基于数据深度增强的路面病害智能检测方法研究及比较

针对路面病害人工检测方法的耗时问题和路面病害自动检测方法的检测精度问题(由于样本数据集不均衡导致),采用一种数据深度增强方法,对车载智能手机拍摄的高清路面图片数据集进行增强处理,并测试评估该数据增强方法对2种不同类型目标检测算法的提升效果.首先,鉴于实验条件及采集环境的限制,作者采用一种WGAN-GP与泊松迁移算法相融合的数据深度增强方法,通过生成不同遮挡物、不同光线条件下的道路坑槽图片,补充并均衡训练样本数据;然后,引入Faster R-CNN和基于Yolo算法的多种目标检测算法变体(Yolov5s、Yolov5m、Yolov5l、Yolov5x),通过实验比对应用数据深度增强方法后各种目标检测算法的识别精度和效率.在日本公开道路检测数据集上的实验结果显示,使用数据深度增强方法后,5种检测算法的P指标、R指标及F1指标平均提升度分别为2.8%、4.0%及3.6%;5种检测算法中,Yolov5l取得最高的F1数值,达到60.9%,若条件适宜,如在背景光线适中的测试集上,Yolov5l算法的F1数值可以达到68.7%,取得较好的效果.

Texturing and evaluation of concrete pavement surface:A state-of-the-art review

Concrete pavement is accompanied by two major functional properties,namely noise emission and friction,which are closely related to pavement surface texture.While several technologies have been developed to mitigate tirepavement noise and improve driving friction by surface texturization,limited information is available to compare the advantages and disadvantages of different surface textures.In this study,a state-of-the-art and state-of-thepractice review is conducted to investigate the noise reduction and friction improvement technologies for concrete pavement surfaces.The commonly used tests for characterizing the surface texture,skid resistance,and noise emission of concrete pavement were first summarized.Then,the texturing methods for both fresh and hardened concrete pavement surfaces were discussed,and the friction,noise emission and durability performances of various surface textures were compared.It is found that the next generation concrete surface(NGCS)texture generally provides the best noise emission performance and excellent friction properties.The exposed aggregate concrete(EAC)and optimized diamond grinding textures are also promising alternatives.Lastly,the technical parameters for the application of both diamond grinding and diamond grinding&grooving textures were recommended based on the authors'research and practical experience in Germany and the US.This study offers a convenient reference to the pavement researchers and engineers who seek to quickly understand relevant knowledge and choose the most appropriate surface textures for concrete pavements.

Advanced industrial informatics towards smart,safe and sustainable roads:A state of the art

The road is one of the most important civil infrastructures for serving society,where its service quality and life have direct impacts on the safety and comfort of users.Therefore,road construction,condition detection and monitoring,and timely maintenance are particularly important for engineers.Many engineering applications of industrial informatics approaches,like image processing technology,widely used computer-based algorithms,and advanced sensors,have been initially and gradually applied to roads.This state-of-the-art review first summarized the research on industrial applications of advanced information technologies in recent years,while analyzing and comparing the advantages and disadvantages of each technology.Especially,five topics were focused on road construction,road maintenance with decision strategy,road structure evaluation,smart sensing in the road,and cooperative vehicle infrastructure system.It is expected that advanced industrial informatics can help engineers promote the development of smart,safe,and sustainable roads.

Application of semi-analytical finite element method to analyze the bearing capacity of asphalt pavements under moving loads

To facilitate long term infrastructure asset management systems, it is necessary to determine the bearing capacity of pavements. Currently it is common to conduct such measurements in a stationary manner, however the evaluation with stationary loading does not correspond to reality a tendency towards continuous and high speed measurements in recent years can be observed. The computational program SAFEM was developed with the objective of evaluating the dynamic response of asphalt under moving loads and is based on a semi-analytic element method. In this research project SAFEM is compared to commercial finite element software ABAQUS and field measurements to verify the computational accuracy. The computational accuracy of SAFEM was found to be high enough to be viable whilst boasting a computational time far shorter than ABAQUS. Thus, SAFEM appears to be a feasible approach to determine the dynamic response of pavements under dynamic loads and is a useful tool for infrastructure administrations to analyze the pavement bearing capacity.

Study of the influence of pavement unevenness on the mechanical response of asphalt pavement by means of the finite element method

Pavement unevenness affects the vehicle operating cost, speed, riding comfort, safety, pavement service life and etc. The current mechanistic-empirical （M-E） design procedure of asphalt pavements is based on the computational model of a flat pavement instead of uneven pavement as it is the case in reality. In this paper, a tire-pavement-interaction FE model is developed to investigate the influence of pavement unevenness on the mechanical responses of asphalt pavements. For both winter and summer conditions, the strain at the bottom of the asphalt layer due to the tire load is found to decrease as the wavelength of the unevenness increases. Moreover, the strain is larger at lower speeds and decreases as the speed increases. It is found that the stress levels are higher in summer conditions than under winter conditions for the same pavement irrespective of wavelength. The fatigue life increases with increase in speed of the tire for a pavement and also increases with increase in the wavelength of the pavement unevenness. The results indicate that pavement unevenness significantly influence the mechanical responses of asphalt pavements and thus influences the service life of asphalt pavements. As a result, the current M-E design algorithm of asphalt pavements should be modified to consider the pavement unevenness to allow better design processes for asphalt pavement.

