A survey study for axle Load Distribution of Full-trailer Trucks with Tandem Steering Axles-in Iraq

In Iraq, As a result of the continuous development in the manufacture of heavy vehicles in terms of the distribution of axle and their number and what it contains of the impact on the pavement, there is a need to study the distribution of axle loads of new types of vehicles type full-trailer truck. This study included the distribution of axle loads of the two new types of full-trailer truck with tandem steering axles. The study is based on an axle load survey for the two types of vehicles covered by this study. This survey was carried out in Kerbala and Hilla cities during 2016 and covered 89 full-trailer trucks type 11.2+2.2 and 11.22+2.22. By using the results of the axle load survey, the distribution of axle loads of the trucks type 11.2+2.2 and 11.22+2.22 was obtained. The maximum axle loads obtained from the axle load survey were 12.320, 21.990, 28.320 and 34.580 tonnes for front single, front tandem, rear single, and rear tandem axles respectively. The results of this work allowed the conclusion that there is a serious overloading problem of the tandem steering axle as well as each other types of axles of the above vehicle types are covered in this study. This paper showed the urgent need for a legal axle load limit for tandem steering axle load in Iraq and recommends the activation of the enforcement system on the axle load limits on Iraqi highways.