Journal Info

(Founded in 2001 bimonthly )

Responsible Institution:The Ministry of Education of the People's Republic of China (MOE)
Sponsor:ChangAn University
Publisher:Editorial Department of Journal of Traffic and Transportation Engineering
Chief Editor:Aimin sha
Address: Editorial Department of Journal of Traffic and Transportation Engineering, Chang 'an University, Middle Section of South Second Ring Road, Xi 'an, Shaanxi
Post Code:710064
Phone:029-82334388
Domestic Distribution:Shaanxi Provincial Newspapers and Periodicals Distribution Bureau of China Post Group Co. Ltd
Foreign Sales:China International Book Trade Group Co. Ltd
Standard Number:
ISSN1671-1637 CN61-1369/U CODEN JYGXAS

Collection of Source JournalsMore>

  • Ei Compendex(美国《工程索引》
  • AJ (俄罗斯《文摘杂志》)
  • INSPEC(英国《物理学、电技术、计算机及控制信息社数据库》)
  • JST China(《日本科学技术振兴机构中国文献数据库》)
  • CSA: Technology(美国《剑桥科学文摘:工程技术》)
  • Scopus(荷兰《斯高帕斯数据库》)
  • IC(波兰《哥白尼索引》)
  • CSCD(《中国科学引文数据库》核心库)
  • GCJC(《中文核心期刊要目总览》(第7版))
  • CAJCED(《中国学术期刊综合评价数据库》
  • CSTPCD(《中国科技论文与引文数据库》)
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Review
From engineering science towards engineering technology: development and prospect of transportation and vehicle engineering in new era
WANG Zhi-zhong, PI Da-wei, WU Bing
Abstract: The National Natural Science Foundation of China (NSFC) has actively promoted its reform, and has developed the technology and science sector. According to the essential requirements and main economic challenges of China, the NSFC has attempted to solve the underlying core technical and scientific problems and has stimulated the scientific research. As an important part of NSFC's technology sector, the transportation and vehicle engineering discipline should seriously and proactively respond to the NFSC targets and adjust to its funding policy in the discipline in a timely manner. Transportation and vehicle engineering studies are demand-driven and future-oriented. They integrate various types of technology and bring different fields together. In this study, the differences between transportation elements of different transportation systems and their uniqueness were analyzed from the perspective of "small discipline, large industry" to avoid blind sorting of the so-called "common scientific problems" of industry and applications. The development of an engineering science and engineering technology evaluation system based on RAMS theory, i.e., reliability, availability, maintainability, and safety, was proposed. The characteristics of each transportation system and the differences in their scientific bases were carefully examined to establish a selection method for key funding directions and feasible technical routes based on RAMS. In this way, the application of the proposed method can be boosted in project approval, application, evaluation, and post evaluation. The rapid and efficient transformation of scientific achievements can then be realized such that China can become a great transportation power. 8 refs. More>
2021, 21(5): 1-5.   doi: 10.19818/j.cnki.1671-1637.2021.05.001
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Rise and future development of Chinese high-speed railway
XIONG Jia-yang, SHEN Zhi-yun
Abstract: The high-speed railway of China is an important part of the development of the world high-speed railway. The development and rise of Chinese high-speed railway were reviewed from the historical perspective (the inevitability of human society development) and the global perspective (the continuation of the world high-speed railway development). The timeline of the world high-speed railway development was analyzed from a macro point of view and the encouragement of the four worldwide industrial revolutions to the major advances of transportation technology was expounded. It is pointed out that the development of the high-speed railway goes through four stages: ferment, exploration, mature and development. The United States first suggested building high-speed railway, but it is still in the ferment stage. The high-speed railways of Japan, France and Germany are in the exploration stage. Only the Chinese high-speed railway has entered a rapid development stage. Based on the great achievements of Chinese high-speed railway, this paper expounded the path of introduction, digestion, absorption, innovation, and independent innovation in the process of Chinese high-speed railway development. The significant achievements have been made, on one hand, on the policy level, mainly due to Chinese efforts of taking the high-speed railway exploration experience of other countries and Chinese governmental ability of concentrating resources to accomplish large projects, integrating the advantages of enterprises, universities, and research institutes, and creating a national rail transit technology innovation system. On the other hand, from a technical perspective, the main reason of Chinese great achievements in high-speed railway lies in three important breakthroughs, which are technical breakthrough, theoretical breakthrough, and experimental breakthrough. The technical challenges faced by the development of high-speed railway and the research progress of key technologies of high-speed railway were discussed. The directions of the development of wheel-rail based high-speed transit and high-speed maglev in the post high-speed railway era were prospected, and the future development concepts of digital, intelligent, and smart high-speed railways were proposed so as to provide a reference for the future development of Chinese high-speed railway and to help to realize the great dream of building a great nation with modern transportation. 2 tabs, 25 figs, 40 refs. More>
