大跨度混凝土斜拉桥拆除方案设计

上海泖港大桥老桥为(85+200-85)m双塔双索面预应力混凝土斜拉桥,采用塔梁固结、塔墩分离的结构体系.随着航道等级提升,该桥桥下净空无法满足通航需求,且原结构损伤较为严重,对其进行拆除.考虑紧邻新建主桥、老桥斜拉索损伤等不利影响,提出一套以“先上后下、逆序拆除”为原则的拆除方案,依次对桥面系、主梁、斜拉索、桥塔和下...     

Advances in consumer electric vehicle adoption research: A review and research agenda

In spite of the purported positive environmental consequences of electrifying the light duty vehicle fleet, the number of electric vehicles (EVs) in use is still insignificant. One reason for the modest adoption figures is that the mass acceptance of EVs to a large extent is reliant on consumers’ perception of EVs. This paper presents a comprehensive overview of the drivers for and barriers against consumer adoption of plug-in EVs, as well as an overview of the theoretical perspectives that have been utilized for understanding consumer intentions and adoption behavior towards EVs. In addition, we identify gaps and limitations in existing research and suggest areas in which future research would be able to contribute.     

Behavior of taxi customers in hailing vacant taxis: a nested logit model for policy analysis

This study models and examines the taxi customers' preferences for hailing vacant taxis on streets. A stated preference survey was conducted to randomly select and interview 1242 taxi customers at taxi stands and pedestrians on streets, who had experiences of taking taxis recently, about their choices under different given hypothetical scenarios. In total, 4968 observations were collected and used for developing the discrete choice models for the analysis. To account for the potential correlations among alternatives, two nested logit models are developed, calibrated, and compared with a standard multinomial logit model in the investigation. The results of likelihood ratio test demonstrate that one of the developed nested logit models is better than the standard multinomial logit model to describe the search behavior of taxi customers. The model results also show that the walking time to and the waiting time at the location for hailing taxis, the extra travel time to the destination because of local circulation for finding a way from the pickup location heading to a passenger's destination, as well as the taxi customers' perceptions for walking to and waiting at taxi stands were found as significant factors to influence their decisions. In addition, the results of market segmentation analysis illustrate the variations in taxi‐search strategies of taxi customers in different districts and regions. Some policy implications on introducing more taxi stands and improving the utilization rates of taxi stands are also discussed. We believe that the proposed models, findings, and discussion are useful for developing micro‐simulation models to evaluate the performance of road traffic networks with taxi services and developing simulation‐based optimization models to answer policy questions related to taxi services. Copyright © 2015 John Wiley & Sons, Ltd.     

永恒的人类之善--谈孔子和亚里士多德中庸思想的契合

孔子与亚里士多德处于公元前四五世纪中西轴心时代,相差一百六十多年,地域、国家、民族、时代、文化的差异并没有阻隔他们心灵、精神的暗相与会,用美国新人文主义杰出代表白璧德的话来说他们都见证了人类正常经验的核心。在中庸这一思想上,孔子和亚里士多德惊人一致地阐明了中庸是天人合一或与神合一的最高的善,是万事万物达到最佳状态的度,是人类最高的道德境界;人类行为若以善为内涵,体会完美的中庸之道,就能实现完满的幸福与和谐。     

硅藻土改性沥青胶浆高温性能评价

采用常规指标试验和不同温度下的高温动态剪切（DSR）试验,分析了硅藻土掺量对改性沥青高温性能的影响。试验结果表明：加入硅藻土后沥青胶浆的高温抗车辙能力明显提高,温度敏感性显著降低;随着硅藻土掺量增长,高温性能先提高后降低,合理掺量为11％-13％;常规指标不适合用于评价硅藻土改性沥青高温性能。     

大直径超长单桩竖向承载性能离心模型试验研究

通过单桩离心模型试验，获得了荷载与沉降关系曲线、桩身轴力分布，研究了大直径超长桩在竖向荷栽作用下，桩侧摩阻力、桩端阻力、桩身压缩变形等变化规律，分析了桩端注浆对承载特性的影响，验证了设计参数。     

隧道工程塌方治理及工程实例

隧道塌方是隧道施工中比较常见的事故。在广泛分析隧道塌方工程实例的基础上,对隧道塌方的原因、表现形态及有效处理措施等进行系统归纳和总结,使之系统化,可以作为事故处理时的参考。同时,结合某工程塌方实例,给出了比较具体的处理方案。该方案可以作为塌方量大、地质条件差等特殊塌方事故处理的借鉴。     

参数反演法在深厚嵌岩群桩基础受力分析中的应用

桥梁群桩基础承载性能数值计算结果与岩土参数的选取密切相关,为探讨更为符合实际工程地质情况的群桩基础受力计算模式,采用MATLAB编制的改进BP神经网络与遗传算法相结合的遗传神经网络计算程序,建立参数反演算法.该方法首先利用改进的BP神经网络对正交设计的样本数据进行训练,然后采用遗传算法进行最优求解.基于戛洒江特大桥深厚...     

基于驾驶员特征的汽车自适应巡航控制研究

汽车自适应巡航控制系统(ACC)是当前汽车驾驶员辅助系统研究中的热点课题之一。在介绍ACC原理和对驾驶员行为特征进行分析的基础上，建立了2自由度ACC控制模型，并对模型跟随前车和前车切入情况进行了模拟分析。     

驾驶人熟悉程度对其安全驾驶行为的影响研究综述

驾驶人作为人-车-路-环境复杂系统中最核心的因素,在交通安全中发挥最为关键的作用。聚焦驾驶人熟悉程度这一因素对道路交通事故的影响,系统地梳理和分析了驾驶人熟悉程度与交通事故的关系及其影响安全驾驶的机理等相关研究及成果。首先,基于驾驶人熟悉程度的距离维度和频率维度识别标准,分析了驾驶人对道路、环境及车辆的熟悉程度与其发生交通事故概率的关联性;其次,从驾驶人控制行为、路径选择行为及视觉行为等角度归纳了驾驶人熟悉程度影响其安全驾驶的机理;最后,就该领域面临的挑战及未来的研究趋势进行了分析和探讨,提出进一步标准化驾驶人熟悉程度指标的方法,为驾驶安全程度评价及提高交通安全提供了理论基础。针对已有相关研究的局限性及机理研究中尚不明朗的问题,后续研究需从认知心理学方面探究因道路、环境、车辆等驾驶人熟悉程度影响其安全驾驶的机理,进一步将视觉特征指标与生理指标结合以量化驾驶人熟悉程度,将此纳入到道路选择模型中。同时,从生理指标角度客观衡量驾驶人熟悉程度对其乘坐舒适度的影响,这些为提升自动驾驶技术接受度、交通安全及车辆安全提供强有力的理论基础。