Full scale decay test of a tanker: field data and theoretical analysis

This paper presents results from a full scale decay test made with a tanker in a relatively protected area in the Brazilian coast. In at least two tests the environmental loads (wind, waves and current) were very small and the time history of the surge motion was well behaved, making it possible to check some proposed models for the damping in the hull and mooring lines. Field data seem to confirm that the damping is indeed of the fluid viscosity type and the theoretical models are able to recover roughly 75% of the observed damping, the energy dissipation in the mooring lines being, by far, the major contribution. The remaining 25% are likely due to non modeled effects, such as the environment influence, which although small and not measured certainly exists, and to the friction between the mooring lines and the seabed.     

三传感器波浪水槽二次反射主动吸收方法

三传感器波浪水槽二次反射主动吸收方法是加拿大科学院水力中心最近开发的一种水槽反射波控制技术。该法在造波板前 1～ 2倍波长处布置 3个传感器 ,通过入反射波分离方法得到准确的入反射波参数 ,以此调整造波信号 ,有效地吸收由建筑物反射回到造波板的二次反射波。文中在分析波浪水槽二次反射吸收方法研究现状的基础上 ,介绍了加拿大水力中心对现有方法的改进及其效果     

锦州湾沾污沉积物急性毒性的海洋端足类检验

１９９２年９月￣１９９３年１月对锦州湾沾污沉积物的海洋端足类急性毒性效应进行了研究。从锦州湾湾顶到湾口沿西南－－东北方向每２ｋｍ等距离采集２７个表层沉积我校 品,应用海洋端足类Ａ ｍｐｅｌｉｓｃａ ａｂｄｉｔａ对这些样品进行了１０ｄ直流式急性毒性检验,检验指标为死亡率。结果表明,五里河河口处受试生物死亡率最高,为１００％,从湾顶该河口处沿东北方向随着距离增加,死亡率逐渐递减,笔架山处最低,仅为２．     

桶形基础沉贯室内模型试验研究

桶形基础采用负压沉贯法施工,其贯入阻力与压桩,打桩等施工方法显著不同。本文介绍了在粉土和粉质粘土地层中的一组模型试验情况,认为负压法施工可显著降低粉土的抗贯阻力,但在粉质粘土中减阻效果不明显。     

玻璃钢渔船总纵弯曲的实船试验研究

本文通过实船试验研究玻璃钢渔船的总纵弯曲,以求得玻璃钢渔船应变和挠度随载荷的变化特性,从而了解玻璃钢渔船的总纵强度。     

采油平台淘空防护措施的试验研究

通过室内试验,研究了采油平台的冲淘机理和防护措施,对仿生海底、仿生林、抛石块、抛石子袋等防冲淘措施进行了方案设计和试验,完成了导管架式、桶形基础式、沉垫式3种采油平台的冲淘及防护措施试验研究,提出和完善了多层次抛石防护技术,并将研究成果成功应用于海上防护工程.提出的研究思路以及得到的研究成果,对解决胜利油田海区粉土地基的防冲淘难题具有重要指导意义.     

FPSO甲板上浪研究现状

浮式生产储油轮（FPSO）是当今海洋石油开发的主流设施。FPSO通常采用单点系泊系统,船首暴露在波浪作用下,定位于特定海域进行长达数年的长期作业,上浪的风险很大。甲板上浪及其产生的载荷已是当前国际FPSO工程和研究领域的热点之一。介绍了国内外在试验研究和理论研究两方面对FPSO甲板上浪研究的进展情况,并建议我国开展这方面的研究。     

水深对超大型FPSO波浪载荷响应影响试验研究

随着超大型浮式生产储卸油装置FPSO（floating production storing and offloading）在渤海浅水海域的广泛应用,水深对FP—SO波浪载荷响应的影响问题突现出来。对缩尺比为1：100的三模块分节模型进行了水深对超大型FPSO波浪载荷响应影响的试验研究,试验结果表明水深对FPSO波浪诱导载荷的影响很大。     

圆弧板透空式防波堤消波性能试验研究

提出了一种由多层圆弧板组成的新型透空式防波堤结构,并对其在二维规则波浪作用下的消波性能进行了物理模型试验研究。在不同入射波高条件下,对圆弧板和水平板透空结构的消波性能进行了比较分析,探讨了圆弧板间距和层数对圆弧板透空式结构消波性能的影响。研究结果表明,圆弧板透空式结构的消波效果优于水平板式透空结构,在相对宽度为0.2时,可以使透射系数达0.5以下。随着圆弧板间距从0.15 m减小到0.05 m时,消波效果逐步提升,而圆弧板的层数对结构的消波性能也有一定影响。     

Centrifugal test of a road embankment built after new dredger fill on thick marine clay

Abstract

The construction of a 100-km road network is planned on a land reclamation area in the Oujiang Estuary in China. The embankment had a height of 4 m and a base width of 60 m. The reclamation area is newly filled by a 3-m dredger fill on a 48-m thick layer of marine clay. Estimation of the settlement of the future road network is difficult. To guide the construction of the road network, a 1/100-scale centrifuge model test was performed with a marine clay sample from the construction site to simulate the layered settlements and evaluate the drainage effect of prefabricated vertical drains in the dredger fill in the following 10 years. The results of the centrifuge modeling test are verified by 10-month in situ monitoring, which shows agreement between the centrifuge modeling test results and the in situ results. The test results indicate that additional time is needed to reinforce the newly added dredger fill by the surcharge preloading method to uplift the elevation of the reclamation area with dredger fill.