西藏东南部沥青路面常见病害及成因分析

西藏东南部特殊的气候条件引起的沥青路面病害直接影响到路面的使用性能和路面的耐久性,它与沥青混合料类型、混合料的配合比设计、沥青品质、矿料质量、施工方法与材料的均匀性、气候特点、交通条件等有关。通过调研分析了病害与藏东南独特的气候关系,冻土、巨大的昼夜温差、长时间高频率的降雨是造成路面病害的主要因素。     

公路建设项目中降雨因子对土壤流失量的影响分析

降雨因子对水土流失量起着决定性的作用。通过在汉十高速公路上设置实验小区，用径流小区法进行了水土流失监测，并根据数理统计原理，对水土流失量及降雨量的数据进行分析，建立回归方程，研究了降雨因子与水土流失量之间的关系，并对其结果从溅蚀和径流冲刷两个方面进行了理论分析。     

盾构砂性渣土-泡沫混合物渗透性影响因素研究

渣土改良是确保土压平衡盾构在砂性地层中安全高效掘进的重要措施。目前盾构渣土常用的改良剂是泡沫剂,泡沫与砂性渣土混合后能有效降低刀盘扭矩、提高渣土的抗渗性。为研究盾构砂性渣土-泡沫混合物渗透性的影响因素,通过常水头渗透试验,从砂土级配、泡沫剂体积分数以及泡沫注入体积比3个方面分析混合物渗透系数的变化规律。结果显示： 1）混合物的渗透系数与等效粒径d20呈正相关变化; 2）随着时间的增加,混合物的渗透系数K20逐渐增加; 3）随着泡沫剂体积分数的增大,混合物的渗透系数先减小后增大; 4）当泡沫的注入体积比达到一定值时,混合物的渗透系数趋于稳定。     

普通公路车速分布特性影响因素分析

选取代表集中趋势的平均车速、15%位车速、85%位车速,代表离散程度的速度标准差作为车速分布特性的参数。结合4条普通公路速度调查结果,对道路因素、车辆因素、交通流因素与速度分布特性参数的关系进行了研究,通过实测统计数据图形的变化分析了各种因素对速度分布特性的影响。     

Incorporating human-factors in car-following models: A review of recent developments and research needs

Over the past decades there has been a considerable development in the modeling of car-following (CF) behavior as a result of research undertaken by both traffic engineers and traffic psychologists. While traffic engineers seek to understand the behavior of a traffic stream, traffic psychologists seek to describe the human abilities and errors involved in the driving process. This paper provides a comprehensive review of these two research streams.It is necessary to consider human-factors in CF modeling for a more realistic representation of CF behavior in complex driving situations (for example, in traffic breakdowns, crash-prone situations, and adverse weather conditions) to improve traffic safety and to better understand widely-reported puzzling traffic flow phenomena, such as capacity drop, stop-and-go oscillations, and traffic hysteresis. While there are some excellent reviews of CF models available in the literature, none of these specifically focuses on the human factors in these models.This paper addresses this gap by reviewing the available literature with a specific focus on the latest advances in car-following models from both the engineering and human behavior points of view. In so doing, it analyses the benefits and limitations of various models and highlights future research needs in the area.     

Empirical analysis of short period traffic counts and their efficiency: the case of Indian traffic

Short period traffic counts (SPTCs) are conducted routinely to estimate the annual average daily traffic (AADT) at a particular site. This paper uses Indian traffic volume data to methodically and extensively study the effect of four aspects related to the design of SPTCs. These four aspects are: (i) for how long, (ii) on which days should SPTCs be carried out, (iii) how many times, and (iv) on which months should SPTCs be carried out? The analyses indicate that the best durations for conducting SPTCs are 3 days (starting with a Thursday) and 7 days, for total traffic and truck traffic, respectively. Further, these counts should be repeated twice a year keeping a separation of two months between the counts to obtain good estimates of AADT at minimal cost. An additional outcome of this study has been the determination of seasonal factor values for roads in developing economies, like India.     

基于BP神经网络的隧道围岩分类

应用BP神经网络建立了隧道围岩分类模型,对其影响因素进行分析,并对模型进行优化,将训练好的分类模型运用到贵安隧道,为隧道围岩分类提供了一种简便可行的方法。     

基于灰熵法的弯沉综合修正系数影响因素分析

应用灰熵理论,分析了各影响因素对弯沉综合修正系数F影响的显著性。研究结果表明:土基模量、实测弯沉、各层模量比、路面厚度为F的主要影响因素,并将影响因素引入F的计算中,提出了新的F计算式,为确定适合于不同路面结构、不同路面厚度的F的计算式提供参考。     

王北凹隧道洞口及浅埋段安全风险评估及控制措施

受山区地形的限制,山岭隧道洞口及浅埋段地质条件一般较为恶劣,容易造成洞口失稳、大变形等风险,对隧道的安全施工形成较大隐患。基于王北凹隧道的地质勘察资料、水文地质资料及相关设计资料,通过专家调查法对隧道洞口及浅埋段风险源进行辨识与排序,对其失稳可能发生的风险等级进行了分析,并提出了相应的风险控制措施。     

影响车身后拖曳臂接附点动刚度因素研究

基于某开发车型车身后拖曳臂接附点的动刚度性能改善,研究影响动刚度因素。通过对影响动刚度因素的分解及CAE仿真计算论证,确认影响动刚度因素。指明了车身后拖曳臂接附点动刚度性能设计控制要素及解决动刚度问题的思路。