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Puglisi, Giuseppina Emma

Acoustics of theorical urban open spaces through the insertion of vegetation as noise abetment mean : parametric studies and practical guidelines.

Rel. Arianna Astolfi, Jian Kang, Julija Smyrnowa. Politecnico di Torino, Corso di laurea magistrale in Architettura costruzione citta', 2012

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Abstract:

During the last few decades lots of architectures nave moved to a sustainable approach. This means that architects and engineers have started thinking that their projects are products not only for the man but also for the environment, so they began to use strategies to reduce the impact on the Earth and to consider renewable sources like sun, wind, water and earth to respond to human needs. One of the first objects that led to this new point of view in the designing process was the study of the thermal properties of building elements such as walls, façades, roofs and floors. Then it got possible to develop studies on new solutions in order to optimise the behaviour of buildings in accord to the climatic changes; most of all it was possible to advance connections between different fields of study: practices that appeared suitable from a thermal perspective also resulted as convenient from the technological approach for constructive simplicity.

Recent studies have shown that vegetation has potential benefits in increasing the health and well-being of citizens improving the air quality, increasing the insulation of building components, reducing the urban heat-islands effect and limiting the storm water runoff. The objective of this thesis is to investigate the effectiveness of vegetated surfaces applied in urban spaces, analysing green from the acoustical viewpoint. Noise pollution, in fact, is a major environmental problem within the EU and during the last few years vegetation was tested as noise abatement mean; several projects aiming to investigate strategies to reduce traffic noise in urban and rural areas have been initiated considering green as effective element of noise abatement.

One of these projects, in which I have personally been enrolled, is named HOSANNA (Holistic and sustainable abatement of noise by optimized combinations of natural and artificial means), is funded under the 7th FWP (Seventh Framework Programme) and is carried on by researchers from several European Countries including Universities and research centres.

This work of research contributes entirely to the improvement that HOSANNA is proposed to carry out in the dose future, and most of all this study intends to agree with the main objectives of the project like making applicable some prediction methods to abate urban noise (which can also be used in noise mapping softwares), delivering a good practice guide for the end-users, delivering assessment methods for the perceived noise environment, and exploiting that designing green areas and surfaces can minimise the noise impact on citizens and lead to a better use of resources.

This work is an investigation on the effectiveness of three types of green walls in terms of reduction of SPL in two theoretical urban case studies, namely an idealised rectangular square and an idealised octagonal square. Four main aspects of the usage of vegetation in the outdoor spaces were evaluated, so that its influence on the reduction of perception of noise from traffic could be studied: effect of the amount of vegetation, effect of changing in the scattering coefficient of vegetation, effect of vegetation in different receiver positions and effect if vegetation on groups of receivers.

The aim of the investigation was to consider different kinds of theoretical urban open spaces with all their features such as the height of buildings, the width of streets and squares, the length of the streets and type of facade. The entire work of analysis and simulation of the acoustic parameters was carried out with the use of three different software, namely CATT-Acoustic, CRR (Combined Ray-tracing and Radiosity) and Odeon 11, so that the use of vegetation as surface coverage could be evaluated in order to find out some improved layouts that reduce the perception of noise from traffic all over the urban space under exam.

The thesis is divided in four chapters. The first one is the background chapter which contains a series of starting concepts that stand on the base of the practical research. It is about definitions, standardisation and introduction on the uses of vegetation in modem architecture. The second chapter is about theoretical and experimental assumptions, so it describes some laboratory experiments and the studies done to define traffic noise in all its features. A dissertation on the definition of the scattering coefficients used to run simulation and on the theoretical models selected is here provided. Chapter three is about parametric studies: it contains an introduction to the acoustical software used and to the uncertainties referred to the simulation process that must be taken into account, and then the results over the proposed layouts that include vegetation as noise abatement mean to reduce the sound pressure level due to the presence of traffic. The last chapter, number four, is referred to some practical guidelines and on the investigation of technological solutions that enrich the possibility of integrating green coverages with architecture: schematic representations are explored and some examples of existent architectures that use those types of technology are provided. The conclusions and an overview on further works complete the dissertation.

