Acoustical performance of buildings: Current practice ...newbuildscanada.ca/wp-content/uploads/2010/11/Session-2-Vibrations... · NRC‐IRC Indoor Environment Program ‐Acoustics

NRC‐IRC Indoor Environment Program ‐ Acoustics

Acoustical performance of buildings:Current practice, research, and code requirements

NRC - Institute for Research in Construction

Stefan SchoenwaldTrevor Nightingale

NEWBuildS, Research Exchange, June 13th/14th 2011, Ottawa


Outline

• Building Code Requirements in Canada• Current Common Design Practice• Good Acoustical Design Practice• Wood Construction in Canada• Available Research Outcomes and Challenges• Conclusions

2


National Building Code Canada 2010Sound Insulation Requirements

• Code recognizes high levels of sound due to noise intrusion from adjacent spaces in the building as health risk as code objective

• Code addresses only limitation of transmission of airborne sound into a residential unit from spaces elsewhere in the building in its functional statements

• Code provisions require…

o STC 50 (sound transmission class) for airborne sound insulation of building element that separates residential unit from other spaces in the building, or…

o STC 55 in case of elevator hoist way or refuse chute

3


Requirement NBC 2010 Element Performance - STC 50/55

• NBC 2010 assumes that sound is mainly transmitted through partition between dwellings

• Design details of walls and floors for wood buildings in compliance with requirements are given in the building code

STC 50

STC 50

STC 50STC 50

direct

direct

4

Current practice focuses on sound insulation of element only!

Code requirement is not fully consistent with code objective!


Sound Insulation in Real BuildingsSystem Performance

• In buildings occupants perceive apparent airborne sound insulation determined by…

- Direct sound insulation of partition - Flanking sound insulation involving adjoining elements

• NBC Standing Committee on Environmental Separations:Task group deciding on form and technical material necessary to support a likely code change in NBC 2015

• All OECD countries have code requirement for apparent sound insulation except Canada

direct

direct

5

Flanking

Flanking

?

Flanking

Flanking

?

Paradigm shift in building practice!


System Performancevs. Current Practice

Complaints on sound insulation in building:

• Measures at separating element to improve direct sound insulation (e.g. additional layers of gypsum board, resilient channels, etc.)

• However, flanking sound insulation often weakest link

• No improvement of apparent sound insulation experienced by occupantsdirect

6

Flanking

Flanking

? Good building design practice considers system performance!

Flanking

Flanking

?directdirect

direct


Noise sources not addressed by NBC 2010Impact

• Noise generated by people walking on floor assembly and transmitted to adjacent dwellings

• Apparent sound insulation, direct and flanking, must be considered

• No requirement for impact sound insulation in NBC

• All other OECD countries have code requirement for system performance for impact sound insulation

• Number one source of complaint by building occupants

Flanking

direct

Flanking

Flanking

7

?

?Good design practice considers

apparent impact sound insulation!


Noise sources not addressed by NBC 2010Plumbing / Equipment Noise

• Noise generated by plumbing, equipment and HVAC-systems in buildings

• Structure-borne excitation and transmission usually most important

• No NBC requirement to limit plumbing/equipment noise

• Some OECD countries have code requirements to limit noise levels due to building appliances

8

?

? Plumbing/equipment noise should be considered in good building

design practice!


Noise Sources not addressed by NBC 2010Outdoor Noise

• Noise intrusion from outside into the building through exterior walls, curtain walls, facades and roof:

-Traffic noise

-Aircraft noise

• Noise intrusion recognized by World Health Organization (WHO) as health risk (e.g., sleep disturbance)

9

Flanking

Flanking

direct ?

Building envelope must provide appropriate sound insulation!


Occupancy types not addressed by NBCOffices, Commercial,…

Examples:

• Closed Offices and Meeting RoomsSpeech privacy performance and criteria based on sound insulation of complete building system (not just an element)

• Open Plan OfficesWorkers require freedom from distraction, and minimal health/annoyance risks due to noises and interruption

10

Flanking

Flanking

direct

Best practice guides, if available, to be followed for good design practice!


