Manned Testing of the Diver Gas Recovery Installation     

Mao Fangguan  Lu Shunchang Luo Ruiren Senior Engineer  Naval Medical Research Institute  P. L. A. of China  Shanghai  Senior Engineer  Navigation Guarantee 《中国海洋工程》1995,(4)

The Diver Gas Recovery Installation (DGRI) was evaluated at 80 msw saturation - 100 msw excursion diving on HeO2 in the Naval Medical Research Institute (NMRI) of China in April, 1995. The diving depth, lockout time, breathing gas flow rate and consumption, inspired oxygen partial pressure (PO2) and carbon dioxide partial pressure (PCO2) were monitored. The results indicated that PO2 was controlled to fluctuate from 64.3 to 84.0 kPa and PCO2 went up from 0.01 kPa up to O.I kPa during 4 hours excursion diving; recovery of breathing gas reached 95%; three divers felt well and breathed comfortably during simulating heavy work. The test showed that it met desired performance goals. The DGRI is a kind of important equipment for long duration deep dive. It enables the gases exhaled by the divers to be re-cycled, and therefore it has great social, military and economic significance for diving operation and submarine rescue.  相似文献   

Underwater Explosion Treatment of Marine Soft Foundation   总被引：11，自引：0，他引：11  

Zheng Zhemin  Yang Zhengsheng Jin Liu Professor  Academician of Chinese Academy of Sciences  Director of Mechanics Institute of Chinese Academy of Sciences  Beijing Professor  Mechanics Institute of Chinese Academy of Sciences  Beijing Senior Engineer  Lianyungang Harbor Construction Command Post  Lianyungang  Province of Jiangsu 《中国海洋工程》1991,(2)

The consolidation of soft foundation is a problem that commonly appears in harbor construction engineering on muddy coast. Introduced in this paper is the experimental study on underwater explosion treatment of soft foundation, including the regulations of explosion hollow development and medium movement, the law of similarity of densification and settlement of filled stone mass by shock wave pressure and explosion energy and their construction technologies, etc. A number of projects have been completed by applying this new technique, and the technique itself has been proved practicable.  相似文献   

Safety Level and Reliability Index for Bank Slope Stability     

Mai Yuanjian Senior Engineer  the th Harbour Engineering Bureau  The Ministry of Communications of P. R. China  Guangzhou 《中国海洋工程》1997,(2)

Based on statistics and analysis of the safety factor of unstable bank slopes,the relation be-tween safety level and reliability index of stability is studied and discussed,and then the elementary cali-brating calculation is carried out to the levels of safety and reliability for bank slope stability in the rangeof safety factors stipulated in existing China Technical Specifications for Port Engineering—FoundationPart(1987)and to those reached by some stable bank slopes already built.The results show that the relia-bility index β in the effective stress method is able to reach a high value of 2.4～4.1(mid-value 3.25),while the value of β in other three kinds of total stress method can just reach a lower value of 0.5～2.8(mid-value 1.65),which are in conformity with the engineering experience in China,and thus acceptable.Some suggestions are also given in this paper to the adoption of the value of β_0—objective reliability indexfor bank slope stability.  相似文献   

Water Wave Refraction and Diffraction over Frictional Topography     

Zuo Qihua  Yao Guoquan Ding Bingcan Senior Engineer  Nanjing Hydraulic Research Institute  Nanjing Engineer  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1993,(1)

- This paper considers the effects of wave energy dissipation induced by sea-bottom friction on the computational results of water wave refraction and diffraction with the parabolic equation method. The presented results show that the friction factor formula adopted in this paper is of higher numerical accuracy than that introduced by Dalrymphe (1984), and it can be used to compute wave propagation over large open areas.  相似文献   

Reliability Index of Caisson Breakwaters for Load Variables Correlated   总被引：1，自引：0，他引：1  