Relatori: Arianna Astolfi, Jian Kang, Julija Smyrnowa
Soggetti: A Architettura > AD Bioarchitettura
S Scienze e Scienze Applicate > SA Acustica
Corso di laurea: Corso di laurea magistrale in Architettura costruzione citta'
URI: http://webthesis.biblio.polito.it/id/eprint/2773
Capitoli:

Introduction

Chapter 1. Background

1.1 Basic assumptions

1.1.1 Soundscape and architecture : state of the art

1.1.2 Propagation of sound in urban public open spaces : indices and relevant terms

1.1.3 A digression on scattering and diffusion phenomena

1.2 Standardisation of the evaluation of soundscape

1.2.1 European guidelines

1.2.2 The Italian horizon

1.3 'Green' in architecture

1.3.1 Introduction: reasons, state of the art

1.3.2 Hints on thermal properties

1.3.3 Hints on CO2 attenuation

1.4 'Green' in acoustics

1.4.1 The need of improving acoustic quality in urban spaces: noise from traffic, noise from people speaking and walking in open spaces

1.4.2 Trees, shrubs and bushes: specific objectives of the project HOSANNA to reduce pollution from traffic noise

1.4.3 Greening architecture : research going on

1.4.4 Previous studies

References

Chapter 2. Theoretical and experimental assumptions

2.1 Laboratory experiments

2.1.1 The reverberation chamber

2.1.2 Evaluation of the absorption and scattering coefficients of vegetation

2.1.3 Experimental results

2.1.4 Previous experiments

2.2 Theoretical models

2.2.1 Spatial configurations

2.2.2 Case study 1 : an idealised rectangular square

2.2.3 Case study 2: an idealised octagonal square

2.3 Conceptual definitions

2.3.1 The presence of traffic: how to consider it

2.3.1.1 Method to define traffic noise

2.3.1.2 Method to define distance between sources: parametric study for the construction of a line source

2.3.2 Definition of scattering coefficients

References

Chapter 3. Parametric Studies

3.1 Acoustic evaluation through simulation software

3.1.1 CATT-Acoustic v8.0

3.1.1.1 Methodology and input data

3.1.1.2 General outputs

3.1.2 Investigations on case studies

3.1.2.1 Case study 1: an idealised rectangular square

3.1.2.1.1 Effect of the amount of vegetation

3.1.2.1.2 Effect of scattering coefficient: parametric studies

3.1.2.1.3 Effect of vegetation on different receiver positions

3.1.2.1.4 Effect of vegetation on groups of receivers

3.1.2.2 Case study 2: an idealised octagonal square

3.12.2.1 Effect of the amount of vegetation

3.1.2.2.2 Effect of vegetation on different receiver positions

3.1.2.2.3 Effect of vegetation on groups of receivers

3.2 Comparison between software: reasons of the investigation

3.2.1 Odeon 11

3.2.1.1 Input data

3.2.1.2 Outputs

3.2.2 CRR (Combined Ray-tracing and Radiosity)

3.2.2.1 Methodology and input data

3.2.2.2 Outputs

3.3 Analysis: comparison between results

3.3.1 Case study 1: an idealised rectangular square

3.3.1.1 Investigation of SPL

3.3.1.2 Investigation of insertion loss

3.3.2 Case study 2: an idealised octagonal square

3.3.2.1 Investigation of SPL

3.3.2.2 Investigation of insertion loss

3.3.3 Conclusions on the comparison between software

References

Chapter 4. Architectural guidelines

4.1 Requirements

4.2 Technological purposes

4.2.1 Vegetated wall

4.2.2 Ivy

4.2.3 Nephrolepis exaltata

References

Conclusions And Future Works

Appendix

Bibliografia:

Chapter 1

- Barry Truax, Handbook for Acoustic Ecology (2nd edition), Cambridge Street Publishing, 2009.

