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161.
In consideration of the global optimization for engineering projects, a group of calculation formulas have been derived by means of theoretical derivation and model tests. On this basis, a design procedure for the distorted units is proposed, by means of which the distorted units of an anology shape and an identical porosity ratio with the original units can be obtained after conducting a distorted enlargement and a normal contraction. The stability waveheight and stability factor of the distorted unit can be calculated with the enlargement factor, a, of the horizontal dimension of the distorted unit, or with the contraction scale, A , of the contracted distorted unit. As a result, the stability of the armor unit can be significantly improved without increasing the quantity of concrete. For the same wave met by the original units, the thickness of placement of the contracted distorted unit can be obviously reduced, thus, a large quantity of concrete can be saved, consequently, economic benefit can be achieved. 相似文献
162.
Wang Jianyi
Ge Zhijin Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1993,(2)
- This paper describes the design of a permeable caisson breakwater with slanting slabs (Types I and 11) and presents some preliminary experimental results, together with relevant figures and tables. Analysis is made of the reflection coefficient, transmission coefficient, acting wave pressures, water jetting at the crest of the breakwater, and wave overtopping. Experiments show conclusively that this type of breakwater has the advantages of light dead weight, good wave-absorbing performance, low coefficients of reflection and transmission, and small wave overtopping. 相似文献
163.
164.
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
165.
Shen Ruifu Wang Hongjin Zhou Jinxing Zhou Keji
Former graduate student of Tsinghua University now works in Nanjing Hydraulic Research Institute Nanjing
Professor Tsinghua University Beijing
Senior Engineer Tsinghua University Beijing 《中国海洋工程》1994,(4)
- The cyclic rotation of principal stress direction with a constant amplitude is the characteristics of cyclic stress in seabed deposit induced by travelling waves. Presented in the paper are the results obtained from tests simulating the cyclic stress characteristics, with emphasis laid on the buildup of pore water pressure in soil samples. Regression analysis of test data shows that the pore water pressure can be expressed as the function of the number of cycles of cyclic loading, or as the function of generalized shear strain. Using the results thus obtained, the possibility of failure of seabed deposit under cyclic loading induced by travelling waves can be evaluated. The comparison with the results of conventional cyclic torsional shear tests shows that neglect of the effect of the cyclic rotation of the principal stress direction will result in considerable over-estimation of the stability of seabed deposit. 相似文献
166.
A spatial array of wave gauges installed on an observatoion platform has been designed and arranged to measure the lo-cal features of winter monsoon directional waves off Taishi coast of Taiwan. A new method, named the Bayesian Parameter Estimation Method(BPEM) , is developed and adopted to determine the main direction and the directional spreading parame-ter of directional spectra. The BPEM could be considered as a regression analysis to find the maximum joint probability of parameters, which best approximates the observed data from the Bayesian viewpoint. The result of the analysis of field wave data demonstrates the highly dependency of the characteristics of normalized directional spreading on the wave age. The Mit-suyasu type empirical formula of directional spectrum is therefore modified to be representative of monsoon wave field. More-over, it is suggested that Smax could be expressed as a function of wave steepness. The values of Smax decrease with increas-ing steepness. Finally, a local directi 相似文献
167.
对东泰气田Jp^1气藏拟定的两套开发方案从投资估算、盈利能力等技术经济角度出发,对两套开发方案进行了技术经济评价和对比分析,得出两套开发方案中更加合理的开发方案,对东泰气田蓬一气藏的勘探与开发提供了技术经济指导。 相似文献
168.
The 9th-Generation International Geomagnetic Reference Field 总被引:5,自引:0,他引:5
International Association of Geomagnetism Aeronomy Division V Working Group Participating members: S. Macmillan S. Maus T. Bondar A. Chambodut V. Golovkov R. Holme B. Langlais V. Lesur F. Lowes H. Lühr W. Mai M. Mandea N. Olsen M. Rother T. Sabaka A. Thomson I. Wardinski 《Geophysical Journal International》2003,155(3):1051-1056
169.
新场气田是四川盆地西部凹陷-典型多类型,多层系的低渗透-致密陆相碎屑岩气藏叠置而成的大气田,新场气田勘探开发各阶段中,充分应用DST测试,完井测试,压裂测试,生产试井等手段,通过对气藏(层)压力,气藏(层)温度及相应气层流体性质和流量等资料的分析来揭示气藏(层)特征及压裂开发效果是气田滚动开发较为有效的手段。 相似文献
170.
NI Jinren Professor Dept. of Geography Peking University HUI Yujia Professor Dept. of Hydraulic Engineering Tsinghua University 《国际泥沙研究》1993,(2)
I. ON THE INFLUENCING FACTORS OF THE SEDIMENT~LADEN FLOW VELOCITY PROFILEThe influence of sediment on the water--now structures must be considered when thevelocity profile of the sediment--laden now (or turbid flow) is studied. widely usedparameters for reflecting thoses influences are the sediment concentrahon and theffichardson number, where Ri represents the variation of the concentration gradient.Generally, the vertical distributions of sediment concentration and th… 相似文献