The field study and numerical simulation of industrial noise mapping

Journal of Building Engineering 9 (2017) 60–75

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Journal of Building Engineering journal homepage: www.elsevier.com/locate/jobe

The field study and numerical simulation of industrial noise mapping ⁎

Tarık Serhat Bozkurt , Sevtap Yılmaz Demirkale

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Istanbul Technical University, Department of Architecture, Turkey

A R T I C L E I N F O

A BS T RAC T

Keywords: Industrial noise mapping Healthy environment Noise limit levels Sound barrier Sensitivity analysis

The acoustic environment is known to have a physiological as well as psychological impact on human health and also have a great importance in the establishment of comfort conditions. Accordingly, a healthy environment and better quality of life depend on environmental noise control. There are numerous research about traffic, airport and railway noise mapping studies with related to the subject in the literature. However, there are some other factors affect the outcomes of the noise mapping studies such as how the industrial buildings is used. Although this factor effects significantly the industrial noise mapping studies, there is no sufficient number of research studies refers this topic. In fact, the research studies about the noise level of industrial units and their interaction between its surrounding areas play a key role on the industrial noise mapping. It is a well-known fact that there are too many parameters effect the noise mapping results in the real world applications. On the contrary, in the local areas such as an industrial estate, some parameters can be more effective on the noise level and may need a special attention in order to obtain noise mapping results accurately. This study deals with the issue of industrial noise mapping process as part of ensuring environmental noise control and demonstrates that there is a strong relation between the noise level of an industrial estate and the usage of the industrial buildings. In order to achieve this purpose, numerical analysis and some field researches were carried out in the study. In this scope, the sound levels of industrial noise sources were determined and – on the basis of the prevailing sound propagation conditions – a noise map was established for the region. For the industrial noise map, the limit values published in the Turkish Environmental Noise Regulation were used, and the number of people affected by excessive noise levels determined. Noise barriers were designed and their impact on reducing excessive noise in populated areas to acceptable limit values were evaluated. It is concluded that the industrial noise mapping research systematically carried out in order to show the role of the sensitivity analysis related to the different opening of the doors of the industrial buildings.

1. Introductıon Environmental noise control has a great importance in human life. Literature researches reveals that environmental noise can affect public health significantly and has a remarkable influence on the human activities [1–4]. Especially, WHO (World Health Organization) mentions that environmental noise affects hypertension, cardiovascular risks and sleep disturbance [5,6]. In this regard, noise mapping is necessary to ensure environmental noise control. Noise maps are established to obtain information for noise reduction planning. For this purpose the sound levels in the area of interest are determined and the areas affected by excessive noise identified. Noise maps are needed in order to ensure acoustic comfort conditions in connection with the development of residential areas, industrial areas and transport axes in urban areas. Besides those major zoning decisions, they are also useful when determining the minimal sound insulation of individual buildings necessary for acoustic comfort conditions [7]. ⁎

In the scientific researches, noise mapping studies are generally performed in the area of traffic,airport and railway noise mapping. In addition, these studies are generally carried out using noise mapping simulation programme and also, noise mapping simulation programmes generally give reliable results for large areas [8–17]. In fact, there are not too many scientific research mainly focused on industrial noise mapping based on sensitivity analysis related to the different opening of the doors of the industrial buildings. In Europe, industrial noise mapping and outdoor sound propagation model studies are carried out according to the EU Environmental Noise Directive (2002/49/EC). When the studies about industrial noise mapping is examined in the literature, It can be easily recognized that the industrial noise mapping studies has been generally carried out in Germany (Berlin), Northern Ireland (Belfast), Romania (Bucharest), Turkey (Bursa), Portugal and other European countries [7,18–22]. The main subject of this study is to perform a systematic research on the industrial noise mapping in order to show the importance of the

Corresponding author. E-mail address: [email protected] (T.S. Bozkurt).

http://dx.doi.org/10.1016/j.jobe.2016.11.007 Received 24 July 2016; Received in revised form 31 October 2016; Accepted 9 November 2016 Available online 19 November 2016 2352-7102/ © 2016 Elsevier Ltd. All rights reserved.

