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Multiple Source Effect

The dialog Multiple Source Effect (Calculation menu) enables to evaluate different scenarios with respect to traffic noise impact by calculating the „effect related substitute level“ according to the VDI guideline 3722-2 3722-13.

Application to Facade Points and Building Evaluations

Applying the assessment requires facade levels calculated using building evaluations (see Building Evaluation) for road, railway and aircraft noise in separate variants (see Variants) for the evaluation parameters Lden and Lnight and the number of inhabitants per building (see Residential and non-residential Buildings). Depending on the selected calculation method, following results can be generated:

  • the „effect related substitute level“ at facade points and in the building evaluation symbols,
  • the parameters Annoyed Persons (AP), Highly annoyed Persons (HAP), Sleep disturbed (SD), Highly sleep disturbed persons (HSD), the statistical value of expectation of noise-induced myocardial infarction (NMI) and the number of IHD cases (ischaemic heart diseases) are written into string variables stored on the Memo-Window of each building.

Note

Industrial noise is neither included, nor assessed by the VDI guideline 3722-2 3722-13.

Application to the Grid and to Receivers acc. to VDI 3722

Basically, the evaluation according to VDI guideline 3722-2 in CadnaA does not refer to the grid or receiver points, since the number of persons AP/ HAP/SD/HSD is to be determined primarily.

In CadnaA, however, the „effect related substitute level“ can be calculated on the grid and at receivers as well. To this end, select the formula expression „f(x)“ from the „Evaluation Parameters“ tab (see Evaluation Parameters Tab) and via the double arrow (>>) from the parameter group „VDI 3722“ the evaluation parameters Lden (DEN) and Ln (Night).

Now, the „Evaluation Parameters“ tab may look like this:

Application acc. to EU 2020/367

Using this option, the number of ischaemic heart disease (IHD), the number of high annoyance (HA) and the number of high sleep disturbance (HSD) according to EU-2020 can be determined. If the "multiple source effect" is executed, the parameters are calculated for each building and stored in the memo field. To obtain the parameters for the entire project, the values need to be summed up in a second step using the ObjectScan, see Object-Scan (preset available).

Application acc. to DE 2020/367

  • nur verfügbar in deutsch -

Dialog options

Calculation Method

The following options are available:

  • VDI 3722: Calculation of the parameters Annoyed Persons (AP), Highly annoyed Persons (HAP), Sleep disturbed (SD) and Highly sleep disturbed persons (HSD) considering the noise impact of several sources types road, rail and/or aircraft noise, based on the VDI guideline 3722-2:2013.
  • VDI 3722 (A7, A8, A15, A16): With this option, the method according to the afore-mentioned edition of VDI 3722-2 is strictly applied using the inverse functions (A7), (A8), (A15) and (A16) mentioned there. As a mathematical error in these functions in VDI 3722-2 occurred an alternative method (i.e. the option „VDI 3722“) was implemented applying a numerically correct inversion of the original functions (A1), (A4) and (A9) and (A12). With regard to a possible revision of the guideline it is recommended, therefore, to use the option „VDI 3722“ instead.
  • HAP: The noise evaluation method according to Miedema MIEDEMA-2005 generates three indicators: Highly Annoyed Persons (HAP), highly sleep disturbed persons (HSD) and the statistical value of expectation of noise-induced myocardial infarction (NMI).
  • EU 2020 /367: With this selection, the number of IHD cases (ischaemic heart diseases) based on an incidence rate of 1.0, the number of highly annoyed persons (HAP) and highly sleep disturbed persons (HSD) is calculated and saved within the memo field of each building. For consideration of a deviating incidence rate in case of IHD and for summation of IHD/HAP/HSD, a template is available via Object Scan, see Object-Scan, Predefined. EU-2020

Assignment of Variants

Select for the noise types „Road“, „Railway“ and „Aircraft“ one of the available variants to be used for the assessment. This requires that for up to three noise types separate variants have to be enabled and calculated. By selecting „(none)“ the respective noise type is not included into the calculation. The variant assignment refers exclusively to the levels calculated in the respective variant (and does not take into account, for example, any variant-dependent number of inhabitants of the house).

