风沙地区铁路选线勘测中应关注的几个问题

风沙地区铁路工程的选线和勘测是铁路修建前期工作中很重要的阶段。结合乌锡线的勘测及施工经历，通过实例总结了风沙地区铁路前期选线中，地质勘察的一般方法和应引起重视的几个问题，使勘测工作能为铁路工程的设计提供可靠资料。     

三峡库区港口边坡生态防护技术研究

针对三峡库区复杂工程地质与水位条件下的港口高边坡稳定性与生态防护技术进行了深入研究,在国内外库区岸坡防护技术的基础上进行了优化比选,提出了采用香根草护面加筋边坡这一新型结构体系对三峡库岸边坡进行防护,并采用有限元仿真模拟计算与工程试验相结合的方法进行了论证。实践表明,该防护技术满足三峡库岸边坡防护的安全经济、环保性要求,是一种新型有效的库区港口边坡生态防护技术。     

对船舶污染损害侵权责任及索赔主体问题的探讨

船舶污染事故是造成海洋环境污染损害的主要原因之一,建立完善的船舶污染损害索赔机制,保证受损方获得及时的赔偿,是恢复海洋环境、维护受害者利益所必须的。文中从民法的基本原理出发,对国家海域所有权、海域使用权等进行了论述,并按照民事侵权责任的承担原则,对索赔权利主体的确定等问题进行了探讨。     

山区公路库区浸水路段加筋土高挡墙的应用

以景宁县库区浸水路段为例，对加筋土高档墙的应用进行深入研究分析，有利于此类加固技术的推广应用。     

Simulation of dynamic interaction between train and railway turnout

Dynamic train–track interaction is more complex in railway turnouts (switches and crossings) than that in ordinary tangent or curved tracks. Multiple contacts between wheel and rail are common, and severe impact loads with broad frequency contents are induced, when nominal wheel–rail contact conditions are disturbed because of the continuous variation in rail profiles and the discontinuities in the crossing panel. The absence of transition curves at the entry and exit of the turnout, and the cant deficiency, leads to large wheel–rail contact forces and passenger discomfort when the train is switching into the turnout track. Two alternative multibody system (MBS) models of dynamic interaction between train and a standard turnout design are developed. The first model is derived using a commercial MBS software. The second model is based on a multibody dynamics formulation, which may account for the structural flexibility of train and track components (based on finite element models and coordinate reduction methods). The variation in rail profile is accounted for by sampling the cross-section of each rail at several positions along the turnout. Contact between the back of the wheel flange and the check rail, when the wheelset is steered through the crossing, is considered. Good agreement in results from the two models is observed when the track model is taken as rigid.     

Mathematical modelling of train–turnout interaction

The paper proposes a mathematical model of train–turnout interaction in the mid-frequency range (0–500 Hz). The model accounts for the effects of rail profile variation along the track and of local variation of track flexibility. The proposed approach is able to represent the condition of one wheel being simultaneously in contact with more than one rail, allowing the accurate prediction of the effect of wheels being transferred from one rail to another when passing over the switch toe and the crossing nose. Comprehensive results of train–turnout interaction during the negotiation of the main and the branch lines are presented, including the effect of wear of wheel/rail profiles and presence of track misalignment. In the final part of the paper, comparisons are performed between the results of numerical simulations and line measurements performed on two different turnouts for urban railway lines, showing a good agreement between experimental and numerical results.     

双层采空区隧道开挖围岩稳定性数值模拟

隧道下穿煤层采空区开挖不可避免地会对周围地层产生扰动,"活化"既有采空区,影响隧道及采空区周围地层的稳定性。由于双层采空区的特殊性,采空区与采空区之间也会产生一定的影响。利用FLAC3D软件,通过控制变量法建立双层采空区隧道模型进行计算,考虑采空区高度及采空区之间间距的影响,对隧道开挖过程中围岩形变及位移、围岩应力及围岩塑性区的开展情况进行分析。得出双层采空区存在时,当采空区之间间距大于20倍煤层采高时,双层采空区可按单层采空区进行处理。     

一种实用路由器的设计研究

基于一个已完成的部级科研项目的研究，提出了一种实用的可用于互联中小型局域网的通用路由器的总体设计方案。说明了路由器的功能需求，着重从软硬件设计上讨论了其实现过程。     

51800DWT冰区加强型成品油轮船体结构设计

51800DWT冰区加强型化学品／成品油轮是广船国际自行开发设计的、具有世界先进水平的北极冰区航线成品油／化学品船。该船可满足全球造船业所公认的高等级规范“瑞典-芬兰冰级1Asuper”。本文结合冰区加强结构设计介绍该船的船体结构设计特点。     

基于知识工程的道岔零部件设计

利用CATIA软件的知识工程进行道岔零部件的系列化设计,建立了企业的三维模型库,显著减少设计人员的重复工作量,提高设计的效率和质量。