Good acoustical design practiceensures…

• that buildings conform with minimum acoustical code requirements

• occupant satisfaction and market acceptance, by-meeting more stringent acoustical criteria for system

performance -considering other noise sources (impact, exterior noise…)-guaranteeing acoustical conditions necessary for intended

building use (limited background noise, speech security...)

11

Research necessary to provide knowledge base and guidelines!


Wood Construction in Canada

Wood frame / Stick-built• Platform construction• Most common wood construction method in North America• Low-rise buildings (up to and including 4 storey)

Heavy Timber• Post and beam construction, e.g. with Glulam• Cross Laminated Timber (CLT),…• Material of choice for mid-rise buildings in Europe• Emerging market in Canada

Wood-Hybrid• Combination of wood with others (e.g. wood-concrete)• Likely solution for future taller buildings

12


NRC-IRC Research onSound Insulation – Stick-Built

Many research projects with partners (FPInnovations and others) on airborne and impact sound transmission in multi-family wood frame construction• Elements (direct transmission only)- NRC-IRC and industry reports on walls and floors - Code tables

• Systems- Guide for Sound Insulation in Wood Frame Construction, March 2006- “soundPATHS – wood”: “Predictor for Apparent Transmission of Household Sound in

Wood Frame Multi-Family Construction”, planned release 2011

• Design solutions for foreign markets with stringent requirements- “Design Details and Electronic Best Practice Guide for Sound Insulation in Japanese

and Korean 2x4 Multi-Unit Buildings”, COFI Japan/Korea, Japan delivered March 2010

13


Research Challenges forTaller Stick-Built Buildings

Limited or no data for…• Wood frame assemblies with small joist and stud spacing

Decreased spacing of framing members required to carry heavy loads reduces sound insulation (of both the element and building system)

• Shear braced wood frame assemblies with/without tie-downsIncreased shear bracing for seismic and vibration serviceabilityrequirements typically reduces sound insulation (of both the element and building system)

• Fire stops and Fire blockings necessary for mid-rise buildingsFire resistance may require enhanced fire stops and fire blocking at junctions of building elements while maintaining sound insulation (of both the element and building system)

• Hybrid construction (e.g. wood frame with concrete elements)Concrete shear walls and concrete decks may be beneficial in achieving fire and seismic requirements while maintaining sound insulation (of both the element and building system)

• Facades and curtain wallsTypically not used in low-rise construction

14


Research and Challenges – Heavy Timber and CLT

CanadaFPInnovations with FCBA, France: Direct sound insulation of CLT (CLT Handbook)

Sweden, world wide leader in innovative wood systems: Lund University: CLT structuresVäxjö University: Design and evaluation of 8 storey buildings Luleå University of Technology: Modular mid-rise wood buildings

Alpine countries (Austria, Germany, Italy, Switzerland):University of Technology Graz and spin-offs: CLT-elementsRosenheim, IfT, University of Applied Sciences: Solid wood floors with dampersUniversità IUAV di Venezia: CLT-building system

“progettosofie”

COST FP0702 “Net-Acoustics for Timber Based Lightweight Buildings and Elements”, ending November 2011

15

Challenge: Acoustic system performance of Canadian innovative wood construction!


Conclusions forResearch on Sound Insulation

• Many research challenges for sound insulation of innovative wood construction technologies

• Research goal is providing knowledge base for Best Practice and not only compliance with building code

• To achieve the goal…– More stringent requirements than code must be considered– Interdependencies between building disciplines are important– outcomes of other research project must be recognized and

research conducted in parallel must be coordinated

• Knowledge transfer of outcomes necessary to address a wide audience (Guidelines, design tools, etc)

16

Location:Date:

Floor Vibration Serviceability

Lin HuBuilding Systems Scientist

IRC, OttawaJune 13, 2011

Human Activity andFloor Serviceability

@ 2011 FPInnovations. All rights reserved. Copying and redistribution prohibited.