Journal of Building Engineering 9 (2017) 60–75

T.S. Bozkurt, S.Y. Demirkale

SoundPLAN noise mapping programme ISO-9613-2 was used as applicable standard as defined in the Turkish Environmental Noise Regulation, and Lden (day–evening–night equivalent sound level) was set as evaluation method. These parameters define the noise scale and determine the number of persons affected by noise. The altitude readings of the maps in the AutoCAD format were input into SoundPLAN and a digital terrain model (DTM) was obtained which was used to establish a digital topographic model of the area. Then residential and industrial units were transferred from AutoCAD into the model and storey heights assigned to obtain a three-dimensional model (Fig. 1). For the storey heights the data in the municipal maps were used as basis. They were compared with field data and corrected accordingly. To obtain population data for the study area, the communal officer – responsible for the area was contacted. The data were also entered into the simulation programme. The following systematic was applied in the assignment of the relevant data of individual industrial units in the established threedimensional model. In Table 2, a list of internal sound source data has been depicted. This list of data has been selected from database about internal sound sources in which standardized by SoundPLAN. Based on field research, an internal sound source type was defined for every single industrial unit (Each industrial building interior function type was obtained from information received from industrial site staff and supported with field observations.). The source type was selected among the range of source types available in SoundPLAN; the type most closely resembling the observed type was chosen (Table 2, selected source type in SoundPLAN for industrial units). After the source type definition their performance ratios (in percent) were entered; they vary in accordance with working hours (Performance ratios means “each industrial unit's internal noise source performance ratio (as percentiles)”). Performance ratio data were obtained through field research (Performance ratio data type was obtained from information received from industrial site staff and supported with field observations). The following performance levels were found: 100% between 8 am and 7 pm, 20% between 7 pm and midnight, and 10% between midnight and 8 am. The data were entered into the model and their respective emission type was defined. After having entered the performance data of the respective internal noise data of the industrial units, detailed system information was defined in order to determine the sound insulation value Rw of the buildings’ lateral envelopes (Methodology of calculation of sound insulation value is detailed in Section 2.2.2). For this purpose all openings in the lateral building envelopes, doors, windows, etc., were modelled, and the respective envelope materials assigned to every single side of every industrial unit. Finally, all envelopes were defined as plane source. With these parameters the industrial building modelling was completed (Fig. 2). Temperature, humidity and the Cmet values were entered into the calculation which was based on standard ISO 9613-2 (Cmet: meteorological correction, as detailed in the next paragraph). With this approach the long-term noise contours of the noise map were obtained. The noise levels for Lden, Lday, Lnight and Levening were calculated and the number of persons living in areas of above-limit noise levels were determined. The meteorological correction (Cmet) is used to obtain a long term average A-weighted sound pressure level, where the period is several months. A value in decibels for Cmet is calculated using the term C0 (a factor in decibels which depends on local meteorological statistics for wind speed and direction, and temperature gradients) multiplied by terms including the height of both source and receiver the distance between them as shown below: [39]

sensitivity analysis in usage of industrial units. For this propose, this research deals with the establishment of an industrial noise map for the Des industrial estate, located in the district of Ümraniye / Istanbul, and it's near surroundings. Approximately, 140 active industrial building and 1200 residential building is located in the study area. In Des industrial estate and it's immediate vicinity, industrial companies generally performs metal production activities. These metal production activities can be listed as foundry, turning lathe, cutting and bending metal sheets, metal stamping, metal cutting, metal welding, steel pipe manufacturing, metal workshop and etc. The industrial estate comprises manufacturing enterprises with high noise generation which affect the settlement areas in their immediate vicinity. People in the area suffer from hearing and perception problems, and noise-related physiological and psychological effects are undeniable [18]. In the course of this study industrial noise maps were prepared for different conditions, the main sources and affected areas were identified and noise barriers were designed to reduce the noise problem to manageable levels. 2. Methodology 2.1. Noıse control regulations As in the case of the European countries, Turkey has enacted a number of laws designed to regulate noise. Their direct or indirect purpose is to ensure acoustic comfort conditions. In this connection, the Turkish Environmental Noise Regulation has defined noise limits for industrial areas (Table 1). 2.2. Procedure and method 2.2.1. Modellıng process The outdoor sound propagation mechanism plays a crucial role on the determination of the interaction factors between sound sources and receivers. Specifically, it deals with the propagation path from source to receiver. In the propagation path from source to receiver, the interaction factors are attenuation account for spherical spreading (Adiv), ground absorption (Agr), diffraction by barriers (Abar), atmospheric absorption (Aatm), attenuation from intervening vegetation and other parameters. This interaction factors affect sound energy lost in free field sound propagation [24–34]. In this study, all of the interaction factors between sound sources and receiver (Adiv, Agr, Abar, Aatm and other parameters) were taken into account to generate industrial noise maps. SoundPLAN simulation programme [35] was used in this numerical study. European Commission Working Group Assessment of Exposure to Noise (WG-AEN) prepared Good Practice Guide for Strategic Noise Mapping and the Production of Associated Data on Noise Exposure [36]. In this project, this good practice guide was used in model input data process. A 4 km2 large study area including the industrial estate and it's immediate vicinity was defined. 1:5000 and 1:1000 scale maps in the NetCAD programme format [37] were obtained from Ümraniye municipality and transferred into the AutoCAD format [38]. In the Table 1 Environmental Noise Assessment and Management Direction Noise limit values for industrial areas in Turkey (Published by Ministry ofEnvironmentand Forestry inTurkey) [23]. Area

Lday (dBA)

Levening (dBA)

Lnight (dBA)

In mixed commercial and noisesensitive areas locations with a high density of residential buildings

65

60

55

C met = C 0 [1 − 10(hs +h r ))/d p] (dB)if d p >10(hs +h r )C met = 0(dB)if 10 (h s +h r ) ≥ d p 61

(1)

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Fig. 1. SoundPLAN model and aerial photo of the industrial estate [18].

