大桩帽轨道梁不同支承条件的受力分析

通过ANSYS软件对轨道梁的弹性点支承、刚性点支承、分布弹性支承以及空间模型进行有限元模拟,得出不同模型下的连续梁内力以及支座反力,并对不同模型的计算结果进行比较分析。计算结果表明,弹性点支承与刚性点支承模型在计算宽支座梁支座负弯矩时与分布弹性支承模型及空间模型差异较大,在支座边缘处采用弹性点支承模型计算弯矩削峰的方法已不再适用,同时得到宽支座梁支座反力、剪力等分布规律,可供大桩帽连续梁设计参考。     

弹性支承连续梁结构设计方法的探讨

在港口码头设施中,轨道式起重机是最常用的装卸设备.这些在轨道上运动的机械设备荷载(轮压)非常大.如果轨道梁采用桩基支承,其结构应按弹性支承连续梁的力学模型进行结构计算,那么在桩基的轴向刚度系数(弹性支座的刚度)的取值、桩距的确定、梁截面的选择等弹性支承连续梁设计参数中弹性支座的刚度系数取值是关键所在.     

宽支座连续梁弯矩简化计算方法研究

高桩码头纵横梁正负弯矩的最大值是工程设计中的控制因素,文章在分布弹性支承连续梁模型的基础上,提出宽支座连续梁跨中和支座的正负弯矩最大值的简化计算公式。对于不同悬跨比的连续梁,通过ANSYS对不同的支座相对宽度和相对刚性系数进行有限元模拟,根据数值分析结果确定公式中的系数。对某一高桩码头工程纵梁,将简化公式和有限元的计算结果进行对比,两者误差小于5%,说明简化公式具有一定参考意义。     

基于不同支承模型的连续梁内力分析

高桩码头结构纵梁的计算是很重要的一项内容,纵梁一般为连续梁结构,连续梁的支承方式可以假定为不同的计算模型。本文分别按刚性支承、弹性点支承、考虑支座宽度的弹性支承对连续梁内力进行计算,并对计算结果做了比较分析。     

梁系平面刚度偏心分布高桩平台结构地震响应

基于工程实例,采用反应谱方法、时程分析法对梁系平面刚度偏心分布高桩平台结构地震响应规律进行分析研究。结果发现：横向地震作用下,反应谱法和人工波时程分析法计算结果较为接近,天然波时程分析法结果则因选波呈现差异;桩基二维、三维模型计算结果较为接近,横梁二维、三维模型剪力峰值计算结果接近,弯矩峰值结果差异大。纵向地震作用下,三维反应谱法和人工波时程分析法计算结果接近。不同计算模式对比表明三维反应谱法适应性较好。抗震设防烈度大于7度时,该类型平台结构桩基不宜选用PHC桩。对梁-板连接刚性系数λ进行参数分析表明：λ变化对横梁、纵梁内力的影响大于对桩基的影响,对纵横梁弯矩的影响大于对剪力的影响,且纵向地震作用下影响程度大于横向地震。说明板、梁之间的约束状态改变了结构的刚度分配情况,进而对结构的地震效应产生规律性影响。     

考虑转动约束的宽支座连续梁计算方法

针对现有JTS 167-1—2018《码头结构设计规范》大桩帽轨道梁宽支座计算方法的不足，提出带转动约束的宽支座连续梁计算模型，推导了宽支座转动刚性系数计算公式；运用Fortran语言对带转动约束的宽支座连续梁模型编写有限元程序，并通过ANSYS软件建立纵向排架的空间有限元模型作为对比分析，得出不同计算模型下的连续梁内力。计算结果表明，在均布荷载情况下，忽略支座转动约束会对计算宽支座连续梁最大正弯矩带来较大的误差，考虑转动约束的宽支座连续梁模型计算所得最大正弯矩与空间模型比较接近；而规范方法与本文提出的计算模型所得梁最大负弯矩与空间模型差别均较大，对其原因进行分析并提出改进建议，以供类似码头结构设计参考。     

桩基支撑轨道梁结构设计影响因素分析

桩基支撑轨道梁是具有弹性支座的连续梁结构，计算发现并非轨道梁尺寸越大，结构就越安全。设计参数相近时不同项目采用的轨道梁尺寸及桩基布置有较大差异。对此，从桩基竖向抗压刚度、桩距、轨道梁刚度3个方面进行轨道梁内力分析。结果表明当荷载和桩基布置确定时，存在一个最优梁高，使得轨道梁钢筋用量最小。进一步分析可知，当荷载和梁长度一定时，轨道梁的内力分布与桩和梁的相对刚度有关。在设计桩基支撑轨道梁时需试算出最优相对刚度，可使内力分布更合理且节省工程造价。同时，基于工程实例给出不同桩距下的最优相对刚度区间，可为类似项目的设计提供参考。     

高桩码头轴向刚性系数对弯矩的影响

为了研究轴向刚性系数对弯矩的影响,根据不同的轴向刚性系数对应的弯矩不同,引入无量纲支座相对系数α,系统地研究不同荷载分布形式下对应的α对弯矩的影响。通过分析得到：轴向刚性系数主要影响0～1.5边跨范围内的弯矩,悬臂越大影响越小;弯矩与α13、α23存在线性关系;通过线性拟合,找到不同的荷载分布形式下α的变化对弯矩的影响,进而让设计及研究者更加理解轴向刚性系数与弯矩之间的关系。     

预应力混凝土曲线梁桥几个问题研究

曲线梁桥是弯扭耦合作用下的空间受力结构,现行桥梁规范所包括的内容滞后于桥梁的发展,平面分析的方法已不适用。文中对曲线梁桥的弯扭耦合效应、内外梁体受力不均以及恒载作用下结构产生较大的转矩等受力特点进行了分析。分析结果表明：曲线梁桥中间支承方式的设定不能改变支座的反力,外侧腹板弯矩内力均大于内侧腹板的弯矩内力,曲线半径越小,变化幅度越大。     

高桩码头大跨度非完全排架结构承载特性

针对高桩码头大跨度非完全排架结构承载特性问题,采用ANSYS建立三维模型,研究不同工况对其结构承载特性的影响。结果表明:门机荷载对该新型结构的桩基内力影响较大,均布荷载主要影响中纵梁和横梁内力,而门机荷载则主要影响轨道梁内力;此外,中纵梁下方的桩基轴力明显较轨道梁下方桩基轴力大,而桩身弯矩则由码头前沿向陆侧逐渐增加;相邻排架间轨道梁下的双直桩对轨道梁的内力起到应力重分配的作用,使各轨道梁受力更加均匀,有利于各跨轨道梁协同作用、共同发挥承载作用。     

Errata

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.     

Journal of Marine Science and Application 2014 Sum. Contents

正~~     

第34届海洋、离岸及极地工程国际会议(英文)

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;     

联合作战计划和执行系统

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。     

Eastbound or westbound ?

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）.     

Recent progress on wave induced loading measurements in warships

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.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

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.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。