Advanced Materials Research Vols. 919-921

Abstract: The road traffic safety measures decisions plays an increasingly prominent role not only in the road traffic management but also in the development of social economy. Combining the Changhong Road, Xiangyang, Hubei Province road traffic situation, the paper makes the road traffic safety measures decisions by using relational matrix analysis(RMA) and through the expected effect of the application of the RMA, this paper pointes out the practice significance of the application of RMA to the road traffic safety measures decisions.

Abstract: Influence of freeze-thaw cyclic on the durability of asphalt mixture with rubber particles was researched by experiment. Based on the typed AC-13 continuous dense graded aggregate, adding the amount of 1%~3% of rubber particles into graded aggregate, the splitting tensile strength and the void fraction of asphalt mixture with rubber particles under the condition of freeze-thaw cycle were measured. The test results show that the splitting tensile strength decreases and the void fraction increases with the increase of the number of freeze-thaw cycle. With the increase of rubber particle content, the splitting tensile strength decreases and the void fraction increases under the same number of freeze-thaw cycle. When rubber particles are added to graded aggregate, the splitting tensile strength of asphalt mixture is reduced to some extent. And when the rubber particle content attains 2%, the TSR (tensile strength ratio) achieves the optimal value.

Abstract: The loess test road of four highways in Shanxi Province selected. Through the contrast and analysis the data of resilient modulus and CBR on field, the paper presents the conversion relationship between resilient modulus and CBR for north and south shanxi province. The conversion relationships provide reliable basis for the resign of pavement construction. Keywords: subgrade soil; resilient modulus; CBR; correlation

Abstract: Waste soil progressing in shield tunnel construction should occupy large space, on the other hand, do harm to city environment. If the waste sand in silt and fine sand layer can be used as sand source of synchronous grouting, it will bring benefits for the enterprise and society. In indoor experiment, we select waste sand in different layers, sieved as sand source, then use the waste sand to produce slurry and compare their strength with the construction slurry’s. The study found, sieved waste sand in silt and fine sand layer can be used as sand source for making synchronous grouting slurry.

Abstract: Usually, foamed asphalt as cold recycling mixture binder, study on foamed asphalt warm mix technology was limited in China. Aimed at the asphalt foaming characteristic, the paper put forward the best asphalt foaming condition and carried out indoor and outdoor experiment to study the road performance of warm mixed asphalt mixture. The paper proposed the maturation curing time concept and its evaluation method. Results indicated that the warm mixed asphalt mixtures road performance can meet the HMA specification requirement in a lower temperature of construction, and low-temperature crack resistance was better than the tradition hot mix asphalt mixture so the warm mix foamed mixture has a remarkable economic and society benefit.

Abstract: Large track maintenance machine is one of the most important components of modernization of rail technical equipment. The sleeper supporting stiffness after large track maintenance operation has an effect on the safety and stability of train operation. This article make some conclusions through the analysis the influence of large track maintenance machine operation on sleeper supporting stiffness. It is indicated that during the maintenance operation, ballast compactness is enhanced and the supporting stiffness increases by tamping operation, but the supporting stiffness decreases due to the effect of stabilizing machine. After ballast cleaning operation, the supporting stiffness decreases to 10% of the original state, but back to 70%~110% of the original state after stabilizing operation. The influence of supporting stiffness on safety and stability of train operation should be taken into consideration in determining the allowable running speed after cleaning operation.

Abstract: Based on the multi-layer elastic system theory, large general used finite element software is used to analysis in the paper. The maximal shear stress SXY is analysed entirely by computing the structure layer bottom maximal shear stress SXY of the different combinations under the different axis load. The results show: the more the axis load, the more the shear stress SXY; the shear stress SXY decreases quickly along with the structure layer deep increasing; the relations between the basic layer rigidity and the shear stress are curve change laws.

Abstract: Tamping operation is an important part of railway maintenance work. The porosity of railway ballast is an important maintenance quality evaluation index during tamping process. In this paper, based on the discrete characteristics of railway ballast, the discrete element analysis model of railway ballast is created using the discrete element method, numerical simulations are performed to study the evolution of porosity of railway ballast under sleeper during tamping process. This paper focuses on the influence of vibration frequency of tamping tines during tamping process; an optimal vibration frequency is obtained from the simulation and compared with the actual vibration frequency recommended by China Railway Large Maintenance Machinery Co., Ltd. Kunming, it is found that the two vibration frequency is consistent. This result verifies that the discrete element method is an effective method to study the evolution of porosity of railway ballast during tamping process.

Abstract: Based on the essential characteristics of coal transportation network, the paper analyzed uncertainties of coal transportation network in 3 aspects ,structural uncertainty, time uncertainty and transport capacity uncertainty. It built a state equation of coal transportation network with the above three kinds of uncertainty, and established a robust control model of coal transportation network, to realize equilibrium and stability of coal flow in the coal transportation network. Finally, take Shanxi coal transportation network for example, to verify the accuracy and effectiveness of the coal transportation network robust control methods in the paper.

Abstract: Safe operation is the basic requirement of railway operation. Reasonable maintenance is the basic guarantee for the safe operation. Big data to analyze things as a rule of a cutting edge technology, applied to the analysis of railway detecting data processing, can improve the testing data of the use of the quality and efficiency of analysis. Based on big data, this paper points out state railway equipment management, reasonable status classification, solving the state transition probability, the prediction model is set up, providing better decision support for maintenance and repair work.