Human Activity and Floor Serviceability

3

Human Activities

Vibrate Air Vibrate Floors

>50 Hz >25 Hz <25 Hz

Occupants hear (impact sound)

Occupants hear(Airborne sound)

Occupants feel (floor movement

or vibration)


Serviceability Issues – View fromFrequency Spectrum

4


Floor Vibration (<25Hz)

5

After S. Ohlsson, 1984, "Springness and human inducedfloor vibration" – A design guide


Controlling Floor Vibrations-Challenges

6

Mysterious Fundamentals

Simple and Reliable Design Method-for Current and Future Floor Constructions

Practical Construction Solutions

On-Line Quality Control Tools for Floor Components


Part-1

7

Mysterious Fundamentals


Issues in Fundamentals

8

Characterize footstep excitation force

Find the common key personality (signature) trait in a broad range of wood-based floors with greatly varied details

Identify the type of floor response to footstep force

Lesson: many floor researchers did not pay attention to the fundamentals, and got lost in the complexities of floor vibrations

Characterize Footstep Force


Current Knowlege of the Characteristics of Footstep Force Generated by Walking

10

30 ms-100 ms duration of the heel impact force of each footstep

continuous series of footsteps consisting of a wave train of harmonics, as a multiple of about 2 Hz, the footstep frequency

the first harmonic at about 2 Hz was the predominant component

Common Key Personality traits of Various Wood-Based Floors


Evolution of Wood-Based Floors

12

1. Lumber joisted floor2. Engineered wood joisted floor

No topping or radiant floor

Topping or radiant floor

Wood topping or radiant floor

Cementitioustopping orradiant floor


Evolution of Wood-based Floors

13

Replace conventionalconcrete-steel trussfloor in non-residentialfloors . . .

3. Hybrid wood floor

Light steel-gauge joistwood deck

Steel trusswood deck

. . . by wood-steel truss hybridfloors



14

(Source: Johann Betz, UBC, 2006)

Under view of a CLT floor

4. Massive wood slab non-joisted floor

Glulam wood slab

Cross-Laminated Timber (CLT)

Innovative massivewood slab

Concept of CLT



15

5. More to come !


How To Find the Common Key Personality Traits

16

Look at the floor constructions, we are lost in the large variety

Go to the fundamentals, we see dynamic properties of wood-based floors are the common key personality trait


Fundamentals – Dynamic Properties

17

Down to earth, only three key parameters control the vibrations of any type of floor:

Mass

Stiffness

Damping


Floor Area Mass Spectrum

18

A continuous spectrum of area mass of various floors (kg/m2)

Type-1 Type-6Type-7

Type-4Type-5

Type-2

Type-3

20 40 50 100 200

Type-1: wood or light steel gauge joisted floor without toppingType-2: wood or light steel gauge joisted floor with wood toppingType-3: steel truss joisted floor with thick wood deckType-4: wood or light steel gauge joisted floor with cementitious topping;

Heavy glulam or timber joist with thick wood deckType-5: massive wood slab non-joisted floor Type-6: steel truss joisted floor with steel-concrete deckType-7: concrete slab non-joisted floor; wood-concrete composite


Floor Fundamental FrequencySpectrum

19

Fundamental natural frequency spectrum of floors

Type-6 and Type-7 floors

SatisfactoryType-2 to Type-5

floors

SatisfactoryType-1 floors

>15 Hz

10 Hz

>10 Hz<10 Hz

Type-1: wood or light steel gauge joisted floor without toppingType-2: wood or light steel gauge joisted floor with wood toppingType-3: steel truss joisted floor with thick wood deckType-4: wood or light steel gauge joisted floor with cementitious topping;

Heavy glulam or timber joist with thick wood deckType-5: massive wood slab non-joisted floor Type-6: steel truss joisted floor with steel-concrete deckType-7: concrete slab non-joisted floor; wood-concrete composite


Damping in Wood-Based Floors

20

Less from material

Major from construction:

- joints- connections- supports- furniture- partitions- human presence- etc.