Therefore, it must be clearly presented the methodology of calculation of Rw at SoundPLAN software. Rw is usually the sound insulation coefficient of a facade element. To have the sound insulation of the facade, it is used to ISO 140-5 standard (revised as ISO 16283-3:2016). For in situ measurements of existing buildings, the ISO 140-4:1998 (revised as ISO 16283-1:2014) standard presents the following definition of the sound insulation index, which will be used to characterize the measurements and simulations presented in this research. Standardized Level Difference (DnT) in which the reverberation time of the environment where the sound is received, is related to the reverberation time of reference [40,41].

Table 2 Selected source type in SoundPLAN for industrial units (The internal sound source data type about each industrial units has been selected from SoundPLAN software in accordance with building interior function type. Interior function type of each industrial building obtained from information received from industrial site staff and supported with field observations.) [18]. Type Of Source For Industrial Units

Sound Power Level (dBA)

Metal Workshop Steel Plates Factory Steel Pipe Manufacturing Turning Lathe Steel Moulds Manufacturing Foundry

105,1 91 95,7 85,2 88,3 97,5

DnT =(L1−L 2 )+10lg ( where

T )(dB) T0

(2)

where

hs is the source height; hr is the receiver height; dp is distance between source and receiver projected to the horizontal ground plane; As stated in ISO 9613-2 ‘Experience indicates that values of C0 in practice are limited to range from zero to approximately +5 dB, and values in excess of 2 dB are exceptional. Therefore only very elementary statistics of local meteorology are needed for ± 1 dB accuracy’ [24,39]

L1 is the sound pressure level at the acoustic emission site (dB); L2 is the sound pressure level in the receiving room (dB); T is the reverberation time of the receiving room (s); T0 is the reverberation time of reference (T0=0.5 s). The apparent sound reduction index is evaluated using bellow formula. [40,41]

S R′ = (L1−L 2 )+10lg ( )(dB) A

(3)

where

2.2.2. Methodology of calculation of sound insulation value The Rw value is the acoustic insulation coefficient, weighted frequency, and plays a key role in the results presented in this paper.

L1 is the sound pressure level at the acoustic emission site (dB);

Fig. 2. Modelling process of the industrial units (At first the internal sound source emission type was defined, then the acoustic insulation values Rw of the building envelopes were calculated on the basis of information about the individual building facades, and finally all facades were defined as plane source) [18].

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Table 3 Industrial noise map result data (Values calculated by Sound PLAN Software to Rw (the sound insulation value) for each situation investigated in this study) [18]. Condition (Industrial Units Working Condition)

Time Period

SoundPLAN Noise Mapping Simulation Programme Results

Maximum Value (According to Turkish Environmental Noise Assessment and Management Direction)

The total number of people affected by noise when noise levels are higher than the limit value

The ratio of people affected by noise when noise levels are higher than the limit value

All Doors of The Industrial Units Open

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

3555 3326 4613

16,01% 14,98% 20,77%

50% of Doors Open

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

2923 2462 3691

13,16% 11,09% 16,62%

One Door of Every Industrial Unit Open

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

1797 1498 2397

8,09% 6,75% 10,79%

All Doors of The Industrial Units Closed

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

461 290 608

2,08% 1,31% 2,74%

Fig. 3. Simulation programme results - comparison of the numbers of people affected by industrial noise (Values calculated by Sound PLAN Software to Rw (the sound insulation value) for each situation investigated in this study)[18].

where

L2 is the sound pressure level in the receiving room (dB); S is the area of the common partition, in square metres; A is is the equivalent absorption area of the receiving room, in square metres

L1 is the sound pressure level in the source room, in decibels; L2 is the sound pressure level in the receiving room, in decibels; S is the area of the free test opening in which the test element is installed, in square metres; A is the equivalent sound absorption area in the receiving room, in square metres.

ISO 10140-2:10 specifies a laboratory method for measuring the airborne sound insulation of building products, such as walls, floors, doors, windows, glazing, etc. The test results can be used to compare the sound insulation properties of building elements, classify elements according to their sound insulation capabilities, help design building products which require certain acoustic properties and estimate the in situ performance in complete buildings. The measurements are performed in laboratory test facilities in which sound transmission via flanking paths is suppressed. The results of measurements made in accordance with this part of ISO 10140 are not applicable directly to the field situation without accounting for other factors affecting sound insulation, such as flanking transmission, boundary conditions and total loss factor. ISO 10140 defines the sound reduction index and the sound reduction index is evaluated using bellow formula. [42]

S R = (L1−L 2 )+10lg ( )(dB) A

The Standardized Level Difference (DnT), the apparent sound reduction index (R’) and the sound reduction index (R) are sound insulation values given for each frequency of the measure spectrum. The ISO 717-1:1996 (revised as ISO 717-1:2013) standard presents a single index for sound insulation related to the ISO 140-4:1998 (revised as ISO 16283-1:2014) and ISO 10140-2:2010 standard, providing a weighted value for insulation indices. These weighted index are called the weighted standardized level difference (DnT,w), the weighted apparent sound reduction index (R’w) and the weighted sound reduction index (Rw). [45,46]. According to the ISO 140-5:1998 (revised as ISO 16283-3:2016) standard, the façade's sound insulation index can be determined by the

(4) 63

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Fig. 4. Simulation programme results - the Lday overview results for all doors of the industrial units open (map 1), 50% of doors open (map 2), one door of every industrial unit open (map 3), and all doors of the industrial units closed (map 4) (Values calculated by Sound PLAN Software to Rw (the sound insulation value) for each situation investigated in this study) [18].

