• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
PBWE - IN VENTO 2014 - Petrini StroNGER.com
 

PBWE - IN VENTO 2014 - Petrini StroNGER.com

on

  • 121 views

Building occupants’ comfort assessment in the PBWE framework. ...

Building occupants’ comfort assessment in the PBWE framework.
by
Francesco Petrini, Pierluigi Olmati and Franco Bontempi.

This research deals with the problem of the comfort assessment of high-rise building occupants under wind action. Also if the problem has been studied by there searchers and by the civil engineering industry during last thirty years, appropriate methods to handling the design of high-rise buildings in order to avoid wind-induced
occupant discomfort has not been defined yet, mainly due to the high uncertainties involved in the determination of both the demand and the sensitivity of the building occupants to wind-induced vibrations. The main issues related with this problem are first summarized, then the growing, pioneering performance-based wind engineering (PBWE) approach is proposed as tool to handle the problem. The required analyses are presented and discussed on both the conceptual and operational point of view. A case-study is then presented in order to demonstrate the effectiveness of the proposed approach. In the PBWE view, the contribution of the work is focused on the procedural step identified as “damage analysis”, something that, in authors’ knowledge,has not been yet developed in the literature.

Statistics

Views

Total Views
121
Views on SlideShare
117
Embed Views
4

Actions

Likes
1
Downloads
0
Comments
0

2 Embeds 4

https://www.linkedin.com 3
https://twitter.com 1

Accessibility

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    PBWE - IN VENTO 2014 - Petrini StroNGER.com PBWE - IN VENTO 2014 - Petrini StroNGER.com Presentation Transcript