Damping in Wood-Based Floors

21

Around 3% for base wood-joisted floors

Around 1-2% for base wood-joisted floors with cementitious topping

Around 1% for base wood-massive non-joisted slab floors

Floor Response to Footstep Excitation


Lightweight Floor Responses to Footsteps

23

Vibration response of a field wood-framed floor to footstep force from a person walking

-1.5

-1

-0.5

0

0.5

1

1.5

0 0.5 1 1.5 2 2.5 3

Time (Second)

Acc

eler

atio

n (g

)

Transient response predominates

(Floor fundamental natural frequency > 8-10 Hz, ex. wood-based floors)


Characteristics of Transient Response

24

1) quick diminution

2) taking place at more than one floor natural frequencies

3) peak amplitude is predominately governed by system stiffness and mass


Heavyweight Floor Responses to Footsteps

25

Walking acceleration response of an office floor having a fundamental natural frequency of 5.1 Hz published by Murray, Allen and Ungar

Resonance with a harmonic of the footstep frequency predominates

(Floor fundamental natural frequency < 8-10 Hz , ex. concrete floors)


Characteristics of Resonance

26

1) long lasting 2) taking place at

one natural frequencies

3) peak amplitude is predominantly governed by system damping

0


Human Response to Floor Vibrations

27

1) more tolerant to short duration than long duration vibrations

2) most sensitive to vibrations with frequencies in the range of 4 to 8 Hz


Part-2

28

Development of Simple and Reliable Design Methods

for a Broad Range of Wood-Based Floors


Challenges

29

A simplest method:• Simplest criterion using the parameters can be predicted

and correlated to human perception in a reliable way• Simplest calculation equations capturing the major

construction parameters that significantly affect floor vibration behaviour and human perception

Reliable

For current and future floors


Approaches

30

Field FloorPerformance Testing

Consumer Survey

Floor PerformanceFloor PerformanceIndicators:Indicators:

D, F, A, V, dampingD, F, A, V, damping

Occupants'Occupants'ComfortComfort

Correlation Between Occupant Comfort and Measured Performance

Indicators

FEM Modeling, Simple Equation

Predict Predict PerformancePerformance

IndicatorsIndicators

Laboratory Testing

Verify Verify PredictivePredictive

ToolsTools

Predicted PerformanceIndicators

Vibration Controlled Design Method:

Design Criterion and Predictive Tools


Identify the Significant Construction Parameter through . . .

31

Laboratory study on floors with varying construction parameters to understand their effects on human perception and vibration behaviour

Example – 1

Development of Design Method for Joisted Floors


Step-1: Indentify Performance IndicatorsCorrelated to Human Perception

33

Fundamental Natural Frequency

Root-Mean-Square Acceleration

Peak Acceleration

Initial Velocity

Point Load Deflection + Mass

Point Load Deflection

+


Step-2: Select the Indicators and Predict Them – Design Equations

34

Selected f and d

Chui’s Ribbed Plate Equations: - Include all construction parameter

- Comprehensive

..5,3,1 ..5,3,1

42441

4

14m n

yxyx

kN

DbnD

abmnD

amab

Pd

in m

424

11141

2

bD

abD

aDf yxyx

in H z


Step-3: Correlate Human Perception to Calculated f and d – Design Criterion

35

Where:d1kN = computed 1 kN static deflection of a bare

floorf1 = computed fundamental natural frequency

of a bare floor

7.18)( 44.0

1

1 kNdf

or 27.211 )