⎛S⎞ Rtr , s=(L1,s−L 2 )+10lg ⎜ ⎟ −3(dB) ⎝A⎠

road traffic method, which uses the noise generated by vehicle traffic passing in front of the building as the sound source. However, because of the inevitable fluctuation of sound levels from the source of emission, they should be measured simultaneously with the sound levels inside the house. For the road traffic method, the ISO 1405:1998 (revised as ISO 16283-3:2016) standard lists the following index to evaluate façade sound insulation: Standardized Level Difference (D2 m, nT) a method for measuring the façade's global sound insulation when the sound source is vehicle traffic and the external microphone is positioned 2 m from the measured surface. [43,44]

Dtr ,2m, nT =(L1,2m −L 2 )+10lg (

T )(dB) T0

(6)

where L1,s is the sound pressure level measured on the test surface outside the building with including reflecting effects from the test specimen and façade (dB); L2 is the sound pressure level in the receiving room (dB); S is the area of the test specimen, in square metres; A is is the equivalent absorption area of the receiving room, in square metres

(5) The subscript tr indicates that the external noise, sound pressure level (L1,s or L1,2 m) is generated by vehicle traffic. The Standardized Level Difference (Dtr,2m,nT) and the apparent sound reduction index (R′tr,s) are sound insulation values given for each frequency of the measure spectrum. The ISO 717-1:1996 (revised as ISO 717-1:2013) standard presents a single index for sound insulation related to the ISO 140–5:1998 (revised as ISO 16283-3:2016) standard, providing a weighted value for the insulation indices. These weighted index are called the weighted standardized level difference (Dtr,2m,nT,w) and the weighted apparent sound reduction index (R′tr,s,w). [45,46].

where L1,2 m is the sound pressure level measured outside the building with the microphone placed 2 m from the measured surface (dB); L2 is the sound pressure level in the receiving room (dB); T is the reverberation time of the receiving room (s); T0 is the reverberation time of reference (T0=0.5 s). Apparent sound reduction index (R’tr,s) measure of the airborne sound insulation of a building element when the sound source is road traffic and the outside microphone position is on the test surface for which the apparent sound reduction index is evaluated using the following formula [43,44]:

2.2.3. Noıse maps calculations The noise map calculations were carried out for four separate situations. The main purpose of this approach was to take account of 64

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Fig. 5. Simulation programme results - the Levening overview results for all doors of the industrial units open (map 1), 50% of doors open (map 2), one door of every industrial unit open (map 3), and all doors of the industrial units closed (map 4) (Values calculated by Sound PLAN Software to Rw (the sound insulation value) for each situation investigated in this study). [18].

(Table 3, Figs. 3–6). The noise level is highest with all doors in the industrial units open. The more doors are closed – expressed in percentage terms – the lower the noise level. Field observations show that during the year at most 50% of doors are open. For this reason, the sound barrier design was based on a 50% open doors situation. The Lday noise map with an open door-rate of 50% yields a sound level of between 65 dBA and 90 dBA in the residential area with 2923 persons affected by noise above the limit value of 65 dBA (Fig. 7). The Levening noise map with an open door-rate of 50% yields a sound level of between 60 dBA and 85 dBA in the residential area with 2462 persons affected by noise above the limit value of 60 dBA (Fig. 8). The Lnight noise map with an open door-rate of 50% yields a sound level of between 55 dBA and 80 dBA in the residential area with 3691 persons affected by noise above the limit value of 55 dBA (Fig. 9).

the changing usage conditions of the industrial units which depends mainly on meteorological data, i.e. the season. During summer, when the temperature rises inside the industrial units, doors and windows are opened reducing the sound insulation value of the building envelope, while in winter all openings are closed in order to preserve the internal heat, thus increasing the Rw value. For this reason it was considered appropriate to distinguish four different states. – All doors of the industrial units closed – One door of every industrial unit open (9,1% opening of the lateral building envelopes) – 50% of doors open (11,2% opening of the lateral building envelopes) – All doors of the industrial units open (22,4% of the lateral building envelopes) The noise maps and areas affected by above-limit noise levels were calculated for these four states. Lden was calculated in accordance with the Turkish Environmental Noise Regulation for 4 m above ground. The maps are grid-type maps with a grid width of 10 m.

3.2. Measurements The measurements have been performed by using B & K 2260 Sound and Frequency Analyser and microphone devices according to ISO 1996-2 and ISO 1996-1 standard conditions. Measurements devices have been calibrated based on the international standards [18,47-49]. At points selected for measurements both industrial and traffic noise are effective (Fig. 10). For this reason daytime industrial noise and daytime noise on a day without industrial activity were measured in order to determine the background noise level (mainly traffic noise).

