Applied Mechanics and Materials Vols. 744-746

Abstract: In order to automatically generate the railway Alignment, an alignment optimization method based on minimum cost is proposed. Firstly, an optimization model based on the coupling constraints of line-structure-environment is established, in which the comprehensive cost of engineering, operations, and the environment is considered as the objective function. Then based on the regular grids, the Geographic Information Data can be obtained and the comprehensive cost of the connection between two grids can be calculated. At last, the optimal connection between the grids is analyzed under the angle constraint and elevation constraint, thus the optimal alignment can be generated by the connection of grids.

Abstract: By combining RBF neural network with MIV algorithm, the main influencing factors of asphalt mixture pavement performance will be selected. First, the MIV values will be calculated by MIV method. Selection of variables is based on the size of MIV. There are 8 variables selected form 12 variables. Then, a new RBF neural network will be found by the data which have great impact to the output result. The comparison between the two RBF simulate results will prove that the method of MIV is feasible in variable selection. By the MIV method, the simulate results of RBF will be calculated faster and more accurately.

Abstract: Continuously Reinforced Concrete Pavement is smooth and almost needs not maintenance, which has long service life as well as a great potential application. Fiber reinforced polymer as a new type of composite materials with high strength, light weight, corrosion resistance and fatigue resistance which substitutes conventional steel rebars gives solutions to the problems caused by corrosion of reinforcement. In this paper, combined with the excellent properties of FRP rebars, FRP-CRCP is introduced in detail from structural response analysis, structure design, construction and the function of self-monitoring. Moreover, it is pointed out the problem of the design index and standard for FRP-CRCP that still needs further research.

Abstract: This paper first discusses the composition material of rubber asphalt and its control parameters, and then analyzes the experiment test method and criterion, then analyzed the gradation mix design method. The paper finally introduces the application of construction method of rubber asphalt in Chengdu 3rd Ring Rd.

Abstract: The Karakoram Highway (KKH), from Islamabad of Pakistan to Kasha of China, passed through the junction areas of the mountains of Karakoram, Himalaya and Hindu Kush and suffers serious destruction of different geo-hazards. This work analyzed distribution and characteristics of geo-hazards, including debris avalanches, rock falls, debris flows, landslides and flash flood along Khunjerab River from Sost to Khungerab and their destructions on KKH(K726~K821). These geo-hazards are commonly initiated by intensive rainfall and melting of glacier and snow, and numerously occurred, especially debris avalanches, rock falls and debris flows, to seriously destruct highway and frequently interrupt traffic. The destructions of highway mainly came from the burying of landslides, debris flows and debris avalanches, the scouring of debris flow and flash flood, the submerging of dammed lakes induced by debris flows and landslides as well as the breaking of rock falls. After analyzing the lessons and experience of geo-hazards mitigating and highway protecting since 1970s, the measures of hazards mitigating, including identifying potential hazard sites,controlling and disposing rock falls in time,integrated controlling debris avalanches, debris flows, landslides and flash flood, establishing emergency treatment plans for hazard chain and founding hazards alarming and highway safe protecting system, are strongly suggested for highway protecting and traffic security.

Abstract: In order to predict the durability of asphalt mixture under freeze-thaw cycles, the porosity and splitting strength of asphalt mixture under freeze-thaw cycle are studied, and GM(1, N) model in grey system theory is established. The results show that there is a good correlation between the porosity and the splitting strength in the durability factors of asphalt mixture. The value of the porosity increases with the increasing of the freeze-thaw times, and the value of the splitting strength decreased with the increasing of the freeze-thaw times. The GM(1, N) grey forecasting model can predict the porosity and the splitting strength well, and the calculated results agree well with the experimental data. Therefore, it is feasible to introduce the grey system theory in the prediction study of the durability of asphalt mixture.

Abstract: Two vehicle-track dynamics models on heavy haul railway are established in two conditions of rigid track and elastic track. And the impact of track elasticity on the wheel-rail dynamics performance was analyzed using models. The results show that the critical speed of heavy vehicles and wheel-rail dynamic indexes, such as wheel-rail lateral force and wheel-rail vertical force decreased on elastic track compared with rigid track. However, other dynamic indexes, including derailment coefficient and lateral displacement of wheelsets increased on elastic track. And the wheel-rail wear indexes are some differences on two tracks.

Abstract: The finite element calculation method was used and the principal stresses distribution in the asphalt pavement was analyzed. The damage index of the pavement structure is defined as asphalt pavement potential damage index(APPDI) based on the Drucker-Prager criterion, and the APPDI as the pavement structure damage index are applied. The results show that: (1) The most dangerous nodes of this example model appeared between rounds from the edge of round about 0 to 2cm and the place beneath the tire. The composition of the principal stresses are tensile and compression stress.(2) Failure modes are rutting and Bottom-up which are caused by tension-compression composite shear stress.

Abstract: In order to strengthen the normalization of the highway hydrology Zoning research work and improve the efficiency of Zoning, the analysis model of slope runoff intensity index was set up. The provincial highway hydrological Zoning index system was built to fully embody the relationship between highway engineering and hydrological factors. The research framework of provincial highway hydrology Zoning was established. The highway hydrology Zoning research framework and Zoning indices was taken as the guidance to divide Shandong province into 2 first-grade highway hydrological regions and 6 highway hydrological subregions which reflect the overall distribution of the highway hydrological conditions in the research region correctly. The corresponding descriptions were given to introduce the highway engineering characteristics of each partition.

Abstract: The coal gangue is one of the largest industrial solid waste emissions in our country at present, the research about making coal gangue as the filler to modify the properties of asphalt is still blank both at home and abroad. Using rotational viscosity test and dynamic shear rheological test (DSR) to study the high temperature rheological properties of the activated coal gangue modified asphalt binder when under the condition of different filler-bitumen ratio, and compared with mineral powder modified asphalt binder; Based on this, explores the mechanism of coal gangue modified asphalt binder. The results show that the activated coal gangue instead of mineral powder can make the high temperature performance of asphalt binder increases sharply. Research results provide feasible basis of activated coal gangue mineral powder can instead of mineral powder improving the high temperature rheological performance of asphalt binder.