2021, 21(5): 6-29.   doi: 10.19818/j.cnki.1671-1637.2021.05.002
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Review on customized bus route optimization
MA Chang-xi, HAO Wei, SHEN Jin-xing, WANG Chao, DU Bo
Abstract: To comprehensively review the research progress in customized bus route optimization, the relevant literatures were classified and analyzed from three aspects including optimization objective, issue scenario, and solution algorithm. Analysis results show that researches on the single-objective optimization of customized bus routes have mainly focused on the travel time, operating mileage, operating cost, operating revenue, and total system cost formed by the linear weighting of multiple costs. However, research on the multi-objective optimization was mainly achieved by simultaneously considering two or three objectives, including the operating cost, travel cost, and service quality. According to the number of departure and arrival stations, the issue scenarios of customized bus route optimization problems can be divided into three types including one-to-one, many-to-one, and many-to-many. Research on the time impedance scenarios between different stops mainly focuses on the static time impedance, and less on the dynamic time impedance. Research on the scenario of travel demand mainly focuses on the static travel demand, and two-stage optimization strategies are generally used to solve dynamic travel demand scenarios. Since the route optimization problem of customized public transportation is a special vehicle route optimization problem, the precise solution algorithm is suitable for the analysis of small travel demand. For the practical problem of large-scale travel demand, the heuristic intelligent algorithm is generally used. In future studies, the optimization of customized bus routes needs to consider the influence of the parking yard settings, stop selection, and formulate particular time window attributes for different types of travelers. Besides, in the context of a big data environment, how to take into account real-time travel demand and operating cost constraints and provide differentiated customized bus routes will also be a challenging research direction. 5 tabs, 6 figs, 61 refs. More>
2021, 21(5): 30-41.   doi: 10.19818/j.cnki.1671-1637.2021.05.003
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Review on nano clay modified asphalt based on flame retardant and smoke suppression
YANG Xiao-long, SHEN Ai-qin, JIANG Yi-xin, WU Han-song, WANG Guang-chen
Abstract: The pyrolysis combustion mechanism of asphalt material was analyzed, and the test methods for flame-retardant and smoke-suppression performance of asphalt materials were concluded. The types, advantages, and disadvantages of commonly used asphalt flame retardants in domestic and overseas were investigated. The commonly used flame-retardant technologies of tunnel asphalt materials were studied, and the flame-retardant and smoke-suppression mechanism of nano-modified asphalt was evaluated. The influence of nano-clay on the road performance of asphalt materials was examined in terms of the high- and low-temperature performances, moisture stability, and aging performance. Moreover, the future research directions for flame-retardant and smoke-suppression asphalt materials for tunnels were assessed. Research results show that the flame retardant used in tunnel asphalt materials should have high synergistic flame-retardant and smoke-suppression effects, and the metal hydroxide and nano materials have great application potential. The flame-retardant and smoke-suppression performance testing of asphalt materials mainly includes polymer flame-retardant test methods, but these methods are inconsistent with the actual combustion state of asphalt pavement. Therefore, it is necessary to supplement the flame-retardant and smoke-suppression performance test methods and standards for asphalt materials. Nano-modified materials, such as the nano clay, significantly inhibit the smoke release of hot asphalt. However, current research mainly focuses on the flame-retardant mechanism of nano-materials and polymers, and there is a lack of systematic research on the flame-retardant and smoke-suppression mechanism of nano-modified asphalt. Nano clay significantly improves the high-temperature, moisture stability, and aging performances of asphalt, but there is controversy in the study of low-temperature performance in domestic and overseas. Investigating the technology for the smoke control of hot mix asphalt mixture, metal hydroxide and nano-clay synergistic flame-retardant technology, and flame-retardant performance test methods for asphalt materials should be the focuses of future research on tunnel flame-retardant and smoke-suppression asphalt materials. 3 tabs, 8 figs, 144 refs. More>
2021, 21(5): 42-61.   doi: 10.19818/j.cnki.1671-1637.2021.05.004
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Road and railway engineering
