Advanced Materials Research Vols. 446-449

Abstract: The number of traffic accidents caused by ice and snow is generally three to four times higher than that in normal condition. In order to improve safety level when driving on ice and snow pavement, adhesion coefficient is a vital parameter need to be analyzed. The relations between adhesion coefficient and temperature, relative humidity, snow’s thickness, snow’s compactness were studied. And their relation models were established. These models may provide the basis for the road administration department to conduct traffic control decision-making according to the weather condition and the state of ice and snow.

Abstract: Research on cooperative working performance of cold-formed steel stud wall(CFSW) and steel frame(SF) was carried out by analytical method and finite element method. The practical calculation methods of shear force and horizontal displacement for CFSW - SF structure under horizontal load were presented. The superposition principle between CFSW and SF in elastic stage was verified in terms of strength and stiffness. The investigation by FEM indicates that the shear force distribution in elastic stage is in accord with lateral stiffness of CFSW and SF, the shear force distribution rate of CFSW declines along with the increasing of horizontal displacement while thar of SF increases because lateral stiffness of SF degenerates more slowly than that of CFSW.

Abstract: The noise data results from two aspects, technically, different mobile phones traveling on different roads may generate the same handover sequence; operationally, signal error in mobile communication network possibly causes wrong handover information. Second, four types of noise data are summarized, that is wrong sample data from signal error, passenger cell phone sample noise data beside roads, vehicle cell phone sample ones between parallel and overlapping roads. Third, hierarchy and K means cluster algorithms are applied with SPSS software for the collected sample data cleaning based on real handover data by try and trial to produce link travel speed, which is compared with practical traffic situation. Finally, historic loop data is used as the baseline to evaluate the accuracy compared with cleaned results.

Abstract: To evaluate the capacity of urban road section with damaged pavement accurately, it is necessary to evaluate on damaged pavement and study the quantified affects of damaged pavement on the capacity of road. In this paper, pot hole’s width, rut depth, crack ratio and repair ratio were used as the evaluation indicators of the of pavement’s status, the evaluation method of damaged pavement through gray cluster analysis was given. The surveyed damaged pavement sections are classified through this method. The definition of damaged pavement correction coefficient is given, using gradual approach method to decrease damaged pavement correction coefficient till the error of capacity of road section is lower than admissible error, the damaged pavement correction coefficients of different levels of damaged pavement were obtained based on the parameter that surveyed on different level of damaged pavement sections.

Abstract: The original plan is to use vibro-stone column composite foundation to treat a large oil tank foundation. The result of strengthening is not satisfactory because of some factors, such as difficulty to control quality and long construction period etc. Treated ground can not meet the design requirements. The key in treatment design of tank foundation lies in bearing capacity and deformation of foundation, especially in non-uniform deformation. Through the analysis of site conditions, composite foundation of CFG piles is adopted. It is designed according to strength and deformation of dual control theory. Experimental results show that the compound used in foundation design is appropriate.

Abstract: In this article, the three-dimensional finite element method was used to analyse the composite base asphalt pavement structure life, which setting the graded gravel layer between the asphalt surface layer and the semi-rigid base layer. The main effect considering on the service life were the face layer thickness, the graded gravel thickness ,the contact state and so on, and compared the compound base with typical semi-rigid base the service life of the asphalt pavement . The analysis shown that the road surface contact state was the biggest influence to the service life. When using reasonable pavement structure combination, composite base asphalt pavement generally wouldn't produce the service life of the decline .

Abstract: There are great difference in traffic flow characteristics between snowy pavement and non-snowy pavement. Ten road sections were investigated and the data of traffic volume, headway, speed and density on snowy and non-snowy pavement were collected. Vehicle’s arrival rules were compared and reasonable distribution was given. The relation between traffic volume and speed, density and traffic volume were compared between snowy pavement and non-snowy pavement. It indicated that negative binominal distribution is more fit to vehicle’s arrival frequency on snowy pavement. Speed decreases for the same traffic volume and traffic volume decreases for the same density on snowy pavement.

Abstract: In order to research the temperature-dropping characteristics of warm mix and hot mix asphalt, some rutting test panels are used as specimens to determine the temperature-dropping characteristics of hot mix asphalt（HMA）, warm mix asphalt（WMA） with mixing additive “LuBo” and warm mix asphalt with mixing additive “Sasobit” under the conditions with initial temperatures of 110°C and 130°C. The test results indicate that：the higher initial temperature，the higher temperature-dropping rate is. After 25min the temperatures of rutting test panels with initial temperatures of 110°C and 130°C are close to 66°C and 68°C. The temperature-dropping rates of different types of mixtures are not the same. When the initial temperature is 110°C, the temperature-dropping rate of hot mix asphalt is the highest, the temperature-dropping rate of warm mix asphalt added with “Sasobit” is in the middle, and the temperature-dropping rate of warm mix asphalt added with “LuBo” is the lowest. After 35min, the temperatures of the three types of asphalt mixtures had fallen by 53°C， 51°C and 49°C separately.

Abstract: The characteristics of the transmission matrix of the absorption material of the automotive body are researched in this paper. According to these characteristics, the calculation result is right which is proved that the theory method is right.

Abstract: When two lines with 20 same high-speed passenger vehicles are traveling on the 40 m+4×72 m+40 m party pre-stressed concrete continuous box-girder bridge from both ends, this bridge vertical load-carrying frequency is calculated with the vehicle-bridge system mode1. When the vehicle parameters, such as the unsprung mass of each wheel-set of the vehicle, the suspension spring stiffness, the vehicle length and the mass of the vehicle, are changed, the bridge vertical load-carrying frequencies are changed too. But when the train speed is changed, the bridge vertical load-carrying frequencies aren’t changed. It is shown that the bridge vertical load-carrying frequency is the vehicle-bridge system natural frequency, it is only depend on its natural parameters.