Select in line „Save total in“ the target variant (that is, another „empty“ variant) to be used to display the „effect related substitution level“ at the facade points and on the building evaluation symbols. The calculation of the substitution levels for Lden is based on the fraction HA and for Ln the fraction HSD. Note that no levels <42 dB(A) can be mapped for the substitution level Lden.

Note

By selecting this variant and the evaluation parameters according to VDI 3722 (see Application to the Grid and to Receivers acc. to VDI 3722), the „effect related substitution levels“ are displayed both on the grid, at receivers and at facade points/building evaluation symbols.

Assignment of Evaluation Parameters

The noise evaluation method according to Miedema and the procedure in VDI 3722-2 refers to the levels Lden and Lnight. Assign using these list boxes which of the currently available evaluation parameters is linked to the two levels Lden and Lnight. In case Lden and Ln have been chosen as the first and the second evaluation parameter, no change is required.

Option "Detailed Results"

If this option is activated, the evaluation occurs for the different noise types individually as assigned by the variant and for total noise (e.g. HAProad, HAPrail, HAPair, HAPtot etc.).

Option "Protocol File"

With this option activated, the results of the HAP calculation are written into the specified text file. If necessary enter a file name and select the directory via the file selector symbol.

Button OK

Clicking this button starts the evaluation and writes the results into the Memo-Window of the buildings (and exported, with the option above selected).

Button „Export“

Via this button, the calculation results at the facade points are exported to a Shape file (ArcView *.shp). The geometry corresponds with the 3D-Shape-export of facade points (see ESRI Shape (*.shp)), but here the results for the various noise types are written to the following string variables (see dialog Memo-Window of the auxiliary polygons):

  • NAME, BLDG_ID: name and ID of the facade point (or BuildEval)
  • RES_RECV_N: number of residents at the facade point (assuming RES_RECV_N = EINW/(number of facade points)
  • evaluation parameters LP1 and LP2 for noise types R=road, RW=railway, A=aircraft (in dB)

Procedure

In the first step, the source type specific building noise maps are calculated.

In order to evaluate the grid and receivers as well, select the two VDI specific evaluation parameters on the „Evaluation Parameters“ tab (see above).

  • Select the Lden as evaluation parameter 1 and Ln as evaluation parameter 2 via menu Calculation|Configuration.
  • Assign roads, railways and air routes each to a single variant (e.g. using the short variant names ROAD, RAIL and AIR).
  • Define at least one further variant where the results of the multiple source effect calculation according to VDI 3722-2 are written to.
  • Enter a building evaluation symbol at some location and enter on the dialog part „Options“ the following values:
    • Height of Storey (m): 1000 (accord. to VDI 3722 just facade points at a single height are used)
    • Height Rcvr EG above Ground (m): 4

  • Close the dialog by OK.
  • Generate the building evaluation symbol for all buildings to be considered (via dialog Modify Objects, action „Generate Building Evaluation“).
  • Now, delete the initial building evaluation symbol used to specify the height settings.
  • Calculate the facade levels for all or the variants to be considered (via menu Calculation|Calc).
  • If necessary, start the grid calculation for all or selectable variants via the menu Grid|Calculate grid.

In the second step is the parameters describing the multiple source effect are calculated.

  • Open the dialog Multiple Source Effect on the Calculation menu.
  • Select the calculation method and address the variants to the source types.
  • Specify the variant the „effect related substitute level“ shall be written to.
  • Address the evaluation parameters and start the calculation with OK.

Example

Path: Examples\Configuration\VDI 3722-2

On the Memo-Window of the buildings the calculated values are displayed. These can be evaluated statistically using CadnaA specific procedures or in tables or can be presented as a map by spatial averaging using ObjectScan (see Object-Scan).

Dialog Memo-Window of a building with text variablesshowing resulting values according to VDI 3722-2