    • Building occupant comfort assessment in the PBWE framework Francesco Petrini*, Pierluigi Olmati, Franco Bontempi francesco.petrini@uniroma1.it , francesco.petrini@stronger2012.com -- *Research Associate, School of Civil and Industrial Engineering, Sapienza Università di Roma Via Eudossiana 18 - 00184 Rome (ITALY) tel. +39-06-44585072 StroNGER S.r.l., Co-founder and Director Via Giacomo Peroni 442-444, Tecnopolo Tiburtino, 00131 Rome (ITALY) -- Genova 25 June 2014
    • - Building occupant comfort - PBWE: state of development - Objective of this study Intro Francesco Petrini. francesco.petrini@uniroma1.it
    • Building occupant comfort – issues In-Vento2014.June22-252014 Approach to the problem (comfort thresholds) Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it 3
    • Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 4 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Field experiment and surveys Motion simulator and shake table Field experiment with artificial excitation K. C. S. Kwok, P. A. Hitchcock, M. D. Burton.(2009). “Perception of vibration and occupant comfort in wind- excited tall buildings”, Journal of Wind Engineering and Industrial Aerodynamics, 97 (2006), 368-380. Building occupant comfort – issues Approach to the problem (comfort thresholds) Some discordance between the results obtained by different authors
    • Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 5 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Human behavior/ psychology Occupants Owners Rest of the population (building reputation) Wind field Structural system (e.g. damping) Aerodynamics (e.g. vortex shedding) Age, occupation, position,…. INTERACTIONS C. Pozzuoli, G. Bartoli, U. Peil, M. Clobes (2013). "Serviceability wind risk assessment of tall buildings including aeroelastic effects" J. Wind Eng. Ind. Aerodyn. 123 (2013), 325–338. Building occupant comfort – issues Approach to the problem (comfort thresholds)
    • Approach to the problem (comfort thresholds) Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 6 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Wind direction Oscillation Wind storm duration Waveform Frequency Amplitude Significant parameters for describing the structural response Peak accel. RMS of accel. T. Kijewski-Correa, D. Pirnia (2009). “Pseudo-Full-Scale” Evaluation of Occupant Comfort in Tall Buildings. 11th Americas Conference on Wind Engineering, San Juan, PR, USA June 22-26, 2009 Building occupant comfort – issues
    • Approach to the problem (comfort thresholds) Building occupant comfort – issues Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 7 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Shape Control Damping Optimization http://www.squidoo.com/taipei101 … Spence, S.M.J., Gioffrè, M. (2012), “Large Scale Reliability-Based Design Optimization of Wind Excited Tall Buildings”, Probabilistic Engineering Mechanics, 28: 206-215. K. T. Tse, K. C. S. Kwok and Y. Tamura (2012). “Performance and Cost Evaluation of a Smart Tuned Mass Damper for Suppressing Wind-Induced Lateral-Torsional Motion of Tall Structures”. Journal of Structural Engineering, 138(4) http://misfitsarchitecture.com/tag/atkins/ http://www.ctbuh.org
    • Approach to the problem (comfort thresholds) Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 8 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Structure Wind-structure interactions Environment (free-field wind) Perception thresholds, task disruptions thresholds ….. Ciampoli M., Petrini F., Augusti G., (2011). “Performance-Based Wind Engineering: towards a general procedure”, Structural Safety, 33 (6), 367-378 Building occupant comfort – issues
    • Approach to the problem (comfort thresholds) Francesco Petrini. Co-founder and Director francesco.petrini@stronger2012.com In-Vento2014.June22-252014 9 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Petrini F., Gkoumas K., Bontempi F. (2013). “Damage and loss evaluation in the performance-based wind engineering”, ICOSSAR 2013 Conference, June 16-20 2013, Columbia University, New York, USA Loss analysis Damage analysis - Direct VS indirect cost that are not possible to account for in monetary terms. - Initial VS life-cycle cost. In particular regarding the evaluation of retrofitting strategies that could improve the serviceability performance (e.g. comfort), by means of vibration mitigation. Building occupant comfort – issues
    • Approach to the problem (comfort thresholds) In-Vento2014.June22-252014 10 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Building occupant comfort – issues Do we have a rational and coherent tool to potentially manage all these issues? Francesco Petrini. Co-founder and Director francesco.petrini@suniroma1.it
    • Approach to the problem (comfort thresholds) Francesco Petrini. Co-founder and Director francesco.petrini@suniroma1.it In-Vento2014.June22-252014 11 Prominent factors Main analysis parameters Uncertain aspects Monetary supremacy Design solutions Building occupant comfort – issues Do we have a rational and coherent tool to potentially manage all these issues? YES, we have the Performance Wind Engineering (PBWE) approach
    • A PBWE Framework from Rome O f(IM|O) f(IM) f(IP|IM,SP) f(IP) f(EDP|IM,IP,SP) G(EDP) f(DM|EDP) G(DM) f(DV|DM) G(DV) Hazard analysis Interaction analysis Structural analysis Damageanalysis Loss analysis IM: intensity measure IP: interaction parameters EDP:engineering demand param. DM:damage measure DV: decision variable Select O, D O:location D: design Environme nt info Decision- making D f(SP|D) f(SP) Structural characterization SP:structural system parameters Structural system info G(DV) = ∫…∫ G(DV|DM) · f(DM|EDP) · f(EDP|IM, IP, SP) · f(IP|IM,SP) · · f(IM) · f(SP) · dDM · dEDP · dIP · dIM · dSP Interaction Parameters Structural Parameters Intensity measure IM IPSP Engineering Demand Parameters EDP Damage Measure DM Decision Variable DV G(·|·) is a conditional complementary cumulative distribution function f(·|·) is a conditional probability density function= progress with respect to the Performance-Based Seismic Design * * * Extension of the Performance-Based Seismic Design procedure proposed by PEER Research center In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it 12 Ciampoli M., Petrini F., Augusti G., (2011). “Performance-Based Wind Engineering: towards a general procedure”, Structural Safety, 33 (6), 367-378 In-Vento2014.June22-252014
    • This paper 1
