engleski

The impact of ballast depth on vertical track stability

The main elements of the superstructure of the classical rail track constructions are the rails, sleepers and the ballast bed. The connection of the rails and the sleepers is achieved by an appropriate method of fastening. If the rail track ballast is observed, its main purpose is to elastically and equally transfer the loads caused by the rail vehicles to the plane of the lower structure, to secure the direction and height of the rail track and to dampen the vibrations in the rail track. For the ballast to fulfil the mentioned requirements, it must have sufficient dimensions (width and thickness) and must be made out of good quality material. This paper considers impact of the ballast thickness on the vertical stability of the rail track. The measurements of track displacement were performed on the Croatian Railways network (location: Skrljevo – Meja – Pecine). This section is in a cut with longitudinal slope of 22 ‰ and thickness of the ballast is 15 to 20 cm. During the year 2005 the wooden sleepers were replaced with the concrete sleepers. Two years after the replacement, new sleepers sunk due to further crushing of the ballast. Due to subsequent crushing, the crushed stones lost their sharp edged form, which in turn led to reduction of mutual wedging of the granules, which finally led to settlement of the sleepers.

ballast track; ballast crushing; track stability

nije evidentirano