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1.
室内试验表明,多哈新港码头灰岩回填料存在较高含量的坡缕石矿物,具有一定的膨胀性和分散性,且不能同时满足细粒含量小于15%、液限和塑性指数分别低于65%和35的设计要求,在技术规格书中属于不合格回填料。为合理利用这部分港池开挖料、减少弃土含量,重新提出回填料碾压处理后孔隙率应小于10%、且浸水饱和后体积变化量不应超过回填厚度1%的要求。通过对回填料试样进行颗分和液塑限试验、土的颗粒密度试验、室内击实试验、X射线衍射试验、膨胀率室内试验,建立了高坡缕石灰岩回填料膨胀性与细粒含量关系式,得出细粒含量小于45%的回填料能够满足工程使用的结论,并由室外大型浸水模型试验进行验证。但当细颗粒含量在20%~40%回填料使用时,还应考虑黏土矿物分散性影响。 相似文献
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为了保证项目工期和控制吹填砂细颗粒含量小于20%,在开工前及施工过程中采用海上标准贯入实验SPT,并通过N值和室内筛分试验结果,对地层的土质类别及细颗粒含量等情况进行研究。同时,通过现场挖泥船实际吹填效率分析,得到实际疏浚吹填中SPT标准贯击数与不同类型挖泥船的挖掘能力的关系:当N值大于30时,现场7025型绞吸船较难开挖,需引入大型绞吸船或耙吸船开挖。相同土质耙吸船吹填料的细颗粒含量远远低于绞吸船。因此,根据SPT钻孔资料合理安排施工船舶和施工工艺,对项目顺利实施、节约成本具有重大意义。 相似文献
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《中国水运》2017,(9)
地下水封洞库截面形状对围岩稳定性及支护结构安全性具有重要影响。以某地下水封洞库马蹄形截面为基础,设计三种不同规格的洞室截面(18m×26m,20m×24m,22m×26m),利用FLAC3D数值分析平台,开展洞室截面形状优化研究。数值模拟结果表明:仅有18m×26m截面在边墙部位出现拉应力集中区,最大为0.13MPa,20m×24m截面的最大压应力为16.8MPa小于22m×26m截面的18.2MPa;围岩位移量中,20m×24m截面最小,为3.72mm;围岩塑性区基本呈环形分布,其厚度约为4-5m,且20m×24m截面产生的塑性区体积最小。分析认为,20m×24m截面最优的原因在于该区以水平地应力为主。研究结论从而为其它地下水封洞库截面形状设计提供参考。 相似文献
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《中国水运》2019,(7)
为分析固化疏浚淤泥(DS)-磷石膏(PG)混合土自生体积变形的工程适用性,研究其体积稳定性。制备了直径50mm、高300mm的试件,利用位移传感器测量试件线性变形,分析了不同养护龄期下,疏浚淤泥初始含水率、疏浚淤泥与磷石膏基质土配比(DS:PG)、固化剂掺量等因素对固化混合土自生体积稳定性的影响。研究表明:固化混合土膨胀与收缩共生,体积变形表现为膨胀性;膨胀主要发生在养护早期(前28d),后期体积变化不大;固化混合土膨胀率随着固化剂掺量的增大而增大,随着疏浚淤泥初始含水率、基质土配比(DS:PG)的增大而减小;综合评判固化混合土属于弱膨胀土,且膨胀率可调控,具有较好的体积稳定性,可以作为填料。 相似文献
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航道开挖后容易出现回淤,回淤量研究对航道后期的维护尤为重要。以高栏港进港航道泥沙回淤为研究对象,结合黄茅海海域的海床历史演变情况,分析高栏港区航道泥沙来源,研究航道附近泥沙冲淤变化特征。研究结果表明:高栏港所在的十字水域海床近年来处于淤积状态,1977—1989年,平均淤积强度为3. 42 cm/a; 1989—2003年,淤积速率减缓,约为0. 86 cm/a。高栏港区航道年淤积量由常年淤积和台风骤淤两部分组成,航道每年发生明显骤淤1~2次,骤淤量一般为常年淤积量的30%~50%,骤淤引起的平均淤积厚度为0. 32~0. 60 m,骤淤量的大小和分布与台风路径及强度有关。研究成果对于航道维护时间及频次确定具有参考作用。 相似文献
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针对如何提高混凝土灌注桩承载力的问题,基于混凝土补偿收缩理论,在混凝土灌注桩中加入适量的HCSA高性能膨胀剂。通过测定不同掺量HCSA膨胀剂对于水泥胶砂试件膨胀变形的影响,测定不同掺量HCSA膨胀剂对于混凝土强度和体积变形的影响,并将其应用于工程实践中。结果表明,HCSA膨胀剂具有更快的膨胀速率及更大的膨胀能力,HCSA膨胀剂在15%掺量时,灌注桩承载力提高了34.3%,沉降量仅为普通混凝土桩的36%~44%,桩身质量得到了提高。 相似文献
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以引江济淮膨胀土边坡为研究对象,以温度场模拟湿度场、建立温度场与湿度场等价转化条件,进而采用数值模拟方法研究膨胀土边坡吸湿膨胀变形机理、抗滑桩对膨胀土边坡的加固机理及抗滑桩在边坡上的最佳布置位置。取现场原状中等膨胀土并分别制成初始含水率15%(初始干密度1.45 g/cm~3)、初始含水率17.5%(初始干密度1.53 g/cm~3)、初始含水率20%(初始干密度1.60 g/cm~3)的三种土样,然后进行室内试验并获得土体普通物理力学指标参数及热力学指标参数。利用这些参数,进行不同土质条件下膨胀土边坡吸湿膨胀变形的数值模拟及有抗滑桩条件下膨胀土边坡吸湿膨胀变形模拟。计算结果表明,不同土质条件下随着降雨时间增长边坡土体变形均在增长,但膨胀土初始含水率大、干密度大,边坡土体变形较小;抗滑桩能够大大降低膨胀土边坡滑坡风险,抗滑桩布置在边坡中部时,膨胀土边坡的变形最小。 相似文献
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《船舶与海洋工程学报》2014,(2)
正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors. 相似文献
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《船舶与海洋工程学报》2014,(4)
正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support; 相似文献
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《船舶与海洋工程学报》2014,(1):126-126
正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field. 相似文献
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联合作战计划和执行系统 总被引:2,自引:1,他引:1
全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划:时间不限的精密预案计划生成作战计划、方案计划或职能计划;时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础,加速应付危机的能力。 相似文献
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Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form. 相似文献
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《船舶与海洋工程学报》2014,(1)
正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014. 相似文献
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《船舶与海洋工程学报》2014,(2)
正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas. 相似文献
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In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama?
The answer is China South Port Group (Hong Kong, Shenzhen and Guangzhou). 相似文献
The answer is China South Port Group (Hong Kong, Shenzhen and Guangzhou). 相似文献
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Gunnar Alexandersson Staffan Hultén Frode Longva 《Research in Transportation Economics》2010,29(1):212-218
Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues. 相似文献