HJ 2.4 (2021)
Version of HJ 2.4
CadnaA allows the calculation according to chapter B3.1 and B3.2 of version 2021 HJ24-2021. Version 2009 does not include railway noise.
Calc teq,i according to B.18
With activated checkbox, the equivalent passing time is calculated according to B.18 of HJ24-2021 instead of B.17. For further information, see HJ 2.4 (2021), chapter B.3.1.
Aground spectral (according to GB/T 17247.2)
With activated checkbox, the ground attenuation is calculated according to GB/T 17247.2 instead of formula A.20 of HJ24-2021. For the calculation of ground attenuation, the frequency of 500 Hz is used. For further information, see HJ 2.4 (2021), chapter A.3.3.
2D distance for hm
Barrier attenuation
Calculation of Foliage and Housing
The calculation of attenuation due to housing is handled as described in ISO 9613-2 ISO-9613-2-1996. To consider housing, the respective object needs to be entered, see Built-Up Areas and Foliage.
The calculation of foliage is not considered for HJ 2.4 (2021), see also formula B.19 of HJ24-2021.
Protocol
The calculation protocol (see Calculation Protocol) should only be used for railway objects containing one line in the train list of the railway object. For further information, see HJ 2.4 (2021), Local Train List.
Limitations
Following sections of HJ24-2021 are not implemented in CadnaA:
- Calculation of stationary sources Cf,i and Cf,θ according to chapter B.3.1
- Multiple reflection on sound barriers and consideration of noise reduction coefficient (NRC) according to chapter B.3.1