Effect of material deterioration on slab ballastless track performance under frost heaving and freezing-thawing
YAN Bin, LOU Xu-rui-li, XIE Hao-ran, CHEN Wei, CHENG Rui-qi
Abstract: Taking the slab ballastless track in the frost heaving area of the Harbin-Dalian High-Speed Railway subgrade as the research object, the deterioration laws of materials properties under freezing-thawing cycles were investigated through the axial compression and splitting tensile failure tests on the standard cubic specimens of C60, C40 concrete and mortar under rapid freezing-thawing cycles. On this basis, a spatial finite element model was established for a CRTS Ⅰ slab ballastless track-subgrade frost heaving and freezing-thawing, considering the limit retaining boss, ring-shaped resin and interlayer bonding contact properties. The static properties of tracks after the freezing-thawing damage were studied, and the stress states and damage characteristics of the base plate were revealed. Research results demonstrate that the use of high strength grade concrete considerably decelerates the material deterioration and erosion due to the freezing-thawing cycle. Intense freezing-thawing cycles remarkably deteriorate the contact state of the structural interface. As the number of freezing-thawing cycle increases, the materials properties of mortar layer and base plate worsen significantly, their elastic moduli, interlayer bonding strengths, and axial tensile strengths decrease substantially. The peak compressive strengths of C60, C40 concrete and mortar decrease by 14.7%, 34.6%, and 29.9%, respectively, after 300 freezing-thawing cycles compared to those without any freezing-thawing cycles. The axial tensile strength of cementation interface between the C60 concrete and the mortar decreases by 90.6%. The axial tensile strengths of C60, C40 concrete and mortar decrease by more than 56%. Under the typical frost heaving condition (the frost heaving wave length is 10 m, and the frost heaving peak is 8 mm), the maximum tensile stress is observed at the upper surfaces of all structural layers of the track at the frost heaving center, whereas the maximum compressive stress is observed at the foot of the frost heaving wave. As the number of freezing-thawing cycle increases, the maximum tensile stresses of track slab and base plate also increase. Hence, when designing slab ballastless tracks in cold areas, the base plate is the main control component, and the frost heaving in the middle of the base plate is a highly unfavorable condition. 6 tabs, 11 figs, 32 refs. More>
2021, 21(5): 62-73.   doi: 10.19818/j.cnki.1671-1637.2021.05.005
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Stiffness deterioration rule of elastic iron plate of high-speed turnout and its influence on speed increase
WANG Pu, WANG Shu-guo, GE Jing, YANG Dong-sheng
Abstract: A tracking test was conducted to evaluate the damage development and stiffness evolution of the elastic iron plate of high-speed turnouts. Based on the measured data, a vehicle-turnout coupling dynamics calculation model was established, and the influence of stiffness deterioration of the elastic iron plate on the vehicle-turnout dynamic characteristics was analyzed. The adaptability of high-speed turnout to the further increase of operation speed under deteriorated stiffness was studied. Analysis results show that with the long-term use of the elastic iron plate of high-speed turnout, a series of damages appear, including rubber aging, cracking, separation, falling off, and rusting of iron components. For both the ballast and ballastless turnouts, the ratios of dynamic stiffness to static stiffness of iron plates change slightly, whereas the static stiffnesses increase. The static stiffness of the iron plate of ballast turnout shows evident changes at the initial stage, and the growing rate can exceed 60% after 3 years of service. The static stiffness of the iron plate of the ballastless turnout in the general area can increase maximum by 30%. The stiffness change is smaller than that of the ballast turnout. The static stiffness of the iron plate of the ballastless turnout changes rapidly in the cold, windy, and sandy areas. The gradual stiffness deterioration of the elastic iron plate of high-speed turnout has an effect on the dynamic performances. Under stiffness deterioration, the rail deformations in the turnout zone decrease, the wheel-rail dynamic interactions increase, and the safety parameters increase. The moving trajectories of the vehicle and wheelset are basically unchanged, but the vibration of both the wheelset and vehicle intensifies. Under stiffness deterioration of the elastic iron plate of the high-speed turnout, the increase in operation speed leads to further deterioration of the vehicle-turnout system dynamic performances, and the margins of safety and fatigue further reduce. The stiffness deterioration reduces the adaptability of the high-speed turnout to the speed increase. To expand the scope of raising speed, the stiffness deterioration of the elastic iron plate in the turnout zone should be considered. Some elastic iron plates should be replaced appropriately to ensure the running safety and stability. 2 tabs, 9 figs, 30 refs. More>
2021, 21(5): 74-83.   doi: 10.19818/j.cnki.1671-1637.2021.05.006