- Renato Spagnolo et al., Manuale di acustica applicata - chapter 4: Rumore nell'ambiente

esterno, p. 259, ed. CittàStudi, Torino, 2008.

- Mags Adams et al., Soundscapes: an urban planning process map, InterNoise, Ottawa

(Canada), August 23-26, 2009.

- T.J. Cox, P. D'Antonio, Acoustic absorbers and diffusers. Theory, design and application (2nd

edition), Taylor & Francis Group, Abingdon (Oxon), 2009.

- M. Vorlander, Auralization. Fundamentals of acoustics, modelling, simulation, algorithms and

acoustic virtual reality (1st edition), Springer, Berlin, 2008.

- F. Alton Everest, Master handbook of acoustics (4th edition), McGraw-Hill, New York, 2001.

- T. J. Cox, B.-I.L. Dalenback, P. D'Antonio, J.J. Embrechts, J.Y. Jeon, E. Mommertz, M. Vorlander, A tutorial on scattering and diffusion coefficients for room acoustic surfaces, Acta Acustica united with Acustica, voi. 92, 2009,1-15

- H. Onaga, J.H. Rindel, Acoustic characteristics of urban streets in relation to scattering

caused by building façades, Applied Acustics, vol. 68, 2007, 310-325

- BS 8233 :1999, Sound insulation and noise reduction for buildings - Code of practice

- www.cost.eu (last consultancy September 13th, 2012)

- D.P.C.M. 14 novembre 1997, Gazzetta Ufficiale - Serie generale n. 280 del 1 gennaio 1997.

- http://ngm.nationalgeographic.com/2009/05/green-roofs/klinkenborg-text (last consultancy

September 13th 2012)

- E. Alexandri and P. Jones, Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates, Building and Environment n. 43, 2008.

- F. Ariaudo, S.P. Corgnati, G.V. Fracastoro, D. Raimondo, Cooling load reduction by green walls: results from an experimental campaign, 4th International Building Physics Conference, Istanbul, 15-18 June 2009.

- L. Bianco, V. Serra, F. Larcher, M. Perino, Experimental assessment of a green wall modular System: effects on heat transfer and on surface temperature control.

- T. Takakura, S. Kitade, E. Goto, Cooling effect of greenery cover over a building, Energy and Buildings n. 31, 2000, 1 -6.

- H. Akbari, Shade trees reduce building energy use and C02 emissions from power plants,

Environmental Pollution n. 116, 2002, 119-126.

- Jian Kang, Urban sound environment, Taylor & Francis Group, Abingdon (Oxon), 2007.

- Edited by G. Arie, Quaderni del manuale di progettazione edilizia - le tecnologie e le tecniche, Hoepli, Torino, 2006.

- F. La Malva, A. Astolfi, P. Bottalico, F. Pellerey, Environmental qualìty investigation in a

historical urban space.

- Yuliya Smyrnova, Jian Kang, Chris Cheal, Hong-Seok Yang, Numerical simulation of the effects of vegetation on sound fields in urban spaces, Forum Acusticum 2011, Aalborg (Denmark).

- BS ISO 17497-1 : 2004, Acoustics - Sound scattering properties of surfaces. Part 1: Measurement of the random-incidence scattering coefficient in a reverberation room.

- C.Y. Cheng, K.K.S. Cheung and L.M. Chu, Thermal performance of a vegetated cladding System on façade walls, Building and Environment n. 45, 2010, 1779-1787.

- T. Sternberg, H. Viles, A. Cathersides, Evaluating the role of ivy (Hedera helix) in moderating wall surface microclimates and contributing to the bioprotection of historic buildings, Building and Environment n. 46, 2011, 293-297.

- G. Papadakis, P. Tsamis, S. Krystis, Cooling an experimental investigation of the effect of

shading with plants for solar control of buildings, Energy and Buildings n. 33, 2001, 831-836.

