土壤加固技术及其发展

提出并区分了土壤加固、土壤稳定和土壤固化的概念,得出土壤固化和土壤稳定既有区别,又有交叉重叠的部分,但它们都同属于土壤加固的范畴。综述了目前主要的土壤加固技术的方法、原理及其发展,包括机械力加固、热处理加固、化学加固、加筋加固和注浆加固。其中,化学加固中的土壤固化剂技术在近几十年发展迅速,有大量研究成果和工程应用;阐述了钙基类与非钙基类固化剂的种类、特点和加固机理,分析了新型非钙基类固化剂应用现状及其原因;介绍了生物注浆加固技术的方法和原理。     

软岩隧道施工技术探讨

本文通过西南某山区铁路斜坡软土地段的软岩隧道施工所揭示的工程地质问题,浅述了对炭质页岩、泥灰岩岩性的初步认识和采取的施工对策,重点介绍了软岩隧道浅埋洞口段施工技术,及富水软岩破碎段施工支护开裂变形,衬砌混凝土开裂的原因分析及处理技术。     

超高索塔锚固区用高性能纤维混凝土泵送性能研究

纤维混凝土因可泵性差很少用于索塔锚固区。本试验主要研究纤维混凝土的泵送问题。基于多重复合技术,经过试验优化出的高性能纤维混凝土,搅拌出机后纤维分散均匀,拌合物有良好的保水性和粘聚性,1 h内泵送性能优良。通过120 m和216 m高塔可泵性试验结果来看,所配制的纤维混凝土能够泵送到300 m高度。     

指纹技术在确定交通事故驾车人中的应用

针对交通事故调查中驾车人确定的难点,提出将指纹技术应用于其中,以有力地支持事故调查的顺利完成;并对指纹技术的理论原理、操作方法、应用程序作了系统的探讨。     

混凝土路面真空处理技术

对混凝土路面中真空混凝土处理技术原理、特点进行了论述。     

北京地铁和平西桥站-北土城东路站区间渡线区隧道暗挖施工技术

文章主要介绍了北京地铁五号线和-北区间渡线区暗挖隧道断面转换施工技术,其经验可为今后类似城市地铁工程施工提供借鉴。     

On the existence of stationary states in general road networks

Our daily driving experience and empirical observations suggest that traffic patterns in a road network are relatively stationary during peak periods. In numerous transportation network studies, there has been an implicit conjecture that stationary states exist in a network when origin demands, route choice proportions, and destination supplies are constant. In this study, we first rigorously formulate the conjecture within the framework of a network kinematic wave theory with an invariant junction model. After defining stationary states, we derive a system of algebraic equations in 3-tuples of stationary link flow-rates, demands, and supplies. We then introduce a new definition of junction critical demand levels based on effective demands and supplies. With a map in critical demand levels, we show that its fixed points and, therefore, stationary states exist with the help of Brouwer’s fixed point theorem. For two simple road networks, we show that the map is well-defined and can be used to solve stationary states with a brute-force method. Finally we summarize the study and present some future extensions and applications.     

Cost effective future derailment mitigation techniques for rail freight traffic management in Europe

Safe and reliable traffic management is vital for uninterrupted and successful operation of the European rail network, where mixed traffic (i.e. freight and passenger) services are run. Although rail freight derailment is infrequent, its consequences can be severe and may result in different forms of costs, including infrastructure; rolling stock; traffic disruptions; injuries and fatalities. The objective of this research paper is to conduct a cost benefit analysis (CBA) to identify cost effective mitigation techniques for efficient rail freight traffic management in Europe, by 2050. Reviewing previous derailments and studies, eight sets of derailment causes are analysed and, for each of them, sets of mitigation techniques are aimed at for their alleviation. The study finds that the highest cumulative costs of derailment are associated with ‘wheel failure’, while the lowest cumulative cost is identified for ‘excessive track width’. Regarding mitigation techniques, the lowest cumulative benefits are demonstrated for ‘track height’ interventions, whereas ‘wheel failure’ alleviation demonstrates the highest benefits, in value terms (all by 2050). In most cases, the benefit to cost ratio did not exceed 2.6; in two cases (‘track height’ and ‘rail failures’) the ratio remained below 1 – a negative outcome where cost is higher than benefit. The study suggests that the most cost-efficient interventions are those applied to ‘hot axle box and axle rupture’ and ‘spring and suspension failure’.     

高架轨道交通减振措施研究

介绍了高架轨道交通产生的振动对周围环境的影响和环境振动控制标准,提出了高架轨道交通在规划设计阶段的减振技术路线,从轨道结构和桥梁结构2个方面阐述了减振技术措施。通过室内试验方法,验证了梯形轨枕轨道系统具有良好的减振性能。     

小水线面双体船纵向运动稳定性的简化判据及分析

本文根据劳斯判据分析了小水线面双体船（SWATH）静水纵向运动方程的稳定性，给出了适合于工程应用的纵向运动稳定性简化判据和临界巡航速度的计算方法。通过对三艘SWATH的实例计算，讨论了船形以及鳍的尺度、纵向位置和组合形式的变化对纵向运动稳定性的影响，提出了一种较完善的提高SWATH纵向运动稳定性的途径。