3. Results and discussion 3.1. Noıse maps The industrial noise maps were established on the basis of the building usage in the study area and for four different types of usage which change the sound insulation of the lateral building envelopes 65

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Fig. 6. Simulation programme results - the Lnight overview results for all doors of the industrial units open (map 1), 50% of doors open (map 2), one door of every industrial unit open (map 3), and all doors of the industrial units closed (map 4) (Values calculated by Sound PLAN Software to Rw (the sound insulation value) for each situation investigated in this study) [18].

Fig. 7. Simulation programme results - Numerical results of the noise map with 50% of doors of the industrial units open; noise level at 4 m height, grid width 10 m – Lday[18].

In Background noise measurements, Measurements were carried out in 16 different measurement point in accordance with TS ISO 1996-2. Measurement were performed during 5 min in the each

measurement point. Receivers were positioned at 1.5 m height from the ground and receivers were directed towards the noise source in the each measurement. The measurement process which is mentioned 66

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Fig. 8. Simulation programme results - Numerical results of the noise map with 50% of doors of the industrial units open; noise level at 4 m height, grid width 10 m – Levening[18].

Fig. 9. Simulation programme results - Numerical results of the noise map with 50% of doors of the industrial units open; noise level at 4 m height, grid width 10 m – Lnight[18].

ground; Δu is the numerical value of the difference between the wind speeds, expressed in metres per second, at 10 m and 0.5 m above the ground; θ is the angle between the wind direction and the direction from source to receiver.

were applied separately for 16 different measurement point (Fig. 10). In practice the measurements were carried out as follows: – With the first measurement industrial and traffic noise were recorded at a time when both were active. – With the second measurement only the traffic noise was recorded at a time with active traffic but not industrial activity. (At weekend, resting time for industrial Units)(Table 4)

Air condition data in measurement time are shown in Table 5. According to air condition data, the minimum ‘R′ value has been found as 1276.3 m (When cos θ maximum value is equal to 1). The distances between receivers and source are given in Table 6. The distance of the 16 measurement points is smaller than the defined minimum ‘R′ value of 1276.3 m ensuring that none of the points is positioned in a sound shadow. The receiver points were added to the simulation programme for the four different states described above. The noise levels at the receiver points were calculated in accordance with the input data of the simulation programme. Field measurements were carried out on

In order to avoid placement of the measuring point in a sound shadow, the standard TS ISO 1996-2 was used for their determination and incorporated in the formula [49]:

R = 3.2/(0.6 Δμ + Δucosθ)

(7)

where Δμ is the numerical value of the difference between the air temperatures, expressed in kelvin, at 10 m and 0.5 m above the 67

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Fig. 10. Industrial estate measurement points [18]. Table 4 Measurement type properties [18]. Measurement Type

Measurement Date

Measurement Hours

Measurement Day

Measurement points

First Measurement (Industrial and Traffic Noise Active) Second Measurement (Only Traffic Noise Active)

20.08.2009

between 09:00–12:00 am (Diurnal) between 14:30–17:30 pm (Diurnal)

Thursday

16 Different Measurement Point 16 Different Measurement Point

05.09.2009

Saturday (At weekend, Resting time for industrial units)

Table 5 Air Condition in Measurement Time (Air condition data obtained from The Official Meteorology Department in Turkey) [18]. Measurement Type

First Measurement (Industrial and Traffic Noise Active) Second Measurement (Only Traffic Noise Active)

The Data Obtained from The Official Meteorology Department in Turkey Wind Speed

Temperature

Δμ (the numerical value of the difference between the air temperatures, expressed in kelvin, at 10 m and 0.5 m above the ground)

Δu (the numerical value of the difference between the wind speeds, expressed in metres per second, at 10 m and 0.5 m above the ground)

4,16 m/s

26C°

0,062 K°

2,47 m/s

4,16 m/s

28C°

0,062 K°

2,47 m/s

Table 6 Industrial Estate Measurement Points - the distance between receiver and source [18]. The Distances Between Receivers and Source Receiver Point Distance From Source (meter)

1 45

2 46

3 42

4 48

5 51

6 160

7 169

8 27

9 36

10 144

11 156

12 125

13 243

14 85

15 198

16 175

It was found that the sound level at some receiver points was lower than predicted under these conditions. The first reason for this mismatch derives from simulation programme model input process. European Commission Working Group Assessment of Exposure to

two days in order to determine the degree of agreement between simulation and actual observation. The usage of the buildings at the time of measurement corresponded to the state of 50% open doors as defined above (Figs. 11 and 12, Table 7).

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Fig. 11. Industrial Estate Measurement Results and Simulation Programme Results - Receiver 2 Measurement Point's Noise Level Values (dBA) [18].