7.18( fd kN


Verify the Design Method Using 106 Field Wood-Joisted Floors

36

0

0.5

1

1.5

2

2.5

3

3.5

0 10 20 30 40

Calculated Fundamental Natrual Frequency (Hz)

Cal

cula

ted

1 kN

Sta

tic D

efle

ctio

n (m

m) Design criterion of f/d^0.44>18.7

Acceptable floors by occupants Unacceptable floors by occupants

Example – 2

Development of Design Method for Massive Non-Joisted Wood Slab Floors


Previous Knowledge

38

Human perception correlated to the combination of floor fundamental natural frequency and point load

deflection


Knowledge – CLT Dynamic Behaviour

39

Bare light-weight joisted floor

Bare CLT floor

Bare steel-concrete, concrete slab

floor

Mass/Area (kg/m2) 15-30 30-150 >150

Fundamental Natural Frequency (Hz)

>15 >9 <9

Damping Ratio (%) 3 1 1


Equations to Calculate f and d –Design Equation

40

Simplest

Only use longitudinal stiffness and mass: - Type of current joints not significant- One way behaviour of massive wood slab similar to concrete slab

AEI

lf

meff

1

22142.3

meffEI

Pld 1

3

481000

P = 1000 (N)l = span (m) = density (kg/m3)A = area of 1 m wide CLT (m2 )

= effective apparent stiffness in span direction of 1 m wide CLT (N-m2)

meffEI1


Correlate Human Perception to Calculated f and d – Design Criterion

41

0.137.0 d

f


Verification of the Design Methodfor CLT

42

Predicted CLT floor vibration performance vs. subjective ratings

0.00

0.50

1.00

1.50

2.00

0 2 4 6 8 10 12 14 16 18

Cal

cula

ted

1kN

Sta

tic D

efle

ctio

n(m

m)

Criterion ( f/d 0̂.7>13.0)Unacceptable MarginalAcceptable

Calculated Fundamental Natural Frequency (Hz)

137.0 d

f

>13

<13


Proposed Design Method vs. CLTdesigner

43

CLT thickness (mm)

FPInnovations’design method

proposed span (m)

CLTdesignerproposed span for 1% damping and

no topping floors (m)(Schickhofer, 2010)

100 3.58 3.53120 3.76 3.75140 4.50 4.43160 4.80 4.76180 5.16 5.14200 5.68 5.67220 5.84 5.89240 6.09 6.17


Simple Form of the CLT Design Method

44

l = vibration controlled span (m) = density (kg/m3)A = area of 1 m wide CLT (m2)

meffEI1 = effective apparent stiffness in span direction of 1 m wide

CLT (N-m2)

123.0

293.01

)()(

15.91

AEI

lm

eff


Final Remark

45

Use systems approach to address floor vibration issues

Develop construction solutions to floor vibrations that do not conflict with other performance attributes

© 2011 FPInnovations. All rights reserved. Copying and redistribution prohibited.

® FPInnovations, its marks and logos are registered trademarks of FPInnovations.


To reach us:Lin J. Hu, Ph.D.Scientist – Building Systems418 659-2647 #3103

[email protected]

46

Research Exchange Theme IIOttawa 13-14 June 2011

Session 2 – Vibrations and acoustics

Vibrations of tall buildingsby

Ghyslaine McClureAssociate Professor

McGill University

Outline

• Context of project T2-5-C2 and Goal

• Why measure dynamic characteristics of wood/hybrid buildings?

• Some AVM results for tall buildings in Montreal

• Motivation for future work

2Theme II Research ExchangeOttawa, 13 June 2011

Context of project T2-5-C2Predicting lateral drift and natural period of

mid-rise wood and hybrid buildings

• Phase 1: Measuring the dynamic characteristics of mid-rise wood and hybrid buildings – work with Prof. Ghasan Doudak and Nidaa Elwan (U. of Ottawa)

• Use of AVM on previous PhD research by Damien Gilles (linked to CSRN) to find improved predictors for natural frequencies and damping of tall buildings in Montreal;

http://digitool.library.mcgill.ca/R/

IN SITU DYNAMIC CHARACTERISTICS OF REINFORCED CONCRETE SHEAR WALL BUILDINGS, February 2011.


http://digitool.library.mcgill.ca/R/

Why measure the dynamic characteristics of wood/hybrid buildings?