郄禄文  李炎保 《中国海洋工程》2004,18(4):577-584

In order to suit the condition that the wave uplift is correlated with the horizontal wave load acting on a vertical breakwater, a generally used method for determining the reliability index β of the breakwater, i.e. the Hasofer-Lind method, is extended in a generalized stochastic space for correlative variables. The computational results for a caisson breakwater indicate that the value of β for the case of correlated variables is obviously smaller than that for the case of independent variables.  相似文献   

Numerical Study on the Probability of Fatigue Failure of a Semi-Submerged Platform Structure     

Yu Jianxing  Hu Yunchang  Wang Yehong  YuHongjie Associate Professor  Tianjin University  Tianjin  Professor  Tianjin University  Tianjin  Postgraduate for Master Degree  Tianjin University  Tianjin 《中国海洋工程》1994,(4)

On the basis of Miner's linear cumulative damage theorem, random variables are introduced to evaluate objectively the fatigue damage of a semi-submerged platform structure and a method is presented to analyze the fatigue reliability of the structure in its design life. The reliability of the method is verified through numerical examples and some conclusions are drawn, which have certain guiding and reference value for design and inspection.  相似文献   

Nonlinear Analysis of Nearshore Wave Height Variation Due to Shoaling     

Shen Xianrong Engineer  Zhejiang Provincial Design Institute of Communications  Hangzhou 《中国海洋工程》1995,(4)

Wave formulae derived from the dispersion relation for cnoidal waves are used to find an analytical solution to the problem of nearshore wave height variation on a simple topography, i. e., with an incrementally constant slope. The solution accounts for shoaling, frictional dissipation and will be sufficiently accurate for practical purposes considering the simplified assumptions which are necessary for the treatment of this problem by any method.  相似文献   

Coupled BEM-FEM Analysis of the Large-Diameter Cylinder Structure System   总被引：2，自引：0，他引：2  

Zhou Xireng  Duan Xudong  Sang Xuezhu Zhang Rui  Dai Jialu Professor  Tianjin University  Tianjin Engineer  Xiamen Port Office  Fujian Lecturer  Tianjin University  Tianjin Senior Engineer  Tianjin Port Office  Tianjin 《中国海洋工程》1992,(2)

A method of coupled BEM-FEM analysis for the elastic spatial structure system is presented. It can be applied to the calculation of the stress and deformation of the large-diamater cylinder structure system and it is suitable for symmetric or non-symmetric structures under the distributed or concentrated load. Numerical examples show that the proposed method and computer program BEFEM are quite efficient in the analysis of the large-diameter cylinder structure problems in ocean engineering.  相似文献   

Method to Determine Depositional Range of Sediment Transported from Multiple Sources in Water Area   总被引：1，自引：0，他引：1  

Ying Qiang  Jing Fei Ma Jin Rong Engineer  Nanjing Hydraulic Research Institute  Nanjing Lecturer  Nanjing College of Navigation Engineering  Nanjing Assistant Engineer  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1995,(3)

- The sediment from different sources have different content of the characteristic elements. According to the fuzzy mathematical theory, corresponding calculation and cluster analysis of each sediment sample are carried out, so the main courses of sediment transport in water area can be obtained. The characteristics of sediment from different sources are analysed. It is found that the sediment deposited of certain point in water area is due to the sources' contributions which can be calculated by the formula derived in this paper. Based on the distribution of the contribution values, the depositional range of sediment from each source can be determined. The depositional range in Huangmao Bay is determined as an example.  相似文献   

A New Method of Surveying Underwater Parts of Self Elevating Drilling Platform     

Cong Zheyan Ji Liangying Senior Engineer  Bohai Engineering & Design Company  Shanghai Senior Engineer  Shanghai Shipyard  Shanghai 《中国海洋工程》1991,(1)

It is a new method of surveying leg spuds of self-elevating drilling platforms to lift them out of water with the help of additional middle guide blocks. Its main advantages in comparison with other methods normally used up to now are: less expensive, time saving, no need for specially designated water area, direct visual observation, good reliability and safety. The working principle has been presented with the example of two platforms "Bohai No. 8" and "Bohai No. 10", to which the method was used. Also a comprehensive comparison with other methods in technological and economical aspects is given in the paper.  相似文献