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Measurement method of all-wave airport runway roughness
QIAN Jin-song, CEN Ye-bo, LIU Dong-liang, LI Jun-shi, LIU Shi-fu
Abstract: Combined with vehicle-mounted laser profiler and global navigation satellite mobile positioning system, a method for measuring the all-wave roughness of an airport runway was proposed. The on-situ test was carried out at Jinan Yaoqiang International Airport, and the repeat test and level were used to verify the reliability of this measurement method. A virtual prototype model of B737-800 was built using ADAMS/Aircraft software, and the simulation of aircraft taxiing under the measured runway roughness data was carried out. The influence of the measured data characteristics of the runway under different measuring methods, taxiing speeds, and aircraft positions on the aircraft vibration responses was explored. Research results show that the proposed measuring method can obtain all-wave runway roughness data, which makes up for the defect that the laser profiler is unable to capture wavelengths of above 14 m. When the speed is 80 km·h-1, the fluctuant amplitudes of aircraft vibration responses under all-wave roughness runway are 1.25-2.39 and 1.19-1.85 times that under a long-wave roughness and short-wave roughness, respectively, indicating that aircraft vibration responses under the real runway roughness may be underestimated if only considering long-wave roughness or short-wave roughness. With the increase of aircraft taxiing speed, the differences of aircraft vibration acceleration increase gradually under the all-wave roughness and short-wave roughness. While the differences of dynamic load coefficients first increase and then decrease, and reaching the maximum at the speed of 160 km·h-1, indicating that the effect of long-wave roughness on the runway is more obvious during high-speed taxiing. Compared with the short-wave roughness condition, the increase of cockpit acceleration under all-wave roughness is 0.062 m·s-2 higher than that at the center of gravity on average, and the increase of dynamic load coefficient of nose landing gear is 0.039 higher than that of the main landing gear on average, which shows the effect of long-wave roughness on the vibration in the front part of aircraft is greater than that in the center part of aircraft. In addition, with the increase of taxiing speed, the differences first increase and then decrease. The difference of acceleration is most obvious at speeds between 80-120 km·h-1 with the peak at around 0.078 m·s-2, while the peak of difference of dynamic load coefficient is 0.062 at the speed of 160 km·h-1. 2 tabs, 12 figs, 30 refs. More>
2021, 21(5): 84-93.   doi: 10.19818/j.cnki.1671-1637.2021.05.007
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Low temperature performance evaluation indexes of asphalt binder based on EBBR test
FENG De-cheng, CUI Shi-tong, YI Jun-yan, WANG Dong-sheng
Abstract: Focusing on the evaluation indexes of the low temperature performance of asphalt binders, based on rheological bending beam rheometer (BBR) and extended bending beam rheometer (EBBR) tests, the low temperature rheological properties of the extracted asphalt, aging base asphalt and modified asphalt on actual pavements were analyzed. The low temperature performance evaluations of the asphalts were carried out using the traditional stiffness modulus and modulus changing rate. The equivalent low temperature design temperature index and the temperature difference value index were proposed. Simulations in different curing environments were conducted, and the influencing factors of physical hardening of newly prepared and extracted asphalt at low temperature were studied using low temperature grade loss index. Different sources and types of asphalt test results were used to verify each other, the above indexes were compared and analyzed in terms of anti-interference ability, stability, evaluation accuracy, intuitiveness, and difficulty in obtaining indexes. The abilities of four indexes in distinguishing and evaluating the low temperature performance of asphalt were established. Research results show that the laboratory rheological analysis of the extracted asphalt can reflect the low temperature crack resistance level of the pavement structure. The modulus of the asphalt in the severely cracked section is significantly higher than those in the other sections, and the value difference can reach about 130 MPa. The newly prepared SBS modified asphalt and the extracted asphalt have a high consistency at low temperature loads, and the modulus deviation is lower than 15%. It can effectively establishes the relationship between laboratory research and actual pavement disease treatment needs. The stability of traditional index data is weak, and the confidence is only 64.7%-82.3%, which is difficult to satisfy the research needs. The applications of temperature difference value index and low temperature grade loss index is also restricted, which still needs more in-depth research. 4 tabs, 10 figs, 32 refs. More>
2021, 21(5): 94-103.   doi: 10.19818/j.cnki.1671-1637.2021.05.008
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Traffic sign recognition method based on HOG-Gabor feature fusion and Softmax classifier
LIANG Min-jian, CUI Xiao-yu, SONG Qing-song, ZHAO Xiang-mo
2017, 17(3): 151-158.  