• Knowledge of these properties essential to predict response to seismic loads; sensitivity to wind gust loads;

• Properties difficult to predict at the design stage and using computer models of building frameworks;

• Accuracy of building code equations is questionable –not developed based on wood/hybrid buildings;

• Important influence/interaction of architectural components; stiffness, mass and damping;

• Are ambient vibrations useful for design under extreme events?


NBCC period formulae


[1] 0.085 h0.75 for steel moment-resisting frames (steel MRF);

[2] 0.075 h0.75 for concrete moment-resisting frames (RC MRF);

[3] 0.1 N for other moment-resisting frames (MRF);

[4] 0.025 h for braced frames (BF);

[5] 0.05 h0.75 for shear walls (SW) and other structures.

Equations [1], [2], and [5] were developed using the fundamental periods of 40 buildings in California (17 steel MRF, 14 RC MRF, and 9 RC SW), which were measured during the 1971 San Fernando earthquake.

Study using AVM on tall buildings

• Between June 2007 and August 2009, ambient vibration tests were performed in 39 buildings in Montréal.

• In 27 of these, reinforced concrete shear walls (RCSW) provided the main resistance to lateral loads.

• Velocities resulting from ambient excitations were recorded at several locations in each building, and the recorded motions were analyzed using Enhanced Frequency Domain Decomposition (EFDD) to obtain the dynamic properties of up to six vibration modes in the low frequency range.

Ottawa, 13 June 2011 Theme II Research Exchange 6

Lennartz LE-3D/5s sensors


Eigenperiod 5 sec

Bandwidth 0.2 - 40 Hz

Temp range -15 to 60 deg C

Sensitivity 400 V/(m/s)

RMS noise at 1 Hz < 1 nm/s

Technical specifications of Lennartz LE-3D/5s sensors

Data set 1 vs. NBCC formula (0.05 h 0.75)


0

1

2

3

4

5

6

0 50 100 150 200 250

Height (m)

Peri

od

(s)

Data set 1

NBCC - Ta

NBCC - Tmax

NBCC - Treg

Extended data base (Data set 2)


0

1

2

3

4

5

6

0 50 100 150 200 250 300

Height (m)

Peri

od

(s)

Gilles

Goel & Chopra

Farsi & Bard

Lee et al

Ghrib & Mamedov

Kijewski-Correa & Pirnia

Data set 2 vs. NBCC formula


0

1

2

3

4

5

6

0 50 100 150 200 250 300

Height (m)

Peri

od

(s)

Data set 2

NBCC - Ta

NBCC - Tmax

NBCC - Treg

Some AVM results for tall buildings in Montreal Fundamental sway period


T a hb1

Table 1: Regression analyses for fundamental sway period

Type b Best-fit se R2

Constrained 0.750 T1 = 0.052 h0.75 0.296 0.738

Unconstrained 1.032 T1 = 0.017 h1.032 0.229 0.898

Constrained 1.000 T1 = 0.019 h 0.230 0.892

Some AVM results for tall buildings in MontrealFundamental sway period


0

1

2

3

4

5

0 50 100 150 200 250

Height (m)

T1 (

s)

Data

NBCC - Treg

Best fit

Best fit (b=1.0)

Recommendation for T1


0

1

2

3

4

5

0 50 100 150 200 250

Height (m)

T1 (

s)

Data

T1 = 0.015 h

T1 = 0.019 h

T1 = 0.025 h

Some AVM results for tall buildings in MontrealSecond sway period


0.0

0.5

1.0

1.5

2.0

0 50 100 150 200 250

Height (m)

