Stress Sharing Behavior and Its Mechanism during Consolidation Process in Composite Ground Improved by Sand Compaction Piles with Low Replacement Area Ratio     

S. -K. You  K. Oda  T. -H. Kim 《Marine Georesources & Geotechnology》2006,24(4):287-304

In order to accurately design a sand compaction pile (SCP) with low replacement area ratio, it is important to understand the mechanical interaction between the sand pile and clay ground and its mechanism during consolidation process in composite ground. In this article, therefore, a series of numerical analyses on composite ground improved by SCP with low replacement area ratio were carried out. The applicability of numerical analyses, in which an elasto-viscoplastic consolidation finite element method was applied, were confirmed by comparing the results obtained from a series of laboratory model tests with the composite ground improved by SCP. Through the results of the numerical analyses, mechanical behavior of the sand pile and clay in composite ground during consolidation is elucidated, together with a stress sharing mechanism between sand pile and clay.  相似文献   

泉州湾围海工程对海洋环境的影响   总被引：17，自引：3，他引：17  

陈彬  王金坑  张玉生  唐森铭  林景宏  郑凤武  张继伟 《台湾海峡》2004,23(2):192-198

采用现场调查资料与历史资料对比的方法,从海岸和海底地貌、水环境质量、海洋生物种类和群落结构等几方面分析了近几十年来福建泉州湾围海工程的环境效应.结果表明,围海工程促进了海滩的淤浅,减小了内湾的纳潮量和环境容量,使得泉州湾内湾水质恶化;其最终后果为围海工程附近海区生物种类多样性普遍降低,优势种和群落结构发生改变.  相似文献   

东南沿海海堤现状调研报告（福建部分）   总被引：1，自引：0，他引：1  

段祥宝  毛佩郁  毛昶熙 《海洋工程》1996,(3)

这部分是福建省正在建设中的四大海堤现状调研，包括达标设计各项指标及其加高加固的技术经验。同时调研了围海工程堵口海堤的施工过程，并对灌砂防渗措施加以评述。最后介绍了兴化湾的莆田海堤试验站和木兰陂水利工程  相似文献   

A Numerical Model of Coastal Processes of Sand Beaches Based on Long-Term Wave Series     

Zhang Changkuan  Wang Zhen  Zhang Dongsheng Associate Professor  Dept. of Navigation  Ocean Engineering  Hohai University  Nanjing Lecturer  Dept. of Navigation  Ocean Engineering  Hohai University  Nanjing Professor  Dept. of Navigation  Ocean Engineering  Hohai University  Nanjing 《中国海洋工程》1995,(2)

A numerical model of shoreline change of sand beaches based on long-term field wave data is proposed, the explicit and implicit finite difference forms of the model are described, and an application of the model is presented. Results of the application indicate that the model is sensitive to the order of the input wave data, and that the effects of long-term wave series and the effects of the mean annual wave conditions on the model are different. Instead of a single wave condition, the wave series will make the calibration and the verification of the model more practical and the results of the model more reasonable.  相似文献   

Sediment-starved sand ridges on a mixed carbonate/siliciclastic inner shelf off west-central Florida     

S. E. Harrison  S. D. Locker  A. C. Hine  J. H. Edwards  D. F. Naar  D. C. Twichell  D. J. Mallinson 《Marine Geology》2003,200(1-4):171-194

