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

Fayun Liang  Mingyi Zhao  Chengrui Qin  Yajie Jia  Zhongwei Wang  Guiping Yue 《Marine Georesources & Geotechnology》2020,38(1):114-121

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.  相似文献   

Spatial patterns and environmental risks of ringnet fishing along the Kenyan coast     

P Thoya  S Pérez-Jorge  GM Okemwa  H Mwamlavya  A Tuda  N Wambiji 《African Journal of Marine Science》2020,42(1):23-33

Ringnet fishing began in the early 20th century and is practised worldwide, mainly to target nearshore pelagic species. The method was introduced to Kenya’s coastal waters by migrant fishers from Tanzania. However, the impacts of this fishing gear remain poorly assessed. We assessed the spatial distribution of ringnet fishing effort and its possible effects on ecosystem components, such as coral reefs, marine megafauna and marine protected areas, on the south coast of Kenya. We tracked 89 ringnet fishing trips made from December 2015 to January 2016 and used spatial multicriteria analysis to determine hotspots of possible environmental risks. The results showed that habitat type and bathymetric profile influenced the spatial distribution of ringnet fishing effort. Mixed seagrass and coral habitats had the highest concentration of the effort. Most of the habitats in the study area were moderately exposed to the impacts of the ringnet fishery. The study identifies high-risk areas that require spatial measures to minimise possible environmental risks of the gear both to habitats and to endangered sea turtles.  相似文献   

Dynamic analysis of a vertical plate exposed to breaking wave impact     

M. Salih Kirkgoz  A. Kamil Tanrikulu  Cengiz Dündar 《Ocean Engineering》2004,31(13):2308-1635

From the experimental studies in recent years, it has become known that when a wave breaks directly on a vertical faced coastal structure, high magnitude impact pressures are produced. The theoretical and experimental studies show that the dynamic response of such structures under wave impact loading is closely dependent on the magnitude and duration of the load history. The dynamic analysis and design of a coastal structure can be succeeded provided the design load history for the wave impact is available. Since these types of data are very scarce, it is much more convenient to follow a method which is based on static analysis for the dynamic design procedure. Therefore, to facilitate the dynamic design of a vertical plate that is exposed to breaking wave impact, a multiplication factor called “dynamic magnification factor” is herein presented which is defined as the ratio of the maximum value of the dynamic response to that found by static analysis. The computational results of the present study show that the dynamic magnification factor is a useful ratio to transfer the results of static analysis to the dynamic design of a coastal plate for the maximum impact pressure conditions of p_max/γH₀≤18.  相似文献   

船舶受冲击力作用时的水动力试验研究     

王建平  王文富等 《海洋工程》2003,21(1):87-89,93

根据冲量相似的要求进行船舶在冲击作用下的模型试验，并将模型试验结果与理论计算及实际试验进行了对比和分析。  相似文献   

水下运载器外挂负载的系统测试方案及仿真     

杨洪刚  连琏  葛彤 《海洋工程》2006,24(1):60-67

研究水下运载器外挂负载的测试问题,根据负载功能,建立了负载的系统模型。考虑到系统可测性,模型中增设一些辅助元件和电路,测试计算机通过与负载的自动驾驶计算机通讯,由自动驾驶计算机施加激励和采集响应,完成测试。最后,对测试方案进行了仿真试验,并分析了仿真结果。  相似文献   

压力传感器的自动标定技术     

王莉娜  赵先龙  阮锐  严晓明 《海洋测绘》2007,27(4):78-80

针对压力测量设备生产和维护过程中,对关键部件压力传感器标定处于手工操作状态、效率低、操作人员不易掌控、标定结果处置复杂的现状,开发了针对压力传感器的自动标定技术。该技术将计算机控制、智能化、曲线拟合和误差分析引入到压力传感器的标定过程中,大幅度提高了标定的效率和可靠性。经此技术标定过的压力探头,在使用中具有互换性,减轻了数据后处理工作的难度。  相似文献   

海洋平台沉垫的波浪载荷试验研究   总被引：2，自引：0，他引：2  

姚美旺  张承懿  缪国平  季春群 《海洋工程》1997,(4)

本文通过对海洋平台沉垫的波浪载荷试验研究分析，着重研究了在规则波中平台沉垫总体波浪载荷和局部水动压力分布的情况，定性地考察了非线性影响、浅水影响的重要性，为今后波浪理论中粘性的引入，进而考虑粘性与波浪运动的非线性相互干扰提供实测依据  相似文献   

中国对虾育苗池和养成池微型污着生物群落的研究     

胡超群  谭智源 《海洋与湖沼》1996,27(5):481-486

于１９９２年４－１０月在山东省青岛市黄岛前湾育苗场和胶南市红石崖镇邵家村养殖场，采用载玻片挂片和对中国对虾现场取样的方法，研究中国对虾育苗池和养成池载玻片挂 表面和对体表微型污着生物群落的组成和发展。  相似文献   

Prediction of impact pressure induced by breaking waves on vertical cylinders in random seas     

Michel K. Ochi  Chen-Han Tsai 《Applied Ocean Research》1984,6(3):157-165

This paper presents a method to statistically predict the magnitude of impact pressure (including extreme values) produced by deep water waves breaking on a circular cylinder representing a column of an ocean structure. Breaking waves defined here are not those whose tops are blown off by the wind but those whose breaking is associated with steepness. The probability density function of wave period associated with breaking waves is derived for a specified wave spectrum, and then converted to the probability density function of impact pressure. Impacts caused by two different breaking conditions are considered; one is the impact associated with waves breaking in close proximity to the column, the other is an impact caused by waves approaching the column after they have broken. As an example of the application of the present method, numerical computations are carried out for a wave spectrum obtained from measured data in the North Atlantic.  相似文献   

中国海岸湿地退化压力因素的综合分析   总被引：39，自引：1，他引：39       下载免费PDF全文

谷东起  赵晓涛  夏东兴 《海洋学报》2003,25(1):78-85

对我国海岸湿地类型、特点和分布进行了论述.通过分析指出围垦、城市与港口开发、污染、海岸侵蚀、油气资源开发、生物资源过度利用和海平面上升等环境压力因素是造成湿地退化的主要原因.综合矩阵因子分析表明,不同的海岸湿地类型所承受的环境压力和所遭受的环境退化程度是不同的,其中三角洲、海岸潟湖、砂质海岸、珊瑚礁、淤泥质海岸、滨岸沼泽和红树林等湿地类型遭受的环境压力最大,环境退化也最严重;指出了人为因素是造成海岸湿地环境退化的主要原因.  相似文献