T2 (

s)

Trans

Long

T2 = 0.009 h 0̂.9

T2 = 0.007 h 0̂.9

T2 = 0.012 h 0̂.9

Some AVM results for tall buildings in MontrealFundamental torsional period


0

1

2

3

4

5

0 50 100 150 200 250 300

Height (m)

T1

t (s)

Data

T1t = 0.011 h

T1t = 0.015 h

T1t = 0.018 h

Some AVM results for tall buildings in MontrealModal damping


0

1

2

3

4

5

6

0 50 100 150 200 250

Height (m)

Dam

pin

g (

% c

riti

cal)

Trans 1

Long 1

Torsion 1

Trans 2

Long 2

Torsion 2

Some AVM results for tall buildings in Montreal Modal damping in fundamental modes


0

1

2

3

4

5

6

0 1 2 3 4 5

Frequency (Hz)

Dam

pin

g (

% c

riti

cal)

Trans 1

Long 1

Satake et al (x = 1.38f)

Jeary

Lagomarsino

UHS spectral accelerations for Montreal


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 1 2 3 4 5

Period (s)

Sp

ectr

al accele

rati

on

(%

g)

Class A

Class B

Class C

Class D

Class E

References

• D. Gilles, "In situ dynamic properties of buildings in Montréal determined from ambient vibration records", Report No. 2010-03, McGill University Structural Engineering Series, Montréal, QC, 2010. Available at http://www.mcgill.ca/library/library-findinfo/escholarship/.

• NRC/IRC, "National Building Code of Canada 2005", National Research Council of Canada, Institute for Research in Construction, Ottawa, ON, 2005.

• R.K. Goel and A.K. Chopra, "Vibration properties of buildings determined from recorded earthquake motions", Report No. UCB/EERC-97/14, Richmond, CA, 1997.

• S. Lagomarsino. "Forecast models for damping and vibration periods of buildings", Journal of Wind Engineering and Industrial Aerodynamics, 48: 221-239, 1993.

• R.K. Goel and A.K. Chopra. "Period formulas for concrete shear wall buildings", Journal of Structural Engineering, 124(4): 426-433, 1998.

• L.-H. Lee, K.-K. Chang, and Y.-S. Chun. "Experimental formula for the fundamental period of RC buildings with shear-wall dominant systems", The Structural Design of Tall Buildings, 9: 295-307, 2000.


References (cont’d)

• N. Satake, et al. "Damping evaluation using full-scale data of buildings in Japan", Journal of Structural Engineering, 129(4): 470-477, 2003.

• M. Çelebi. "Comparison of damping in buildings under low-amplitude and strong motions", Journal of Wind Engineering and Industrial Aerodynamics, 59: 309-323, 1996.

• A.P. Jeary. "Damping in tall buildings - A mechanism and a predictor", Earthquake Engineering and Structural Dynamics, 14: 733-750, 1986.

• W.P. Fritz, N.P. Jones, and T. Igusa. "Predictive models for the median and variability of building period and damping", Journal of Structural Engineering, 135(5): 576-586, 2009.

• A.K. Chopra and R.K. Goel. "Building period formulas for estimating seismic displacements", Earthquake Spectra, 16(2): 533-536, 2000.

• D. Gilles, "In situ dynamic characteristics of reinforced concrete shear wall buildings", PhD thesis, McGill University, Montréal, QC, 2011. Available at http://www.mcgill.ca/library/library-findinfo/escholarship/.


http://www.mcgill.ca/library/library-findinfo/escholarship/



Motivation for future work for low and medium-rise wood/hybrid constructions

• Natural periods

• Damping

• Challenges for hybrid systems

Thank you for your attention.


Documents

Acoustical performance of buildings: Current practice ...newbuildscanada.ca/wp-content/uploads/2010/11/Session-2-Vibrations... · NRC‐IRC Indoor Environment Program ‐Acoustics