浅谈资源节约型高速公路路基合理高度的控制因素

首先介绍了公路低路基可行性的相关研究,阐述高速公路路基合理高度确定的传统方法,分析了低路基优缺点与特点,据此提出了低路基合理高度的控制因素,以实现资源节约型的设计理念。     

岩溶对隧道工程的影响及设计建议

介绍了岩溶的类型及对隧道工程的影响和危害,针对这些问题,提出了线位避让、岩溶水处理、合理选择隧道衬砌结构、坑道形式等设计建议及安全施工措施。     

谈创新工艺对公路建设的贡献

随着新工艺的推广和使用,公路施工中以往遇到的很多难题迎刃而解。文章介绍了两种公路施工新工艺,阐述了其优点及控制要点,在降低施工成本的同时缩短了施工工期。     

基于ANSYS/LS-DYNA的客车正面碰撞仿真分析研究

以某型大客车为例,基于ANSYS/LS-DYNA碰撞仿真软件,探讨碰撞仿真建模中的一些技术要点,建立大客车车身结构正面碰撞仿真有限元模型,并进行初始速度为30km/h的正面碰撞仿真研究。     

海上高频电子邮件技术

海上高频电子邮件技术[1]是海上高频数字通信技术的重要部分,使用PACTOR-Ⅲ协议和现有海上中/高频无线电设备,经由全球链路网( GLN)与陆上用户进行通信.海上高频数字通信技术主要包括PACTOR-Ⅲ协议和T总线协议.对海上高频数字通信的带宽和传输速率、调制、编码和码率、振幅因数与发射机输出功率、数据包的结构、控制信号、信号特征等技术问题的分析,对海上高频段新通信技术的引进有非常重要的价值.     

Research on the dynamic buckling of a typical deck grillage structure subjected to in-plane impact Load

The dynamic buckling of the main deck grillage would result in the total collapse of the ship hull subjected to a far-filed underwater explosion. This dynamic buckling is mainly due to the dynamic moment of the ship hull when the ship hull experiences a sudden movement under impact load from the explosion. In order to investigate the ultimate strength of a typical deck grillage under quasi-static and dynamic in-plane compressive load, a structure model, in which the real constrained condition of the deck grillage was taken into consideration, was designed and manufactured. The quasi-static ultimate strength and damage mode of the deck grillage under in-plane compressive load was experimentally investigated. The Finite Element Method (FEM) was employed to predict the ultimate strength of the deck grillage subjected to quasi-static in-plane compressive load, and was validated by comparing the results from experimental tests and numerical simulations. In addition, the numerical simulations of dynamic buckling of the same model under in-plane impact load was performed, in which the influences of the load amplitude and the frequency of dynamic impact load, as well as the initial stress and deflection induced by wave load on the ultimate strength and failure mode were investigated. The results show that the dynamic buckling mode is quite different from the failure mode of the structure subjected to quasi-static in-plane compressive load. The displacements of deck edge in the vertical direction and the axial displacements are getting larger with the decrease of impact frequency. Besides, it is found that the dynamic buckling strength roughly linearly decreased with the increase of initial proportion of the static ultimate strength P₀. The conclusions drawn from the researches of this paper would help better designing of the ship structure under impact loads.     

橡胶沥青结合料性能影响因素分析

为了研究橡胶沥青结合料的性能,对橡胶沥青结合料的搅拌方式、搅拌温度、胶粉掺量、搅拌时间和老化性能等影响因素进行分析.研究结果表明:选择恰当的生产工艺,确保各影响因素在最佳状态,可显著提高橡胶沥青结合料的各项性能.     

广州市地面塌陷特征与防治对策初步研究

广州市地面塌陷频繁发生,近20年来呈波浪式上升趋势,分析和探讨地面塌陷形成类型、分布特征、诱发因素,并提出预防地面塌陷的措施与对策。     

惠兴高速公路K115段工程滑坡稳定性的外部影响因素分析

在对滑坡自然形态、变形破坏现象及滑坡变形特征的调查分析基础上,分析研究了各影响因素(包括内因和外因)对滑坡的地质作用机理,依据二维刚体极限平衡原理进行滑坡稳定性安全系数计算,开展各影响因素之间的相对敏感性分析。通过影响比例的数值分布规律分析,实现各外部影响因素影响程度等级化归类,为滑坡稳定分析、治理设计及施工提供有力的技术依据。     

External costs of electric vehicles

Electric vehicles (EV) are often considered a promising technology to decrease external costs of road transport. Therefore, main external cost components are estimated for EV and internal combustion engine vehicles (ICEV). These include costs of accidents, air pollution, climate change, noise, and congestion. All components are estimated over the product lifetime and, where appropriate, differentiated according to fuel type, vehicle size as well as emission location and time. The advantage of this differentiation is, however, compensated by high uncertainties of most cost estimates. Overall, the external costs of EV and ICEV do not differ significantly. Only for climate change, local air pollutants in congested inner-cities, and noise some advantageous effects can be observed for EV. The advantages depend strongly on the national electricity power plant portfolio and potentially also on the charging strategy. Controlled charging might allow for higher emission reductions than uncontrolled charging of EV.