Fig. 12. Industrial Estate Measurement Results and Simulation Programme Results - Receiver 2 Measurement Point's Noise Level Values According to Frequency [18]. Table 7 Industrial Estate Measurement Results and Simulation Programme Results Value (dBA) [18]. Receiver Point

Sound Pressure Level (dBA) Simulation Programme Results

Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver Receiver

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Measurement Results

All Doors of The Industrial Units Closed

One Door of Every Industrial Unit Open

50% of Doors Open

All Doors of The Industrial Units Open

First Measurement Results (Industrial and Traffic Noise Active)

Second Measurement Results (Only Traffic Noise Active)

60,8 57,8 62,1 65,8 63,6 57,8 45,7 61,5 63,6 54,8 50,7 50,2 50,1 59,0 53,7 50,4

74,8 70,2 75,5 78,2 70,9 63,0 51,6 67,4 66,5 57,0 54,2 53,4 53,7 68,3 61,3 56,9

75,7 71,0 78,4 79,6 73,5 66,0 53,3 73,2 76,9 65,2 62,2 67,3 54,5 71,0 62,8 58,0

78,9 74,3 81,3 82,8 76,7 69,4 56,2 76,5 80,2 68,4 64,5 68,5 56,8 73,5 65,5 60,5

65,9 71,2 68,8 69,7 67,8 67,0 60,9 69,9 68,7 68,0 67,7 56,9 57,3 65,7 63,6 60,8

60,7 64,3 66,5 61,5 66,0 63,8 56,8 65,8 60,5 60,8 64,2 52,5 52,0 59,2 55,6 59,1

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Table 8 Using Good Practice Guide for Strategic Noise Mapping input data process which affects simulation programme results [18,36]. Data type

Available Data Type in this study

The method type used in the simulation process (input data)

Accuracy (The tolerance of the simulation programme results)

Building heights

Number of storeys available

1 dB

Occurrence of favourable sound propagation conditions

Average probability of occurrence during the year

Humidity and temperature

nationally defined default values

Multiply number of storeys with the average storey height (e.g. 3 m) Average probability of occurrence during the year Day 50%,Evening 75% and Night 100% favourable propagation conditions Use nationally defined default values

Not exactly defined as numerical value. Defined with symbol. (Accuracy level of defined symbol is low) Not exactly defined as numerical value. Defined with symbol. (Accuracy level of defined symbol is low)

Table 9 The comparison of 50% of Doors Open Simulation Programme Results and First Measurements Results Value (dBA) [18]. Receiver Points Results Value (dBA)

Simulation Programme Results - 50% of Doors Open (X) First Measurement Results (Industrial and Traffic Noise Active) (Y) Differences Between Simulation Programme Results- 50% Of Doors Open and First Measurement Results(X-Y)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

75,7 65,9 9,8

71,0 71,2 −0,2

78,4 68,8 9,6

79,6 69,7 9,9

73,5 67,8 5,7

66,0 67,0 −1

53,3 60,9 −7,6

73,2 69,9 3,3

76,9 68,7 8,2

65,2 68,0 −2,8

62,2 67,7 −5,5

67,3 56,9 10,6

54,5 57,3 −2,8

71,0 65,7 5,3

62,8 63,6 −0,8

58,0 60,8 −2,8

Fig. 13. Simulation programme results - Position and cross section of the sound barrier in the land-use plan under the condition of 50% of the doors of industrial units open [18].

input data process (WG-AEN), the occurrence of favourable sound propagation conditions and humidity-temperature data type accuracy are not defined as numerical value, defined with symbol (This data type effects the results and it is explained with rate (low to high)). Selected building heights data type accuracy level is 1 dB. As a result of this, more than 1 dB can be observed as a tolerable mismatch in noise mapping simulation results due to the noise modelling process. The comparison of 50% of doors open simulation programme results and first measurements results were shown in the Table 9 (The usage of the buildings at the time of measurement corresponded to the state of 50%

Noise (WG-AEN) defines the uncertainties in the noise modelling process and tolerance regarding noise mapping results [36]. According to WG-AEN, slight difference between measurement results and simulation programme results are normal due to the noise modelling process. The model input data defined by WG-AEN is shown in the Table 8. In the table, it is obvious that the model input data affects simulation results. Good Practice Guide for Strategic Noise Mapping (prepared by WG-AEN) is used to determine model input process and data (Table 8). According to Good Practice Guide for Strategic Noise Mapping 70

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Fig. 14. Simulation programme results - overview of current state (without barrier) and absorbing barriers under the 50% open doors condition for Ldaytime, Levening and Lnight[18].

– No investment activities due to the economic recession.

open doors). Also, there are some other reasons for this mismatch. These reasons are listed in below.

Since the economic recession caused a cessation of evening and night activities, only daytime measurements were carried out.

– A drop in production activities due to the economic recession, and the cessation of some activities in some industrial units. – Closure of industrial units due to the economic recession. – Reduction in working hours due to a drop in orders.

