110m长管幕在浅埋暗挖隧道中的应用研究

结合厦门高崎互通连接线下穿鹰厦铁路右线隧道,对110 m长管幕的施工技术和应用效果进行研究.通过采用先进的导向仪器和定向钻进技术,有效地控制了管幕的施工精度;采用挤扩法扩孔和"前拉后夯"工艺法施作管幕,减小了管幕施工对周边环境的影响.现场监测结果表明,管幕施工所引起的地表沉降较小,在隧道开挖过程中,管幕所起的支护作用非常明显,没有出现迅速沉陷、塌方等工程事故.但是由于地层本身非常松软,二次衬砌混凝土也未能及时跟上,在火车的动荷载和隧道开挖双重作用下地表测点最大累计沉降达到了90 mm.     

月相种种

月亮总是缺了又圆,圆了又缺.月亮的这种形状盈亏变化产生了种种月相(月亮形状称月相).种种月相则是月球、地球和太阳三者位置变化引起的.     

基于综合抢修性能的舰艇系统评估模型研究

综合抢修性能是衡量舰艇系统设计方案的重要指标之一。然而,影响系统综合抢修性能设计的因素较多,并且各因素之间相互关联,所以尚未有精确的方法来对系统综合抢修性能进行评估。基于此,文章采用层次分析法,对舰艇系统的综合抢修性能进行了评估,并对此算法的可行性进行了举例说明。     

Simulation of unsteady free-surface flow around a ship hull using a fully coupled multi-phase flow method

An accurate, efficient algorithm for solving free surface flows around ship hulls is described. Accuracy is achieved using a compressive advection discretization which maintains a sharp free surface interface representation without relying on a small time step. Efficiency is obtained using a solution algorithm which implicitly couples velocity, pressure, and volume fractions. The algorithm has been implemented in a computational fluid dynamics code called CFX and is validated by means of a comparisonwith experimental data of benchmark cases in both steady and transient conditions.     

半船移位受力分析及运动仿真研究

通过ADAMS软件对运用垂直半串连造船法建造的半船移位到指定坞位的全过程进行仿真,优化运动轨迹。使用FLUENT、MAXSURF等软件系统建立半船实体受力分析模型,对半船移位过程中拖轮的牵引力和转矩随时间的变化进行计算,为实际移位提供了理论数据。     

纯电动乘用车驱动电机选配

文章旨在通过分析纯电动乘用车与传统内燃机汽车在动力系统方面的差别，在以经验公式进行计算的基础上，根据前者动力系统的特点，结合某一款纯电动乘用车的项目，初步提出了纯电动汽车动力系统匹配的基本要求；通过分析现有驱动电机的特点，基于动力性、经济性、续航能力及噪声等因素的考虑，找到了一种能满足现阶段电动车开发的电机种类和参数的选配标准。     

集装箱箱号校验规则及其应用

集装箱是货物运输的辅助设备。采用集装箱运输, 有缩短货物装卸和周转时间、提高运输工具载运效率和箱体可重复利用等诸多优点。自上世纪60年代投入使用以来,集装箱在各国内外贸运输中被广泛使用,集装箱运输方式成为现代多式联运的发展方向。 1 集装箱箱号识别、校验机制的建立,推进了货运集装箱化     

化肥厂废渣在依勃公路路基中的应用

从煤灰渣的性能出发，提出了煤灰渣路堤的设计，施工方法，并以实验检测及依勃公路的实际应用证实，这一材料具有自重轻、强度高、压缩性小、渗透性好等工程特性。     

A comparative analysis of the European and North-American approaches to dealing with major oil spills

Background  

The question of what should be the right level of preparedness to react to a major oil spill (i.e. the EXXON VALDEZ spill, the ERIKA spill, and the PRESTIGE spill) is highly debated, especially in the aftermath of such spills. Little research, however, has been conducted with the aim to identify and compare governments’ best practices not only to fund preparedness measures but also to assess the countries’ ability to respond effectively to catastrophic oil spills. It is the author’s belief that important lessons can be learnt from a comparative analysis of countries’ best practices.     

Numerical analysis of crack under compression by 3D displacement discontinuity method

A 3D displacement discontinuity method is applied to solve the fracture mechanics problems of the mixed mode crack under compression. Friction between the surface of the closed crack is considered by establishing a simple and efficient iterative algorithm based on method of contact resistance mitigation. On the surfaces of the closed crack, the Mohr-coulomb rule is satisfied by iteration when the crack is in condition of sliding. The stress intensity factors are obtained using displacement fitting method. It is shown that the numerical results agree with the experimental results well and that friction plays an important role in resisting crack propagation.