Barrier

Barrier objects contain settings that affect the calculation of shielding and diffraction effects of barriers.

Train Noise Expert includes the ability to consider simple trackside barriers in sound pressure level predictions. A maximum number of two Barriers may be specified; one each side of the track. Barriers are shown in the 3D model view, but not the 2D model view.

Barrier objects are considered part of an Environment object. Thus, when changing between different environment objects, the Barrier configurations may also change. A Barrier object can be added to the environment item in the model view by right-clicking on the environment item and selecting ‘Add barrier’:

Calculation

Train Noise Expert includes the effect of noise barriers by applying a calculated insertion loss to the calculated sound pressure levels.

The current barrier insertion loss calculation follows the Maekawa method. The influence of ground reflections on both sides of the barrier are included (summed incoherently). Barrier reflections are not accounted for in the current implementation, therefore barrier insertion loss may be slightly over-predicted.

Input Parameters

Name	Data type	Unit	Comment
Label	Text	-	A label for this Barrier. Special characters are not allowed.
Distance from track centre	Number	m	The horizontal distance between the centre of the Track and the Barrier. Positive values are towards the left from the perspective of a forward travelling train.
Top height above rail	Number	m	The vertical distance between the top of the rail and the top of the Barrier.
Library item	Lib. item	-	The library item for the Barrier.
Barrier type	Choice	-	The type of barrier to be used in the calculations. For the moment, the only option is ‘simple’, which is a thin and infinitely long absorbent barrier. Further barrier types may be added in the future.