Applied Mechanics and Materials Vols. 668-669

Abstract: The strain caused by concrete shrinkage and creep is separated through the field measurement data in this paper. Then D62 model and ACI model of finite element model is established to predict shrinkage and creep. Compared with the measured data, the feasibility and practicability of these two models can be proved.

Abstract: This paper deducing the analytical solution of temperature stress of reinforced concrete beams strengthened under the principle of compatibility of deformation. And we also analyze the influencing factors, such as elasticity modulus, thickness, coefficient of thermal expansion, the height of test beam, concrete mark and so on. The research shows that the elasticity modulus and thickness of the carbon fiber are the major influencing factors of temperature stress, the coefficient of thermal expansion and the height of test beam are the second influencing factors, and the influence of concrete mark is very tiny.

Abstract: To provide siltation state information for dredging of urban sewer network, an evaluation method of siltation state based on data collected through the Internet of things is proposed. We present a data acquisition program, and use the adaptive weighted fusion algorithm as a data preprocessing method. Based on Manning formula, an assessment model of siltation state is established. The experiment proves that this assessment model of siltation state is effective for sewer network.

Abstract: The main objective of this research is to explore the quantitative relationship between the pavement design parameters (structural layer thickness, voids, aggregate gradation and temperatures) and pavement performance parameters (rutting, cracking and IRI). The Mechanistic-Empirical Pavement Design Guide (MEPDG) was used and the analysis was performed on pavements under three temperature conditions namely the intermediate temperature zone (Zhengzhou in Henan Province), the low temperature zone (MOHE in Heilongjiang province) and the high temperature zone (Turpan in Xinjiang province). It was observed that 1) Pavement performances (rutting and cracking) were significantly impacted by layer thickness values until the values were larger than 14 inch; 2) Air void content influenced on not only predicted pavement rutting but also the thermal cracking.

Abstract: The main objective of this research is to investigate curling mechanism and moisture-density properties of c-type firming agent stabilized sludges. First of all, the chemical analysis was performed to determine the chemical constituents of untreated sludges from different regions of China. Then, microscopic analysis with the Scanning Electron Microcopy (SEM) and the Fourier Transform Infrared Spectroscopy (FTIR) was performed on botht the untreated and stabilized sluges. In order to evaluate effects of agents on stabilized sludges, the moisture-density tests were performed and testing results were analyzed. Through this study, the following conclusions were made: 1) SiO2 and Ai2O3 are their major constituents which take 70~90% of the total mass of a sludge; 2) addition of vermiculite or DK Powders could significantly improve performance of the stabilized sludges.

Abstract: The factors of combining horizontal and vertical curves are analyzed for guiding road design on expressway in practice and ensuring the safety and comfort of vehicle. The influences on drivers' by all kinds of flat vertical combination characteristics are researched. The necessary conditions meeting the horizontal and vertical combination rationality are proposed through the highway and driver characteristics. The identification sight on convex and concave vertical curve under driving at night and overpass are studied based on driver's sight guidance; the indexes of the vertical curve radius and length that my not meet horizontal including vertical combination are raised. Based on road surface drainage, the indexes that may not meet horizontal including vertical combination is proposed from the aspects of longitudinal slope, cross slope drainage and pavement structure. Comprehensive the design of flat vertical combination put forward the quantitative technical indicators that may not meet horizontal including vertical combination.

Abstract: Based on the analysis of setting principles of tidal lane, this paper describes the traffic and technical feasibility on setting tidal lane aat Xizhimen Outer Street between Chedaogou Bridge and Sijiqing Bridge, and then put forward a package on setting of tidal lane and control approaches of segment and endpoint. Through an analysis of the package, we expect to relieving road network pressure from tidal traffic and achieving the purpose of easing traffic congestion.

Abstract: The determination of the parameter set to be corrected is the premise and key of microscopic traffic simulation model’s calibration. In order to find out the sensitive parameter, this paper chooses Ronghua Road and Wing King Street intersection and the Shangdi Roundabout as experiments, and selects the queue length and travel time as the evaluation index, makes sensitivity analysis of calibrated parameters by microscopic traffic simulation software Vissim. It adopts a line chart method, range analysis and sensitivity coefficients to make comparative analysis of the evaluation results. At last, sensitivity parameters in intersection and roundabout are not identical.

Abstract: This paper introduced an optimization model to address dynamic speed control strategies for achieving network-wide speed harmonization. Genetic Algorithm (GA) was applied to search the optimal solution of the proposed model. During the search process, a computational fluid dynamics (CFD) based analytical model and microscopic traffic simulation VISSIM were applied to evaluate the performance of possible solutions. The proposed model can be used to determine the deployment of dynamic speed limits, the displayed speed limit, and the timing to change these speed limits. The proposed model was tested using VISSIM in an urban freeway network of about 12 miles long. Different simulation scenarios with varying AADT from 60,000 to 12,000 were tested. It was found that when properly implemented, dynamic speed control can improve traffic flow conditions, reduce congestion and emission, and enhance network throughput. For example, in the selected urban freeway network with the AADT of 80,000, the proposed dynamic speed control strategy can save 5% average travel time, reduce 9% of the vehicles with high collision risk and about 11% emission.

Abstract: According to persistence of vision and the principle of color overlay, a new painting method of anti-dazzle panel is proposed. This painting method could allow drivers to see different colors under different speeds, which could be a means to inform drivers of their speeds. First the research analyzes the time of persistence of vision and the process of color overlay; then establishing the relationship between travel speed and color overlay based on persistence of vision; at last, using animation to simulating the method proposed in the research and illustrating the feasibility of this method.