[Abstract](475) [PDF 2110KB](532)
摘要:
为了提高交通标志识别的正确率和实时性,提出了一种基于HOG-Gabor特征融合与Softmax分类器的交通标志识别方法。采用 Gamma矫正方法提取HOG特征,采用对比度受限的自适应直方图均衡化方法提取Gabor特征,基于线性特征融合原理,将提取的HOG和 Gabor特征向量直接串联,得到刻画交通标志的融合特征向量,采用Softmax分类器对融合特征向量进行分类,采用德国交通标志识别 基准(GTSRB)数据库测试了所提方法的有效性,比较了基于单特征与融合特征的交通标志识别效果。试验结果表明:在图像增强过程 中,针对HOG特征,采用Gamma矫正方法的分类正确率最大,为97.11%,针对Gabor特征,采用限制对比度的直方图均衡化方法的分类正确 率最大,为97.54%; 采用Softmax分类器的最小分类正确率为97.11%,耗时小于2 s; 针对HOG-Gabor融合特征,采Softmax分类器的识 别率高达97.68%,因此, 基于HOG-Gabor特征融合与Softmax分类器的交通标志识别方法的识别率高,实时性强。
Review of pavement detection technology
MA Jian, ZHAO Xiang-mo, HE Shuan-hai, SONG Hong-xun, ZHAO Yu, SONG Huan-sheng, CHENG Lei, WANG Jian-feng, YUAN Zhuo-ya, HUANG Fu-wei, ZHANG Jian, YANG Lan
2017, 17(5): 121-137.  
[Abstract](673) [PDF 1090KB](1792)
摘要:
总结了路面检测重要研究成果,分析了路面损坏、平整度、车辙、抗滑性能(构造深度)和结构强度(弯沉)检测技术的发展现状,研究了路面检测技术的不足与发展方向。研究结果表明:国内外路面检测技术的发展经历了3个阶段,从早期传统的人工检测到20世纪末的半自动化检测,发展到目前的无损自动检测; 无损自动检测的主要特点是快速与智能化,采用多源传感器协同工作,并且集成在多功能道路检测车上,能够同时检测路面损坏、平整度、车辙、抗滑性能和结构强度以及道路线形与沿线设施等; 在路面损坏检测方面,采用数字图像检测技术,实现了路面裂缝的快速检测; 在路面平整度检测方面,采用激光位移传感技术,实现了快速自动化检测; 在路面车辙检测方面,采用激光和数字图像技术,实现了非接触智能化检测; 在路面抗滑性能和结构强度检测方面,建立了铺砂法与贝克曼梁法检测结果的相关关系,实现了基于激光技术的路面构造深度与弯沉快速检测; 为了减少外界因素对现有检测技术和检测设备的干扰,提高检测信号的信噪比,应该开发适合各种工况下的路面检测和数据处理方法,实现路面检测高效化与智能化。
Review of car-following models of adaptive cruise control
QIN Yan-yan, WANG Hao, WANG Wei, NI Dai-heng
2017, 17(3): 121-130.  
[Abstract](647) [PDF 928KB](1420)
摘要:
分析了自动驾驶汽车自适应巡航控制(Adaptive Cruise Control, ACC)和协同自适应巡航控制(Cooperative Adaptive Cruise Control, CACC)车辆跟驰模型,从系统控制原理、车车通信技术与车间时距方面阐述了ACC与CACC车辆的异同点; 将目前主 流ACC/CACC车辆跟驰模型分为3类:基于智能驾驶的车辆跟驰模型、加州伯克利大学PATH实验室车辆跟驰模型与基于控制论的车辆跟 驰模型,总结3类车辆跟驰模型的建模思路与主要优缺点; 从道路通行能力、交通安全和交通流稳定性3方面,分析了ACC/CACC车辆对 交通流特性的影响,及其研究现状与未来发展趋势。研究结果表明:不同的ACC/CACC车辆跟驰模型对通行能力的影响存在较大差 别,ACC/CACC车辆有利于提升交通安全性,但由于缺乏统一的安全性评价指标,难以量化ACC/CACC车辆对交通安全性的影响程度; 小 规模实车试验验证了ACC车辆具有不稳定的交通流特性,否定了ACC车辆稳定性数值仿真结果,而数值仿真试验和小规模实车试验均表 明CACC车辆可较好提升交通流稳定性,因此,完全依赖于计算机仿真试验无法获得令人信服的结论,实车试验是ACC/CACC研究的必要 途径; 为了完善ACC/CACC在交通领域的研究,应构建不同ACC/CACC车辆比例下的混合交通流基本图模型、智能网联环境下的 ACC/CACC车辆跟驰模型建模方法与ACC/CACC混合交通流稳定性解析方法。
Review of ultra-high performance concrete shrinkage
CHEN Bao-chun, LI Cong, HUANG Wei, AN Ming-zhe, HAN Song, DING Qing-jun
2018, 18(1): 13-28.  