High-resolution side-scan mosaics, sediment analyses, and physical process data have revealed that the mixed carbonate/siliciclastic, inner shelf of west-central Florida supports a highly complex field of active sand ridges mantled by a hierarchy of bedforms. The sand ridges, mostly oriented obliquely to the shoreline trend, extend from 2 km to over 25 km offshore. They show many similarities to their well-known counterparts situated along the US Atlantic margin in that both increase in relief with increasing water depth, both are oriented obliquely to the coast, and both respond to modern shelf dynamics. There are significant differences in that the sand ridges on the west-central Florida shelf are smaller in all dimensions, have a relatively high carbonate content, and are separated by exposed rock surfaces. They are also shoreface-detached and are sediment-starved, thus stunting their development. Morphological details are highly distinctive and apparent in side-scan imagery due to the high acoustic contrast. The seafloor is active and not a relict system as indicated by: (1) relatively young AMS ¹⁴C dates (<1600 yr BP) from forams in the shallow subsurface (1.6 meters below seafloor), (2) apparent shifts in sharply distinctive grayscale boundaries seen in time-series side-scan mosaics, (3) maintenance of these sharp acoustic boundaries and development of small bedforms in an area of constant and extensive bioturbation, (4) sediment textural asymmetry indicative of selective transport across bedform topography, (5) morphological asymmetry of sand ridges and 2D dunes, and (6) current-meter data indicating that the critical threshold velocity for sediment transport is frequently exceeded. Although larger sand ridges are found along other portions of the west-central Florida inner shelf, these smaller sand ridges are best developed seaward of a major coastal headland, suggesting some genetic relationship. The headland may focus and accelerate the N–S reversing currents. An elevated rock terrace extending from the headland supports these ridges in a shallower water environment than the surrounding shelf, allowing them to be more easily influenced by currents and surface gravity waves. Tidal currents, storm-generated flows, and seasonally developed flows are shore-parallel and oriented obliquely to the NW–SE trending ridges, indicating that they have developed as described by the Huthnance model. Although inner shelf sand ridges have been extensively examined elsewhere, this study is the first to describe them in a low-energy, sediment-starved, dominantly mixed siliciclastic/carbonate sedimentary environment situated on a former limestone platform.  相似文献   

A Numerical Study on the Structure and Dynamics of Turbulence in Oscillatory Bottom Layer Flow over A Flat or Rippled Bed     

白玉川  吴朝安黄涛 《中国海洋工程》2006,20(1):45-60

1 .IntroductionUnder the influence of surface waves ,sandripples often appear on beaches . Whenthe amplitudeof water oscillationis sufficientlylarge ,vortices are formed onthe lee of every sand ripple crest . A-mongthese vortices ,the most important are t…  相似文献   

青岛市水环境污染及其防治对策     

赵秀春  初日邦  王成见  尚庆国 《海岸工程》2002,21(3):50-54

通过分析近几年青岛市地表，地下水水质监测资料，总结水环境污染地区分布规律，摸清水环境污染形成原因，对当前防污治污工作提出了对策建议。  相似文献   

珠江三角洲及珠江口海区的空气微生物含量     

陈皓文 《热带海洋学报》1996,(3)

１９９４年６，７月，调查了广州、深圳、珠海及珠江口海区的空气微生物粒子沉降量状况。发现空气微生物粒子总量、真菌粒子量、真菌粒子数／总菌粒子数百分比在三市中不一致。这三种数据一般是陆上的高于海上。随着距陆的增加，都市影响的减弱和海面的开阔，空气微生物含量呈减少之势，显示出海洋新鲜空气对陆上污染空气的调节、净化作用。文中还分析了空气微生物有关参数与气温、风力或相对湿度间的相关关系。  相似文献   

砂质海岸岸滩侵蚀演变模式探讨——以山东南部海岸侵蚀岸段的岸滩演变为例   总被引：5，自引：0，他引：5  

包四林虞志英  刘苍字张国安 《海洋工程》2003,21(3):94-99

在分析山东南部海岸几十年来的地形观测资料的基础上，运用砂质海岸等深线变化预测理论，建立该区的岸滩侵蚀演变预测模型，研究了该区域岸滩演变规律。实测资料验证表明：预测结果合理，基本反映了本区岸滩演变的特征。  相似文献   

开发胶东温泉地热水对环境的影响   总被引：1，自引：0，他引：1  

栾光忠  范德江 《中国海洋大学学报(自然科学版)》1994,(Z3)

根据地热水中阴离子的组分与温泉水类型，指出其中Ⅱ＿１、Ⅱ＿２：型水温高，日采水量大，矿化度高，水质复杂，相应的环境效应明显．提出地热水的大规模开采以及尾水的大量排放，对温泉周边的生态环境、工程环境、土壤及地下水等方面有明显的影响．  相似文献