3.3. Sound barrier design The noise map established with the condition of 50% open doors 71

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the rate of the open doors is an independent variable from the simulation results and its only depends on the industrial units. On the contrary, the variations of the sound pressure level is affected from the variation of the rate of the open doors. Thus, it can be easily states that derivatives of noise exposure levels with respect to the different opening of the doors of the industrial buildings gives the sensitivity of noise levels to the rate of the opening of the doors. In other words, the variation of noise exposure levels according to the different opening of the doors means how the rate of the open doors to the closed doors affects the noise exposure levels. Thus, the variation of the noise exposure level according to the rate of the open doors can be used in order to examine the sensitivity of noise exposure to the different opening of the doors of the industrial buildings. For instance, in below figure, the variation of the sound pressure level with respect to the rate of open doors in the industrial units has been depicted based on the simulation results of receiver point-1. In the below figure, sound pressure level has been named shortly as “SPL” and also the rate of the open doors has been named shortly as “ROD”. From the point of view numerical analysis, the determination of the derivative of a function is a well-known problem and there are well establish literature about the topic [51,52]. In contrast, empirically derived information that is, data from experiments or field studies are often collected at unequal intervals. Similarly, as in the case of this research study, in the noise mapping studies, measured data are collected from the field studies and there is no a pre-determined mathematical model shows the relation between parameters affects noise exposure level. Such information cannot be analysed with the help of the fundamental numerical analysis methods. In the case of this study, simulation results are discrete data values which vary from one rate of open door to another rate of open door and an approximation to the differentiation of the sound pressure level with respect to the rate of the open doors can be defined. For instance, in the above Fig. 15, the approximation to the derivative of the data point which is represented with ROD2 can be defined as in the below equation.

Fig. 15. The representation of the differentiation of noise exposure levels with respect to the different opening of the doors of the industrial buildings in receiver point-1.

was used for the design of sound barriers necessary in order to assure the limit values of the Environmental Noise Regulation. The barriers were planned with the aid of the simulation programme. The limit values in the Regulation are defined as follows: Lday 65 dBA, Levening 60 dBA, Lnight 55 dBA. These values were entered into the programme and the position of the calculated noise curtain indicated in the map. The red line shows the course of the barrier, the blue line the cross section through the terrain (Fig. 13). In this study, two different barriers were examined with the purpose of achieving acoustic comfort conditions in the region, based on the calculations of the simulation programme. One barrier type is reflective the other sound absorbing. Industrial noise maps were prepared for both barrier types (Fig. 14). 3.4. Sensitivity analysis Mathematically, the derivative, which serves as the fundamental vehicle for differentiation, represents the rate of change of a dependent variable with respect to an independent variable [50]. In case of this study, the measured data represents the relation between the noise exposure levels and the change on the rate open doors of the industrial buildings. If we discuss the simulation results of this research study from the point of data analysis, it is clearly seen that the variations of

∼ d (SPL ) ∆SPL 3 SPL 3 − SPL 2 (ROD2 )= = d (ROD ) ∆ROD3 ROD3 − ROD2

(7)

For a moment, let we assumed that this approximation is very close

Table 10 Sound pressure differences according to sensitivity analysis in receivers (dBA). Receiver Point

Sound Pressure Level (dBA)

Sound Pressure Differences According to Sensitivity Analysis In Receivers (dBA)

Simulation Programme Results

Differentiation of Simulation Programme Results

X1=All Doors of The Industrial Units Closed (0% opening of the lateral building envelopes) 1 60,8 2 57,8 3 62,1 4 65,8 5 63,6 6 57,8 7 45,7 8 61,5 9 63,6 10 54,8 11 50,7 12 50,2 13 50,1 14 59,0 15 53,7 16 50,4 The Average Value of 16 Receiver Point

ΔY1= X2−X1

ΔY2= X3−X2

ΔY3= X4−X3

(11,2% opening of the lateral building envelopes)

X4=All Doors of The Industrial Units Open (22,4% opening of the lateral building envelopes)

75,7 71,0 78,4 79,6 73,5 66,0 53,3 73,2 76,9 65,2 62,2 67,3 54,5 71,0 62,8 58,0

78,9 74,3 81,3 82,8 76,7 69,4 56,2 76,5 80,2 68,4 64,5 68,5 56,8 73,5 65,5 60,5

14,00 12,40 13,40 12,40 7,30 5,20 5,90 5,90 2,90 2,20 3,50 3,20 3,60 9,30 7,60 6,50 9,61

0,90 0,80 2,90 1,40 2,60 3,00 1,70 5,80 10,40 8,20 8,00 13,90 0,80 2,70 1,50 1,10 5,48

3,20 3,30 2,90 3,20 3,20 3,40 2,90 3,30 3,30 3,20 2,30 1,20 2,30 2,50 2,70 2,50 3,78

X2=One Door of Every Industrial Unit Open (9,1% opening of the lateral building envelopes)

X3=50% of Doors Open

74,8 70,2 75,5 78,2 70,9 63,0 51,6 67,4 66,5 57,0 54,2 53,4 53,7 68,3 61,3 56,9

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Fig. 16. The Sensitivity of Noise Exposure to ROD (Ratio of Open Doors) According to Simulation Programme Results – dBA. Table 11 Simulation programme results - comparison of the current state, and the situation with a reflecting and an absorbing sound barrier under the condition of 50% open doors in the industrial estate [18]. Barrier Type – Condition (Industrial Units Working Condition)

Time Period

50% of Doors Open (Without Barrier)

Lday Levening Lnight

50% of Doors Open with Reflective Barrier

50% of Doors Open with Absorptive Barrier

Maximum Value (According to Turkish Environmental Noise Assessment and Management Direction)

