既有立交改扩建工程方案设计探讨

既有立交改扩建工程方案设计时,需综合考虑立交的新功能定位、交通量适应性、既有构造物利用、对现有道路交通的影响、立交工程造价等因素。结合相关经验,根据立交改扩建的背景原因,提出不同情况下既有立交改扩建工程方案设计思路,具有一定的理论和实际意义。     

高陡边坡生态防护的研究与工程应用

在我国西南部地区高速公路建设过程中,高陡边坡的数量占了很大的比例,一般的生态防护护坡技术达不到理想的护坡效果。植生板生态植被护坡技术能够有效地弥补其他生态防护的不足,达到合理的生态防护效果。     

Scheduled paratransit transport systems

In this paper we focus on ways to provide individualized services to people with mobility challenges using existing modes of public transport. We study the design of an interesting case, in which a bus operating in a public transport route may diverge from its nominal path to pick-up passengers with limited mobility and drop them off at their destination. We have modeled the design problem by a mixed integer-linear program, and we developed an exact Branch and Price approach to solve it to optimality. The proposed approach includes a labeling algorithm in which we introduced appropriate dominance rules, which do not compromise optimality. We have compared the efficiency of our approach with that of related algorithms from the literature. Furthermore, we have used the proposed approach to study key aspects of the system design problem, such as the effect of various constraints on the service level, and the tuning of the system’s parameters to address different transport environments.     

Evolution of latent modal captivity and mode choice patterns for commuting trips: A longitudinal analysis using repeated cross-sectional datasets

This paper presents an investigation of the temporal evolution of commuting mode choice preference structures. It contributes to two specific modelling issues: latent modal captivity and working with multiple repeated crossectional datasets. In this paper latent modal captivity refers to captive reliance on a specific mode rather than all feasible modes. Three household travel survey datasets collected in the Greater Toronto and Hamilton Area (GTHA) over a ten-year time period are used for empirical modelling. Datasets collected in different years are pooled and separate year-specific scale parameters and coefficients of key variables are estimated for different years. The empirical model clearly explains that there have been significant changes in latent modal captivity and the mode choice preference structures for commuting in the GTHA. Changes have occurred in the unexplained component of latent captivities, in transportation cost perceptions, and in the scales of commuting mode choice preferences. The empirical model also demonstrates that pooling multiple repeated cross-sectional datasets is an efficient way of capturing behavioural changes over time. Application of the proposed mode choice model for practical policy analysis and forecasting will ensure accurate forecasting and an enhanced understanding of policy impacts.     

旧路新增互通式立交方案探讨

中山市二环快速路是在既有道路基础上提升改造的城市环线。其北段与东段（既有S111）相交于中山港大桥，在本次改造时，在该处设置群乐互通式立交。详细分析中山港大桥新旧桥的结构型式及病害情况，明确新增群乐互通式立交设计的边界条件及影响因素，并深入探讨群乐互通式立交方案。     

基于PFV策略的连续型元胞自动机交通流模型

科学合理的微观交通流仿真模型是研究交通控制手段有效性的关键.本文结合一种考虑驾驶员视野内前后多车影响的跟驰策略，建立了连续型元胞自动机交通流模型.仿真实验表明，仿真数据与实测数据有较好的拟合性，仿真得到的 K-Q、K-V和 Q-V图能较好地反映实际道路交通流的失稳现象，所建立的模型具有适应不同场景的兼容性与灵活性，能够作为研究我国实际道路交通流问题的仿真工具.     

蒲庙大桥吊杆更换施工技术

文章以南宁蒲庙大桥的维修加固工程为背景,阐述了拱桥吊杆更换的原则、关键技术、施工特点和吊杆的选取情况,介绍了吊杆更换的施工工艺流程,并从施工准备、体系转换、拆除旧吊杆、安装新吊杆、吊杆防护等方面探讨了拱桥吊杆更换的施工技术要点。实践证明,该吊杆更换技术是安全可行的。     

浅析建筑废弃物在虹桥综合交通枢纽的应用

该文对虹桥综合交通枢纽市政配套工程固废利用试验段的实施进行了总结,提出了建筑渣土用于路基处理是可行的,但使用HEC固结建筑渣土时应加强对施工工艺的改进,使用水泥固结建筑渣土时应就近设置破碎拌和厂;同时,由于HEC/水泥固结建筑渣土的后期开裂性能未有进入研究,建议在道路基层中应谨慎使用。     

桥梁上部结构水损害病害分析

针对目前我国桥梁上部结构水损害比较普遍这一现象，以历年来对河北省运营的多条高速桥梁定期检查资料为基础，对桥梁上部结构水损害进行较为详细的分析，对于优化桥面防水设计，改善桥面防水、排水系统具有参考价值。     

基于孔隙结构的土体未冻水含量滞回效应研究

冻结特征曲线（SFCC）是描述负温与土体内部未冻水含量之间的关系曲线，是非饱和冻土研究的重要基础。冻融循环是冻土研究的关键因素。以粉土和黏土为试验对象，采用低场核磁共振（NMR）技术，测得了土体在冻融循环作用下的冻结特征曲线和孔隙结构分布图，研究土体在冻融循环作用下冻结特征曲线的变化。试验结果表明：随着循环次数的增加，土体孔隙分布发生了变化，进而导致冻结特征曲线滞回圈和特征温度点的变化，冻结特征曲线变化的本质是孔隙结构的变化；从微观结构出发得到了基于孔隙结构的SFCC表达式，指出融化过程的冻结特征曲线是主冻结特征曲线；结合试验数据的对比分析，模型有效展示了多次冻融循环下土体冻结特征曲线的滞回效应，适用于多次循环下的非饱和冻土。