[Abstract](705) [PDF 1416KB](820)
摘要:
分析了超高性能混凝土(UHPC)的收缩特性及其随时间发展的一般规律,总结了材料组成、养护制度与内部温湿度场对UHPC收缩的影响。研究结果表明:UHPC收缩早期(0~7 d)发展快,占总收缩的61.3%~86.5%,中期(7~28 d)发展缓慢,占总收缩的13.5%~27.9%,后期(28 d后)趋于稳定; UHPC以自收缩为主,占总收缩的78.6%~90.0%,是早期开裂的主要诱因; 收缩测试起始时间可取试件成型后1 d(24 h),终止时间可取90 d或120 d; 在结构设计时,可参考各国规范取收缩为500~800 με,热养护后可不考虑残余收缩; 对于收缩预测模型,各国规范尚未统一,多借鉴现有的收缩模型,应完善与修正收缩预测模型; 对于材料组成,目前集中于纤维、矿物掺合料的种类和掺量对收缩的定量影响,且各组分对收缩的影响不同,评价指标较为单一,应结合结构用途、制备工艺与施工过程等进行综合评价; 对于内部温度与湿度场,研究对象主要集中于28 d后的普通混凝土与高强高性能混凝土,应深入研究胶凝材料含量大、组分差异性明显、活性矿物掺合料掺量高的UHPC早期内部温度与湿度场; 为了降低收缩,基本采用内养护,添加膨胀剂、减缩剂与粗骨料等措施。可见:为了减小UHPC收缩的同时又不降低其力学性能,应该优化UHPC配比,合理使用外加剂,采取适当养护制度等措施。
Vehicle multi-target detection method based on YOLO v2 algorithm under darknet framework
LI Xun, LIU Yao, LI Peng-fei, ZHANG Lei, ZHAO Zheng-fan
2018, 18(6): 142-158.  
[Abstract](334) [PDF 43525KB](366)
摘要:
针对道路车辆目标检测传统方法需随场景变化提取不同特征,检测率较低与鲁棒性差的问题,提出了一种基于Darknet框架下YOLO v2算法的车辆多目标检测方法; 根据目标路段场景与车流量的变化对YOLO-voc网络模型进行改进,基于ImageNet数据集和微调技术获得分类训练网络模型,对训练结果和车辆目标特征进行分析后进一步调整改进的算法参数,最终获得更适合于道路车辆检测的YOLO-vocRV网络模型下车辆多目标检测方法; 为验证检测方法的有效性和完备性,采用不同车流密度进行了车辆多目标检测试验,并与经典YOLO-voc、YOLO9000模型进行了对比; 采用改进YOLO-vocRV网络模型,选取20 000次迭代,分析了多目标检测结果。试验结果表明:在阻塞流样本条件下,YOLO9000网络模型检测率为93.71%,YOLO-voc网络模型检测率为94.48%,改进YOLO-vocRV网络模型检测率达到了96.95%,因此,改进网络模型YOLO-vocRV检测率较高; YOLO-vocRV模型精确度和召回率均聚集在0.95,因此,在获得较好精确度的条件下损失的召回率明显较小,达到了很好的折中; 采用混合样本训练后,基于YOLO-vocRV模型的车辆多目标检测方法的检测率在自由流状态下可达99.11%,同步流状态下可达97.62%,阻塞流状态下可达到97.14%,具有较小的误检率和良好的鲁棒性。
Seismic performance of prefabricated assembled pier with grouted sleeve and prestressed reinforcements
GE Ji-ping, YAN Xing-fei, WANG Zhi-qiang
2018, 18(2): 42-52.  
