Tian Xiao

Dynamic Response Analysis of Cement Concrete Pavement under Different Vehicle Speeds

Through a finite-element model developed in the ANSYS (engineering simulation software) platform, the stress-strain properties of concrete pavement under dynamic loads were studied and the affecting laws of different speeds on the stress-strain properties of concrete pavement were determined in this paper. Analysis results indicate the significant difference between static loads and dynamic loads on concrete pavement performance and deterioration. Vehicle speed has a significant effect on the stress-strain properties of concrete pavement. Furthermore, slower vehicle speed has a greater effect than faster vehicle speed. This research finding can provide a more accurate grasp of the actual working conditions of concrete pavement, and provide some guidance to the structural design of concrete pavements.

Analysis on the Anti-Glare Plate Setting Distance on Horizontal Curve Sections of Expressway

Glare is one of the most important factors threating expressway traffic safety an night. The most commonly way to prevent glaring night is to set anti-glare plate. Different from the straight sections of expressway, the relationship between the front light of vehicles and the distance of anti-glare plate on the horizontal curved section has some-what changed. Through a lot of tests and finite element simulation, the relationship between the distance of anti-glare plate, horizontal curve radius and anti-glare effect were analyzed systematically. Distance calculation formula of anti-glare plate in horizontal curve sections was revised in this paper. The anti-glare plate distance requirement under different expressway alignment design indexes and its calculation formula was proposed. The achievement was beneficial to confirm the anti-glare effect and improve traffic safety. It can provide us with a reference and a supplement of the specification.

Mechanical Response Analysis of Heavy Traffic on Semi-Rigid Base Pavement Performance

Viewing so many overload vehicles, this paper analyzes the stress distribution of asphalt pavement structure under heavy traffic theoretically, according to the main asphalt pavement structure form in our country. By using elastic layer theory and BISAR3.0 program, analyzed the mechanical response variation of semi-rigid base asphalt pavement under different axle loads. The results showed that the mechanical response and the stress indexes of pavement structure under heavy traffic changed significantly. Therefore, in asphalt pavement design, the impact of heavy traffic should be fully considered and we must take measures to control the overload situation.

Impact of Subgrade Resilience Modulus on Heavy Load Asphalt Pavement Mechanical Properties

Subgrade resilience modulus is an important mechanical parameter in pavement design. It will directly influence the design result of pavement structure. Using BISAR3 of SHELL design method, the impacts of subgrade resilience modulus on pavement surface deflection, base and subbase bottom tensile stress, surface layer bottom tensile stress of the heavy load asphalt pavement structure were analyzed. And the influencing laws were analyzed, too. The results show that the mechanical and deforming characteristics of heavy load asphalt pavement were influnced significantly by subgrade resilience modulus. With the increasing of subgrade resilience modulus, the pavement surface deflection, base bottom tensile stress would significantly decrease, and fatigue life would be improved.

Impact of Structural Course Thickness on Heavy Load Semi-Rigid Asphalt Pavement Service Life

Calculation of structural course thickness is the primary task in pavement design. It will directly influence the mechanical properties, service life and the cost of pavement structure. Using BISAR3 of SHELL design method, the impacts of structural course thickness on the mechanical properties and service life of heavy load semi-rigid asphalt pavement structure were analyzed systematically. And the influencing laws of the thickness of surface course, base course and sub-base course on heavy load semi-rigid asphalt pavement service life were also discussed. According to the results of sensitivity analysis of structural course thickness and axle loads, a prediction model of service life of heavy load semi-rigid asphalt pavement was proposed. These achievements can contribute to determine the rational structural course thickness of semi-rigid asphalt pavement and ensure the service life of pavement consistent with the cost.

Effect of Asphalt Layer Modulus on the Mechanical Properties and Service Life of Heavy Load Semi-Rigid Asphalt Pavement

Asphalt layer modulus is one of the important mechanical parameters in pavement design. It will directly influence the design result and the mechanical properties of asphalt pavement structure. Using pavement design and analysis software, the effects of asphalt layer modulus on surface deflection, tensile stress at the bottom of base and sub-base course, stress at the the bottom of asphalt layer and service life of heavy load semi-rigid asphalt pavement structure were analyzed systematically. And the influencing laws were analyzed, too. The results indicate that the mechanical properties, deforming characteristics and service life of heavy load asphalt pavement were influnced significantly by asphalt layer modulus. With the increasing of asphalt layer modulus, the surface deflection, tensile stress at the bottom of base and sub-base course would significantly decrease, and service life of heavy load semi-rigid asphalt pavement structure would be improved.