SoundPLAN Noise Mapping Simulation Programme Results The total number of people affected by noise when noise levels are higher than the limit value

The ratio of people affected by noise when noise levels are higher than the limit value

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

2923 2462 3691

13,16% 11,09% 16,62%

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

433 162 575

1,95% 0,73% 2,59%

Lday Levening Lnight

Lday < 65 (dBA) Levening < 60 (dBA) Lnight < 55 (dBA)

428 162 554

1,93% 0,73% 2,49%

Fig. 17. Simulation programme results - comparison of the current state, and the situation with a reflecting and an absorbing sound barrier under the condition of 50% open doors in the industrial estate [18].

values of the collected data can be contaminated by some other factors such as unobservable noise sources. In fact, in this study, it is obvious that there is no way to compute the derivative of the variation of the sound pressure level directly and the derivative of the sound pressure level must be estimated from numerical data. However, the estimation

to the right derivative of the sound pressure levels at the point ROD2. Unfortunately, we have to face another obstacle before determination of the relation between the change on the rate of open doors and sound pressure levels. This obstacle is reliability of the data. In reality, for the noise mapping studies, it is also a well-known fact that the numerical

73

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ratio in the facades (related to industrial units working condition) affects noise level. By means of the sensitivity analysis, for an industrial area, it can be clearly states that the sound pressure level is more sensitive to small variations on the number of open doors of industrial buildings when the majority of the doors is closed. In other words, the effect of the change of the ratio of the open doors on the sound pressure levels decreases dramatically with the increasing of the ratio of open doors to the closed doors in an industrial area. This study also indicates that there is a strong relation between field observations and the accuracy of numerical analysis. It is concluded that the industrial noise mapping process should be carried out by means of not only numerical analysis but also field observations. In the city planning process, it is obvious that the location of the industrial areas must be selected properly in terms of common public health. Further, whenever the subject is the common public health, it is a well-known fact that the one of the most distinguished criteria is noise exposure level. Therefore, the determination of some criteria for the noise control of industrial areas in the city planning process can be a further research topic.

of derivatives from numerical data is a classical problem which occurs in many problems of data analysis [43]. In this study, empirically derived information that is, data obtained from the field studies are collected at sixteen different receiver point. Therefore, in this study, in order to estimate more reliable approximation to the derivative of the sound pressure levels, a statistical way has been followed in order to determine the rate of change of sound pressure levels with respect to the different opening of the doors. For this purpose, in the below table, data of the sixteen receiver point has been listed and it is already known that the data of the receivers vary according to different ratios for the opening of the doors of industrial buildings. For each receiver point, according to four different ratio of open doors, the estimation of the derivatives of the sound pressure levels has been calculated. Then, for each ratio of open doors, the mean values of the estimated derivatives has been calculated. The table has been listed in below (Table 10). The mean values of the estimated derivatives of sound pressures with respect to the ratio of open doors has been depicted in below figure (Fig. 16). The result of the calculation clearly indicates that the mean value of the estimated derivatives decreases with the increasing the number of open doors. This means that the sound pressure level is more sensitive to small variations on the number of open doors when the majority of the doors is closed. In other words, the effect of the change of the ratio of the open doors decreases dramatically with the increasing of the ratio of open doors to the closed doors in an industrial area.

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4. Conclusıons The usage condition of the industrial units has a significant effect on the noise exposure level and therefore, the aim of this study is to help researchers for the preparation of the industrial noise maps and to contribute the academic researches. The main purpose of this study was the establishment of a noise map in order to define the prevailing acoustic conditions at the industrial estate, and to define the measures necessary to ensure acoustic comfort conditions in the surrounding residential area. In this research, measurement results verified that the changing usage conditions of the industrial units and their working scenario has a vital importance in industrial mapping process. In this study, four different industrial noise map based on the changing usage conditions of the industrial units were established. In the line of analysis about industrial units working scenario and field observation, sound barrier was designed according to the noise map established with the condition of 50% open doors. A sound barrier design has been proposed in order to reduce the number of people affected by above-limit noise levels. With the proposed design, their number can be reduced considerably (Table 11). Under current conditions in the Ldaytime timeframe 2923 persons are subject to a noise level above 65 dBA; with the construction of a reflecting sound barrier this number is reduced to 433, and with an absorbing barrier to 428. For Lnight (noise limit 55 dBA) the number of currently affected people is 3691. A reflecting barrier would reduce their number to 575, an absorbing barrier to 554 (Fig. 17). For Levening the numbers are 2462 persons without any barrier, and only 162 with either a reflecting or an absorbing sound barrier. If a reflecting barrier is installed, an area of 0.499 km2 would have a noise level above 60 dBA, with an absorbing barrier, the affected area would be 0.496 km2. According to the simulation results, an absorbing sound barrier would yield a slightly better result than a sound reflecting barrier. By means of the main outcomes of this research, a sensitivity analysis, which is related to the different opening of the doors of the industrial building, has been performed scientifically. The results of this sensitivity analysis can be summarized with the following statements. Firstly, this research paper demonstrates that opening door 74

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