高温条件下无缝线路换枕碴施工技术

换枕、碴本身就是对线路几何状态进行一种破坏性的施工作业,尤其是高速营业线上的高温季节,对跨区间无缝线路如何组织大型人工换Ⅱ型混凝土重枕和大机清筛更换Ⅰ级道碴,确保换枕、换碴后的线路不胀轨、施工人身安全得到保证和列车平稳正点运营是技术关键。文章就换枕、碴组织方案、工艺流程、质量控制、安全防范等作了详细介绍。     

Experimental Study on Excavation Characteristics of Rockmass by Triaxial Test

Applying MTS rock stiffness test machine, tests under triaxial condition were carried out for rockmass under loading and unloading. By measuring and analyzing such mechanical properties as stress, strain, elastic modulus, Poisson ratio and elastic wave velocity during the whole test process, the differences of mechanical characteristics under loading and unloading conditions were revealed, to provide some useful references for excavation.     

菲迪克条款及工程施工索赔

索赔管理是是工程项目管理最为重要的内容之一,灵活运用菲迪克条款保护企业的合法利益,关乎施工企业生存发展。本文结合菲迪克条款及作者的项目管理实践,介绍了工程施工索赔的必要性、必然性、合法动因和工程施工索赔的程序、技巧、注意事项等,对索赔管理工作人员的实际操作具有较强的针对性、指导性、实用性。     

高原型轨道车动力装置及传动方式的选型研究

为配合国家西部大开发 ,更好地为青藏铁路建设和未来青藏铁路运营、维修、抢险提供可靠、适用、便捷的轨道车辆设备。本文就解决轨道车在高海拔、低气压、缺氧、低气温、风沙大等特殊工作环境下其动力装置和传动方式选型的技术问题进行了研究、论证、分析和总结。     

大跨度先张法折线配筋预应力混凝土简支梁预制施工技术

24 m折线配筋先张法预应力混凝土简支梁是国内首次采用的新型结构,是青藏线采用的新技术之一,其技术含量高、施工工艺新、施工难度大、在国内尚属首次生产,根据工艺特点和施工要求,施工中预应力施工工艺、耐久性混凝土施工控制值得推广和研究。     

大跨度悬索桥施工猫道抗风稳定性分析

为了保证大跨度悬索桥施工猫道的抗风安全,通过风洞试验对悬索桥施工猫道进行了动力特性和抗风稳定性分析,结果表明,虽然没有采取设置抗风索的措施来提高猫道的抗风稳定性,但仍然具有良好的抗风稳定能力。     

浅谈铁路电气化工程项目的成本控制

加强工程项目的成本控制,是一个工程企业实现利润最大化、获得理想的经济效益的根本途径。本文分析了项目成本控制的主要环节,结合工程实践提出了项目成本的控制措施、方法及成本控制中应注意的几个问题。     

Bond Graphs for Vehicle Dynamics

For the purposes of analyzing the stability and control properties of aircraft, automobiles, and ships, it is convenient to idealize the vehicle as a rigid body and to use a body-centered coordinate frame. A six-port bond graph is first developed which represents the nonlinear dynamics of a rigid body in a coordinate system rotating with the body. It is then shown how the graph simplifies if only lateral or longitudinal dynamics are studied. Finally, bond graphs for the type of stability studies in which the assumption of small perturbations permits linearization are shown for elementary models of automobiles and aircraft.     

南京地铁暗挖隧道防水设计与施工技术

本文结合工程实际，就南京地铁暗挖隧道防水设计与施工技术进行了探讨，为今后类似工程提供参考。     

Power Requirements for Traversing Uneven Roadways

Vehicles which travel on uneven roadways or rough surfaces require power beyond that associated with air drag, rolling resistance or other sources of friction even though kinetic and potential energy may be conserved on the average. This is true because damped relative motions within the vehicle dissipate energy, and, even for nearly rigid vehicles, energy is lost at impact with the ground whenever the vehicle loses contact with the ground surface due to the finite downward acceleration of gravity.

Using elementary vehicle models, the nature and magnitude of the component of propulsive force associated with these energy loss mechanisms is estimated. In certain speed ranges, this force is found to vary dramatically with speed for several types of periodic roadway profiles studied. While the force due to unevennesss may be small compared to other forces for high-speed vehicles operating on smooth surfaces, it can be the major source of required power for off-road vehicles operating on very rough terrain.