Application of semi-analytical finite element method coupled with infinite element for analysis of asphalt pavement structural response

A specific computational program SAFEM was developed based on semi-analytical finite element （FE） method for analysis of asphalt pavement structural responses under static loads. The reliability and efficiency of this FE program was proved by comparison with the general commercial FE software ABAQUS. In order to further reduce the computational time without decrease of the accuracy, the infinite element was added to this program. The results of the finite-infinite element coupling analysis were compared with those of finite element analysis derived from the verified FE program, The study shows that finite-infinite element coupling analysis has higher reliability and efficiency.

Calculation of skid resistance from texture measurements

There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature, measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components： measurement of the pavement texture by means of an optical measufin~ system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented. The concept is applied to a laboratory device called Wehner/Schulze （W/S） machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.

Application of semi-analytical finite element method to analyze asphalt pavement response under heavy traffic loads

Accurate assessment of the impact of heavy traffic loads on asphalt pavements requires a computational model which is able to calculate the response of the pavement fast and precisely. Currently the most finite element analysis programs based on traditional methods have various limitations. A specific program SAFEM was developed based on a semi-analytical finite element method to overcome the problems. It is a three-dimensional FE program that requires only a two-dimensional mesh by incorporating the semi- analytical method using Fourier series in the third dimension. The computational accuracy and efficiency of the program was verified by analytical verification previously. The experimental verification is carried out in this paper and the results show that the SAFEM is able to predict the mechanical responses of the asphalt pavement. Using the program SAFEM, the impact of heavy traffic loads was analyzed in terms of stress and strain dis- tribution, surface deflection and fatigue life. The results indicate that if the asphalt pave- ment is subjected to the heavy traffic load more, the thicknesses and stiffness of the pavement structural layers should be increased adequately in order to support the surface deflection, The compressive stress in asphalt binder course is relatively large and increases more significantly compared with that in the other asphalt layers when the axle load becomes larger. With comparison of the predicted fatigue life, the increase of the axle load will lead to the destruction of the asphalt pavement extremely easily.

Approaches for a 3D assessment of pavement evenness data based on 3D vehicle models

Pavements are 3D in their shape. They can be captured in three dimensions by modern road mapping equipment which allows for the assessment of pavement evenness in a more holistic way as opposed to current practice which divides into longitudinal and transversal evenness. It makes sense to use 3D vehicle models to simulate the effects of 3D surface data on certain functional criteria like pavement loading, cargo loading and driving comfort. In order to evaluate the three criteria mentioned two vehicle models have been created： a passenger car used to assess driving comfort and a truck-semitrailer submodel used to assess pavement and cargo loading. The vehicle models and their application to 3D surface data are presented. The results are well in line with existing single-track （planar） models. Their advantage over existing 1D/2D models is demonstrated by the example of driving comfort evaluation. Existing ＂geometric＂ limit values for the assessment of longi- tudinal evenness in terms of the power spectral density could be used to establish corre- sponding limit values for the dynamic response, i.e. driving comfort, pavement loading and cargo loading. The limit values are well in line with existing limit values based on planar vehicle models. They can be used as guidelines for the proposal of future limit values. The investigations show that the use of 3D vehicle models is an appropriate and meaningful way of assessing 3D evenness data gathered by modern road mapping systems.

聚氨酯粘结剂的透水路面砖研究

上世纪九十年代中期以来,经济发展所伴随人类居住面积和交通基础设施面积的扩张,对环境造成了重大影响,并导致发生洪水的风险增加、气候条件改变和自然水循环的巨大扭曲。现代市政污水管理系统的主要目标是促进密封区域的雨水重新回到自然水循环系统。一种可能的解决方法是采用透水性路面替代不透水路面。在城镇区域,路面砖路面常常用于将地表积存雨水渗入地下,以适应建筑占地面积比例提高的规划要求。在大多数情况下,路面地路面的透水性能归功于砖接缝处填充的透水材料;然而,这种路面的透水性能通常有限度的,因为大多数混凝土路面砖本身并不透水。由于细颗粒和杂质可能堵塞粒状填缝材料,所以无法完全保持这种透水路面在使用期限内的渗透性。本研究项目旨在开发一种以聚氨酯为胶结材料的自透水性路面砖。通过对材料强度、渗透率和表面性能的综合评价,提出方法和材料。

Characterization of road surfacing aggregates based on their mineralogical fingerprint

To ensure the safety of infrastructure users,the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate.Most studies have investigated these aggregate properties separately without considering the interrelation between one another.The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process.The investigations are based on 11 different aggregate types with a broad range of mineralogy,commonly used in Germany.The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the MicroDeval test respectively.To evaluate the impact of these tests,the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test.The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates.A correlation between the skid resistance,morphological properties and mineralogy is derived,which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers.

Preface for the special issue on “Functional pavement materials and characterization”

With the ever increasing demand for the riding quality and long service life of the pavement, more and more researches were focused on the functional pavement both in Europe and China. The Chair and Institute of Highway Engineering at the RWTH Aachen University in cooperation with the Southeast University and the Harbin Institute of Technology, China, launched the 3rd China-Europe Workshop on Functional Pavement in August 6-8, 2014, in Aachen, Germany.