[Abstract](200) [PDF 1976KB](480)
摘要:
针对轨道交通预制拼装桥墩的受力特点,提出了采用灌浆套筒和预应力筋连接的拼装方案; 设计了3种不同类型桥墩,包括整体现浇试件(RC)、预应力钢绞线和灌浆套筒连接的预制拼装试件(PCSS)与精轧螺纹钢筋和灌浆套筒连接的预制拼装试件(PCTS),采用拟静力试验方法分析了各种桥墩的各种拟静力指标,比较了桥墩的抗震性能。试验结果表明:PCSS和PCTS试件的各指标非常接近,最大误差为2.2%; 灌浆套筒会使传统塑性铰区上移至套筒顶部,说明灌浆套筒对传统塑性铰区域具有局部增强作用,建议对塑性铰的箍筋加密区高度应额外增加1个套筒高度; 采用预应力筋使试件的混凝土轴压力增大了1倍,相应的开裂荷载也增大了约1倍; PCSS试件的屈服荷载和极限荷载正负向均值比RC试件分别提高了31%和34%,等效屈服位移、极限位移和偏移率均值分别比RC试件提高了17%、13%、13%,但是PCSS试件的延性系数平均降低了10%; 在偏移率为6%时,PCSS试件的残余位移均值是RC试件的61%,显示了较好的自复位能力; 与RC试件相比,PCSS试件的刚度提高了13%。相比于精轧螺纹钢筋,钢绞线可以适当弯曲与成束,面积调整灵活,因此,采用无黏结预应力筋和灌浆套筒连接的桥墩试件具有良好的使用性能和抗震性能,可作为预制拼装轨道桥墩的推荐方案。
Review of construction and technology development of arch bridges in the world
CHEN Bao-chun, LIU Jun-ping
2020, 20(1): 27-41.   doi: 10.19818/j.cnki.1671-1637.2020.01.002
[Abstract](548) [PDF 22556KB](498)
摘要:
为了解近20年世界拱桥的发展情况,分析了钢拱桥、混凝土拱桥和钢管混凝土拱桥等拱桥的建设和技术创新,展望了拱桥今后的发展趋势。分析结果表明:在活载比重较大、动力问题比较突出的高速铁路桥梁中,拱桥刚度大,应用优势突出。在跨径方面,3种大跨径拱桥的平均跨径分别为464、370和425 m,且最大跨径不断增大,以钢管混凝土拱桥最为明显。在材料方面,高强钢在钢拱桥中的应用趋势并不明显; 混凝土拱桥的材料强度随着跨径的增大而不断提高,超高性能混凝土已经得到应用; 钢管混凝土拱桥的拱肋材料强度在不断提高; 超高性能砂浆的提出将有助于提高圬工拱桥的竞争优势。在结构方面,主拱采用新材料和钢腹板(杆)-混凝土组合截面,与其他结构形成组合结构,以及桥面连续化、轻型化和强调强健性,是重要的技术进步。在施工技术方面,钢管混凝土劲性骨架施工法、转体施工法和快速施工法等的发明,推动着拱桥施工技术的进步。在结构创新与技术进步的推动下,由于拱桥在美观、经济、结构等方面的独特优势,今后仍将被大量修建; 超高性能混凝土有望为拱桥发展带来革命性的变化; 在跨径方面,近期可望取得明显突破的是混凝土拱桥; 桥面系与主拱共同受力、连续化、轻型化和强调强健性也是重要发展方向。
Optimization of departure frequency for bus rapid transit with multi-type vehicles under time-dependent demand
DAI Cun-jie, LI Yin-zhen, MA Chang -xi, CHAI Huo
2017, 17(1): 129-139.  
[Abstract](547) [PDF 1192KB](870)
摘要:
以公共交通网络中的单条快速公交线路为研究对象,分析了快速 公交车辆的发车间隔特征和沿线乘客出行需求的时间依赖特征; 考虑 多类型公交车辆协同作业,以所有乘客的累计等待时间最小和车辆的平 均满载率最大为目标,以最小、最大发车时间间隔和车辆运能的供需比 为约束,建立多类型快速公交车辆协同作业模式下的发车频率优化模型 ; 利用改进的非支配排序遗传算法对模型求解,并应用兰州市快速公交 数据进行实例分析。分析结果表明:乘客累计等待时间分别取最大值、 中间值和最小值时,优化后的发车次数比实际发车次数分别降低22.9% 、16.7%和8.4%,对应的车辆平均满载率分别提高27.4%、15.1%和3.9%; 与单一类型的快速公交车辆独立作业相比,2种类型的快速公交车辆协 同作业的平均发车次数增加7.9%,平均乘客累计等待时间降低23.8%。 可见,根据乘客出行需求的时间依赖特征,合理安排不同类型的快速公 交车辆协同作业,对发车频率进行优化,能有效减少乘客等待时间,提高 公交车辆利用效率。
Review on location-routing problem
HU Da-wei, CHEN Xi-qiong, GAO Yang
2018, 18(1): 111-129.  
