Analysis On The Axle Load Distribution Of Yunnan Expressways

This paper's research is a part of science and technology projects—"Asphalt Pavement Design Method for Fatigue Limit", in Yunnan Province. Recently, with the development of transportation, the highway construction in China has developed rapidly. Axle load is an important basic parameter for pavement design, which determines the pavement and road grade. In the cases of vehicle types increasing and overloading serious, the relatively accurate Axle Load Distribution and the effective method to obtain it are important guarantees for a reasonable highway design.In this paper, it researchs the expressway Axle Load Distribution in Yunnan Province. By analyzing charges of more than 30 toll stations of 3 expressways, by analyzing information of axle load surveys of six samples, the author obtains that the proportion of vehicles of Yunnan freeway; the Axle Load Distributions of typical freeway and the important parameters of distributions; the author obtains the equated number of equivalent axle load effect by using of the axle load distributions; the author calculates the effect of overload axle on pavement damage roughly.The way of using Axle Load Spectrum to describe the traffic load, can effectively avoid lots of errors when conversing Equivalent Axle Load, which come from many factors such as the difference of pavement type, the structure thickness, type of axle load, and forms of freeway damage. This way has a more comprehensive and objective description to the traffic load. In the USA latest pavement design, equivalent axle loads are replaced with the axle load spectrum and are used in pavement design. The study of axle load spectrum in this paper has the hope of providing a valuable reference for pavement design.