Computation of Design Load and Motion for Floating Structures Navigating in Waves

—Analytical and numerical investigation is made of the source potential for floating structurewith forward speed in waves.A particular form is selected for numerical applications,where the double in-tegral of the Green function is transformed into the single one and the oscillation characteristics forintegrands in the specific computation domain are treated numerically.A comparison of calculated exam-p1es with published data is given and it shows that the numerical simulation is satisfactory and the accura-cy is adequate to engineering application.     

Study on Hydrodynamic Characteristics of Pipelines in Open Trenches

Based on hydrodynamic model tests,the relationship between relative hydrodynamic coefficientand cycle coefficient K_c is obtained by introducing the relative trench shape coefficient α_r;there is a goodrelation for the shallow trench.According to α_r of the designed trench shape and pre-chosen K_c,the reduc-tion coefficient and sheltering effect can be decided by the result provided in this paper.     

Characteristics of Landslides Induced by the Great Wenchuan Earthquake

The great Wenchuan (汶川) earthquake induced a large quantity of landslides. They are widely distributed and caused tremendous damages. The sliding mechanism and characteristics of these earthquake-induced landslides are different from those of conventional gravity landslides. Their occurrences are apparently controlled by the powerful earthquake, and they are characterized by high potential energy sliding and ejection sliding. In this article, the earthquake-induced landslides are classified, the characteris...     

Experimental Study on Free Spanning Submarine Pipeline Under Dynamic Excitation

Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is con-structed in a seismically active region. The model experiment is performed on an underwater shaking tahle to simulate the response of submarine pipelines under dynamic input. In consideration of the effects of the terrestrial and submarine pipeline , water depth, support condition, distance from seabed, empty and full pipeline, and span on dynamic response, 120 groups of experiments are conducted. Affecting factors are analyzed and conclusions are drawn for reference. For the con-trol of dynamic response, the span of a submarine pipeline is by far more important than the other factors. Meanwhile, the rosponse difference between a submarine pipeline under sine excitation and that under random excitation exists in ex-periments.     

坡顶住宅开裂原因探讨

由于边坡挡土墙设计失误、基础施工影响及原事故处理不当等原因,造成施工地段桩基-地基土-挡土墙体系超量位移,从而导致桌坡顶住宅楼开裂。通过在相应部位施工钻孔灌注桩,完善相关排水、隔水系统等措施,使住宅和边坡达到稳定。由此,应引起工程界对坡顶建筑-基础-地基土-边坡支护体系相互作用机理相关问题的重视。     

A VERIFICATION ON DIVISION OF HYDROCLIMATIC AREA IN CHINA SEAS USING DIGITAL CHARACTERISTIC OF FREQUENCY DISTRIBUTION

Ｉ.ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｄｉｖｉｓｉｏｎｏｆｈｙｄｒｏｃｌｉｍａｔｉｃａｒｅａ,ｈｏｗｔｏｓｅｌｅｃｔｔｈｅｐｒｉｎｃｉｐａｌｃｌｉｍａｔｉｃｆａｃｔｏｒｓｗｈｉｃｈｍａｙｉｎｆｌｕｅｎｃｅｔｈｅｄｉｓｔｒｉｂｕｔｉｏｎｏｆｈｙｄｒｏｃｌｉｍａｔｉｃｔｙｐｅｉｓａｎｉｍｐｏｒｔａｎｔｐｒｏｂｌｅｍｔｏｅｆｆｅｃｔｔｈｅｒｅｌｉａｂｉｌｉｔｙｏｆｔｈｅｒｅｓｕｌｔｏｆｄｉｖｉｓｉｏｎｏｆｈｙｄｒｏｃｌｉｍａｔｉｃａｒｅａ.Ｉｎｇｅｎｅｒａｌ,ｔｈｅｃｌｉｍａｔｉｃｃｈａｒａｃｔｅｒｉｓｔ…     

趋势面分析在洪山殿矿区构造和厚煤带分布研究中的应用

通过对洪山殿矿区龙潭组Ⅳ煤层底板高程趋势面分析，认为在洪山殿矿区存在多方向的褶皱及其叠加。与本区受到多期次的构造应力场作用相吻合。而通过对Ⅳ煤层厚趋势面分析，得出的煤层厚度在褶皱轴部加厚，翼部变薄的规律性可用来预测矿区Ⅳ煤层厚度和构造的变化。     

城市地籍测量中GPS技术的应用研究

GPS新技术的出现,可以高精度地测定地物点的坐标。特别是应用RTK新技术,依据一定数量的基准控制点,便可以高精度并快速地测定界址点及地物点的坐标。本文尝试利用GPS技术在城市地籍测量方面的应用做一些探讨。     

中国石油安全评价及建议

石油安全对一个国家的经济发展具有重大意义。随着中国经济的持续快速增长,以及受国内石油资源短缺、石油地缘政治等因素的影响,国内石油供需矛盾进一步加剧,石油安全问题日益显现。为科学地评价中国石油安全的程度,先从国内资源禀赋、国内生产能力、国际市场可得性和国家应急保障能力4个方面设计了石油安全评价指标体系;然后,再采用德尔菲法、主成分分析法,选取国内原油储采比、国内原油储量替代率、国内石油消费对外依存度、国内石油进口集中度、国际原油价格和国内石油储备水平6个要素指标,构成一个新的综合指标,即石油安全度;最后,以石油安全度为工具,对中国近年来石油安全的形势进行了定量评价。