,反射系数符合能量守恒定律。在低频入射波作用下,沉箱越短,其反射系数越小,反射系数随着角度的变大而减小。  相似文献   

Variation characteristics of temperature and moisture content of seasonal frozen soil during freezing process in Changchun,China     

WANG Qing  FAN Jianhua  FANG Ming  ZHANG Li .College of Construction Engineering  Jilin University  Changchun  China .China Northeast Municipal Engineering Design  Research Institute  Changchun  China 《东北亚地学研究》2009,12(1):13-16

In China, seasonal frozen soil is widely distributed. The freezing damage of subgrade soil in Jilin Province has been one of major engineering geological problems troubling the safety of road, in which some common damage phenomena, such as frost heave, subsidence deformation and frost boiling, are all caused by water translocation. Aiming at the phenomenon, the changes of moisture content of seasonal frozen soil in Changchun City are mainly studied by long-term field observation and indoor testing of physical properties under different conditions, and then the variation characteristics of moisture content in soil under different compactness and temperature conditions are realized. The results show that the increasing section of moisture content and negative temperature section all lie in O. 0 - 1.0 m of subgrade. Both lowest air and earth temperature occur in January to February, and the most negative temperature ranges from -7℃ to -10℃.  相似文献