Applied Mechanics and Materials Vols. 178-181

Abstract: This paper focuses on the problem of serious deviation about predicted traffic flow on the feasibility study stage of expressway,puts forward an idea to compare and analyse the predicted traffic flow in feasibility study stage and the actual traffic after project operation,introducts least square method model, and finds out the linear relationship between them, thus predicts traffic flow of expressway operation. Finally, the calculation is made by combining with concrete expressway project,which proves that this method is usefull to improving the accuracy of the traffic flow forecast.

Abstract: Composite pavement consisted of flexible asphalt surface overlay and rigid concrete base layer has come up. Though it occupies advantages of asphalt and concrete pavements, still there are problems containing thermal cracking, rutting deformation and pothole which result from the out-sync shrinkage of temperature. Therefore, influence of temperature on the composite pavement structure has been analyzed with methods of theoretical analysis and numerical simulation. And results indicate that the thickness of asphalt layer in some sense determines the influence extent of temperature and worst case happens at the concrete joints, which means that the optimal asphalt (Here, the best choice of asphalt thickness equals 16cm) and suitable joints should be designed.

Abstract: The ultraviolet aging of asphalt and asphalt mixture has attracted attention worldwide from research progress and testing methods. The research progress and testing methods of ultraviolet aging of asphalt are described in this paper. Author also briefly discussed the methods for improving anti-aging properties of asphalt and asphalt mixture.

Abstract: This article describes and analyses the rutting forming process, basic classification, and control standard of the rutting depth, and the results show that, Understanding of the fundamental characteristics of the rut and mastering of the rut control standards, is an important reference index which is used to design the asphalt pavement structure and materials

Abstract: Through the analysis of ecological protection for slope protection in mountainous area expressway,it illustrated the ecological protection technique advantage and mechanism.A new ecological protection technique is put forward,which is vegetation blanket protection technique.This ecology protection method was applied in the Lu'an-Qianshan Expressway and proved effective. The feasibility of protective measures was analyzed. Which provide a new ecology protection way to the expressway slope, which is in inferior land and rock area.Its protection mechanism and design principle is discussed in this paper.

Abstract: In this paper, the caustics method was used to explore the distribution of contact forces inside a packing of discrete square cells submitted to a compressive load. The self making subroutine 3-D generation algorithm about irregular particle generation and particle contact interface generation were adopted, and irregular particles were randomly generated in the designated categories with this algorithm. The vibration compacting load diffuse and transfer law with different media dense state were analyzed. The test results show that the vibration load caused the effective compaction region was changed vertical long axis oval into the level long axis oval. The study provides an idea to research and employs a new over-loading road which better repels tired retrogression under the dynamic load.

Abstract: The thermal infrared (TIR) radiation in the deformation and progressive failure of coal roadway and the mechanism of thermo-mechanical coupling were investigated. The experimental achievements showed that the surface TIR temperature (TIRT) rose non-uniformly with the load increase before the stress peak and TIR radiation caused by stress concentration and fracture belt, was much stronger and higher than that caused by stress relaxation, week friction and tensile fracturing. The progressive failure zones were determined from the change ratios of TIR temperature of the different areas of the surrounding rocks. The infrared thermal image anomaly appeared with the macro-cracks development in the progressive failure of roadways, which reflected the spatial and temporal features of infrared precursor respectively. The infrared thermal image precursors were classified as TIRT increment region and TIRT constant region to disclosure the damage evolution and localization behaviors of roadways.

Abstract: Asphalt pavement of water damage is a major form of our country highway asphalt pavement damage, the paper analyzes pavement structure internal water source, water damage of asphalt pavement of the influence factors, through the determination of the three indexes and asphalt of asphalt mixture splitting tensile strength, water erosion proof of asphalt mixture and its influence, and put forward the corresponding prevention and control measures to improve the pavement performance and extend the service life of road surface has important practical value.

Abstract: It is necessary to suppress harmonics because of electric railway traction power supply system has serious harmonic problems. This paper has established averaging model, and the robustness of active power filter is analyzed based on the H-infinity control theory. Simulation results show that electrified railway harmonic control effect is good based on H-infinity control. And it has the fairly good stability and robustness.

Abstract: The application of waste tire rubber in highway engineering mainly focuses on the modification of asphalt rather than the asphalt mixture, which restricts the application of waste tire. The addition of rubber has an effect on the performance of the mixture because of the obvious difference between rubber and mineral aggregates. This paper makes a research on the preparation technology of the specimens made of crumb rubber modified asphalt mixture in the laboratory by means of the study of selection of rubber、aggregate gradation、compaction temperature and so on. The effect of compaction was investigated in terms of the air void of the specimens under different preparation conditions. The optimal preparation process of rubberized asphalt mixture is put forward which could be proved to effectively control the pavement damages such as loose、stripping and so on.