[Abstract](434) [PDF 1162KB](1027)
摘要:
研究了定位-路径问题(LRP),总结了国内外LRP模型及其扩展模型,比较了LRP模型求解算法的适用性,分析了LRP测试算例的节点分布和数据规模,提出了LRP研究的主要方向。研究结果表明:LRP模型从基于基础网络的最简化问题(带容量约束的LRP, CLRP)向多方向模型进行扩展,包括基于网络复杂化的LRP扩展,如特定网络系统的多目标LRP(MOLRP)、同时取送货LRP(LRPSPD)、接驳转运中心LRP(CDCLRP)、两阶段LRP(2E-LRP)、选址-弧路径问题(LARP)、卡车和拖车路径问题(TTRP)与设施地点为二维连续的LRP(PLRP),基础网络参数不确定化的LRP,包括带模糊数据的LRP与多计划周期LRP(MPLRP),且正在向更切合实际的问题如高度集成、不确定与动态LRP发展; LRP算法方面,精确算法仅可用于求解小规模LRP,主要LRP求解算法由早期的智能算法逐渐转向元启发式算法、基于邻域搜索优化的算法与混合算法方向发展,这些改进算法均基于特定LRP设计,具有更好的求解性能,尤其是采用基于多种破坏和修复因子的自适应大邻域搜索算法求解大规模LRP取得了较好的解,且其改造性极强; 常用LRP测试算例的节点呈现均匀分布、堆分布及均匀与堆混合分布,且逐渐产生了适用于2E-LRP与LRPSPD等扩展LRP的测试算例; 根据物流市场环境变化和需求,提出LRP未来扩展研究的主要方向,包括多阶段LRP的扩展(如2E-LRPSPD、考虑库存的2E-LRP等)、节点二维连续的LRP、客户含优先级的带竞争或盈利LRP、混合不确定LRP等切合实际的问题; 提出了LRP求解算法未来方向,包括设计新型精确算法求解中、大规模LRP,设计更准确更高效的组合启发式算法与应用近似算法求解LRP及扩展LRP的最优解。
Distribution characteristics of traffic crash data of freeway based on statistics and hypothesis test
MENG Xiang-hai, QIN Wei, HUO Xiao-yan
2018, 18(1): 139-149.  
[Abstract](514) [PDF 950KB](1079)
摘要:
为了研究高速公路基本路段上交通事故数据的分布特征,将事故数、伤亡事故数、事故死亡人数与事故受伤人数归类为离散型事故数据,将事故间隔时间与平均每年每公里事故数归类为连续型事故数据; 对于离散型事故数据,采用均匀划分法、动态聚类法与滑动窗法划分高速公路统计区段,运用泊松分布、负二项分布、零堆积泊松分布与零堆积负二项分布对事故数据进行拟合; 对于连续型事故数据,以收费区间为路段划分标准,用正态分布、负指数分布进行事故数据拟合; 运用皮尔逊卡方值对各种拟合结果进行拟合优度检验。研究结果表明:在各种区段上,事故数均服从负二项分布,有些情况下会同时服从负二项分布与泊松分布,伤亡事故数与事故死亡人数主要服从零堆积泊松分布或零堆积负二项分布,拟合优度检验中的概率均大于0.05; 平均每年每公里的事故数比较符合正态分布,而事故间隔时间则主要服从负指数分布,拟合优度检验中的概率也均大于0.05; 交通事故数据的统计分布特征是建立事故预测模型与事故多发点鉴别的前提条件之一,而事故间隔时间可作为安全可靠度的度量指标。
Influences of air spring models on dynamics performance of railway vehicle
WU Xing-wen, CHI Mao-ru, ZHU Min-hao, ZENG Jing, YANG Fei
2013, 13(2): 54-59.  
[Abstract](556) [PDF 1297KB](0)
Abstract:
The equivalent model, linear model and nonlinear model of air spring were established, and the influences of three models on the ride comfort of straight track and the safety of curve track were studied. Analysis result shows that the accuracy of equivalent model is smaller for the calculation of ride comfort of straight track, but the linear model and the nonlinear model can provide better accuracy. The linear model is simpler than the nonlinear model, therefore, the linear model is suggested to be adapted for the calculation of ride comfort of straight track. Since the nonlinear model of air spring can reflect the dynamic performance of air spring and provide better accuracy compared with the linear model and the equivalent model, therefore, the nonlinear model is recommended to be used in the safety calculation of curve negotiation. 12 figs, 15 refs.
Relationship among asphalt component, viscosity and adhesion in triangular coordinate system
FU Zhen, YAN Xi-li, CAI Ting, MA Feng, WANG Lin-bing
2014, 14(3): 1-7.  
[Abstract](658) [PDF 1163KB](9)
Abstract:
In order to assess the influences of asphalt component and composition on asphalt technical properties, thirteen types of pavement petroleum asphalts and two kinds of typical aggregates were selected. The relationship among asphalt component, viscosity and adhesion was investigated by using tests of four-component, apparent viscosity and adhesion. The characterization method of asphalt four-component test result by using triangular coordinate system was put forward. The asphalt characteristic triangle was drawn with four-component data. The characteristic of asphalt composition was represented by inertia moment. The asphalt pyramid was drawn based on asphalt four-component data and the relationship among its geometry characteristics, viscosity and adhesion was analyzed. Analysis result indicates that except asphalt components, its composition differences also have influences on asphalt viscosity and aggregate adhesion. For the asphalts with same penetration grade and different brands, triangular coordinate analysis result shows the aggregate adhesion increases with the increase of the inertia moment of asphalt four-component characteristic triangle. 6 tabs, 6 figs, 18 refs.

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