- N.H. Wong, A.Y.K. Tan, Y. Chen, K. Sekar, P.Y. Tan, D. Chan, K. Chiang, N.C. Wong, Thermal evaluation of vertical greenery System for building walls, Building and Environment n. 45, 2010, 663-672.

- M. Köhler, Session 5.2: Living walls and vertical gardens. Living wall systems - a view back and some visions, Greening rooftops for sustainable communities, Boston, 11-12 May 2006.

- M. Schmidt, Session 5.3: Aesthetics and cooling - green roofs and walls. The evapotranspiration of greened roofs and façades, Greening rooftops for sustainable communities,

Boston, 11-12 May 2006.

- Finn Jacobsen, The sound field in a reverberation room, Report for the Technical University of Denmark.

- W.P. Jones, Air conditioning applications and design (2nd edition), Arnold edition, London, 1997.

Chapter 2

- BS EN ISO 354: 2003, Acoustics - Measurement of sound absorption in a reverberation room.

- BS ISO 17497-1 : 2004, Acoustics - Sound scattering properties of surfaces. Part 1: Measurement of the random-incidence scattering coefficient in a reverberation room.

- H.S. Yang, C. Cheal, J. Kang, Random-incidence absorption and scattering coefficients of low- growing vegetation, EuroNoise, Prague, 2012.

- N.H. Wong, A.Y.K. Tan, P.Y. Tan, K. Chiang, N.C. Wong, Acoustics evaluation of vertical greenery systems for building walls, Building and Environment 45 (2010), 411-420.

- Renez Nota, Robert Barelds, Dirk van Maercke, Technical report: Harmonoise WP 3 engineering method for road traffic and railway noise after validation and fìne-tunìng (Document Identity: HAR32TR-040922-DGMR20), 20 January 2005.

- BS 8233 :1999, Sound insulation and noise reduction for buildings - Code of practice.

- Calculation of road traffic noise, Department of transport - Welsh office.

- Jérome Defrance, Jens Forssén, Timothy Van Renterghem, Keith Attenborough, Maarten Hornix, Work Package 2: innovative barries exploiting natural materials. Technical report on proposal for common cases of study. (Document Identity: HSNNA_23_TRP_2011_02_21_CSTB03.doc), 4 April 2011.

- Maarten Hornix, Julija Smyrnowa, Timothy Van Renterghem, Chris Cheal, Jian Kang, Work Package 5: green buildings. Technical report on acoustic simulation tools for urban streets, squares and road-side courtyards integrating vegetation. (Document Identity: HSNNA_53_TRP_2011_10_28_CTH10.docx), 28 October 2011.

- Odeon v.11 user manual

Chapter 3

- UNI TR11326-parte 1, Valutazione dell'incertezza nelle misurazioni e nei calcoli di acustica.

- CATT-Acoustic v.8 user manual

- Maarten Hornix, Julija Smyrnowa, Timothy Van Renterghem, Chris Cheal, Jian KANG, , Work Package 5: green buildings. Technical report on acoustic simulation tools for urban streets, squares and road-side courtyards integrating vegetation. (Document Identity:

HSNNA_53_TRP_2011_10_28_CTH10.docx), 28 October 2011.

- B. Truax, Handbook for Acoustic Ecology (2nd edition), Cambridge Street Publishing, 2009.

- Odeon v.11 user manual

- Yan Meng, Acoustic simulation and auralisation in urban open spaces, Doctor of Philosophy

Thesis, School of Architecture - University of Sheffield, July 2008

Chapter 4

- Patrick Blanc, The Vertical Garden: a scientific and artistic approach by Patrick Blanc. Available on http://www.verticalgardenpatrickblanc.com/#/en/resources.

- www.plantsonwalls.com (last consultancy September 13th 2012)

- Philip Jodidio, Green: architecture now!, Taschen, Cologne, 2009.

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