    • 14 O f(IM|O) f(IM) f(IP|IM,SP) f(IP) f(EDP|IM,IP,SP) G(EDP) f(DM|EDP) G(DM) f(DV|DM) G(DV) Hazard analysis Interaction analysis Structural analysis Damageanalysis Loss analysis IM: intensity measure IP: interaction parameters EDP:engineering demand param. DM:damage measure DV:decision variable Select O, D O: location D:design Environme nt info Decision- making D f(SP|D) f(SP) Structural characterization SP:structural system parameters Structural system info Damage analysis Probabilistic damage analysis: assign a probability distribution to the task disruptions thresholds Procedure: obtain a pdf that assigns at each vibration level a percentage of persons that experience discomfort Vibration and occupant comfort issues Not developed in literature for non-hurricane winds (Caracoglia and Seo did something on Bridges with respect to flutter; Tse, Kwok and Tamura evaluated the costs of a TMD for suppressing discomfort) In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 Kwok, K.C.S., Hitchcock, P.A., 2008. Occupant comfort test using a tall building motion simulator. In: Proceedings of Fourth International Conference on Advances in Wind and Structures, Jeju, Korea, 28–30 May. Ciampoli et al. 2011Petrini et al. 2012 Spence et al. 2013 14
    • Starting point. Past studies (I): Case study Loss of serviceability Lossofintegrityof non-structural elements Motionperception bybuilding occupants Displacements Accelerations Reduced formulation Structure • 74 floors • Height H=305m • Footprint B1=B2=50m FE Model Approximately • 10,000 elements • 4,000 nodes • 24,000 DOFs centralcore 3dframeontheexternalperimeter Bracingsystem w(t;z2)Vm(z2) Vm (z1) Vm (z3) V(t;z2) v(t;z2)u(t;z2) X Z Y θ B1 B2 H 15 In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 G(EDP) = ∫…∫ G(EDP|IM, IP, SP) · f(IP|IM,SP) · f(IM) · f(SP) · dIP · dIM · dSP 15
    • 1 10 100 0,1 1 a[cm/s2] f [Hz] Office Apartment Starting point. Past studies (II): occupant comfort Loss of serviceability Lossofintegrityof non-structural elements Motionperception bybuilding occupants Displacements Accelerations DETERMINISTIC Perception thresholds for occupant comfort Annual occurrenceStochastic variables w(t;z2)Vm(z2) Vm (z1) Vm (z3) V(t;z2) v(t;z2)u(t;z2) X Z Y θ B1 B2 H 16 In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 Ciampoli M, Petrini F. (2011). “Performance-Based Aeolian Risk assessment and reduction for tall buildings”, Probabilistic Engineering Mechanics, 28, 75–84. EDP = aL p TMD 16
    • 1 10 100 0,1 1 a[cm/s2] f [Hz] Office Apartment Starting point. Past studies (II): occupant comfort Loss of serviceability Lossofintegrityof non-structural elements Motionperception bybuilding occupants Displacements Accelerations DETERMINISTIC Perception thresholds for occupant comfort Annual occurrenceStochastic variables w(t;z2)Vm(z2) Vm (z1) Vm (z3) V(t;z2) v(t;z2)u(t;z2) X Z Y θ B1 B2 H 17 In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 Ciampoli M, Petrini F. (2011). “Performance-Based Aeolian Risk assessment and reduction for tall buildings”, Probabilistic Engineering Mechanics, 28, 75–84. EDP = aL p TMD 17
    • Damage analysis Francesco Petrini. francesco.petrini@uniroma1.it O f(IM|O) f(IM) f(IP|IM,SP) f(IP) f(EDP|IM,IP,SP) G(EDP) f(DM|EDP) G(DM) f(DV|DM) G(DV) Hazard analysis Interaction analysis Structural analysis Damageanalysis Loss analysis IM: intensity measure IP: interaction parameters EDP:engineering demand param. DM:damage measure DV:decision variable Select O, D O: location D:design Environme nt info Decision- making D f(SP|D) f(SP) Structural characterization SP:structural system parameters Structural system info
    • Fragility: the fragility in terms of damage measure G(DM|EDP) in this case can be specialized as G(NP≥np|a) Where Np =random variable describing the number of people perceiving the motion np = specific value assumed by Np , thus representing the limit state f(a)= PDF of the engineering demand parameter (EDP) G= Cumulative Distribution Function DM=Np In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 Definition of the damage index Damage definition: someone building occupant perceives the motion (NOTE THAT this will not necessarily cause a task disruptions); Damage Measure (DM): number of building occupants perceiving the motion (under the assumption that this number is directly proportional to the number of occupants suffering for a task disruptions); 19
    • G( Np> np | a ) = 1 G( Np > np | a ) = 0 a b c a[mm/s2] f [Hz] Np= np fn ∆a sample i a [mm/s2] a c b G(Np>np|a) fn ∆a ∆a: acceleration range where the fragility varies due to the uncertanties The results from literature (all author) on the motion perception provide several curves, each one (specific author) representing the acceleration threshold for which a certain number of people (np e.g. 5%) perceives the motion as a function of the fundamental natural frequency of the building. Focusing on a specific number of people perceiving motion, different authors provided different curves, and these curves do not match because the uncertainty and variability of the motion perception of the building occupants (variability of the group of people - aleatory uncertainty) and because of the different approach used by the authors in assessing it (error in measures or different measure technique - epistemic uncertainty). How we can quantify the fragility? – literature data and STRONG assumptions In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 20 (Single author) ASSUMPTIONS • Considering a specific frequency (e.g. the first structural natural frequency of the building), the value of the acceleration threshold for which np people perceive the motion is hypothesized to be log-normally distributed. • Task disruptions coincides with motion perception • Subjects do not show differences of sensitively between sinusoidal and random motions (aggregation of different experiments from literature – neglecting part of the epistemic uncertainty) • The effects of body posture, motion direction, age, sex (Kanda et al., 1988) are not deeply significant in comparison with the individual differences in the motion perceptions thresholds (invariability of the statistics on perception with the differences in group of people – neglecting part of the aleatory uncertainty). Interpretationofthedata fromtheliterature
    • 0 20 40 60 80 100 120 140 160 0 25 50 75 100 Chen and Robertson, 1972 Tamura et al., 1988 Kanda et al., 1994 Tamura et al., 2006 (1) Tamura et al., 2006 (2) Tamura et al., 2006 (3) Tamura et al., 2006 (4) Tamura et al., 2006 (5) a[mm/s2] Np [%] fn=0.187 Hz -0.25 0 0.25 0.5 0 25 50 75 100 Np [%] fn=0.187 Hz ([-] Acceleration thresholds in function of Np for the structural natural frequency of 0.1873 Hz. In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 21 Literature crude results Dispersion of the results Result for the case-study building – literature data
    • 0 0.25 0.5 0.75 1 0 20 40 60 80 G(Np≥np|a) a [mm/s2] original design modified design In-Vento2014.June22-252014In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it 22 Result for the case-study building – fragility
    • • We have some design measures (e.g. insertion of passive control devices) for reducing the vibration perception of building occupants. But the effectiveness of the measure must be evaluated in terms of cost (by computing the probability of exceeding acceptable values of an appropriate DV). • PBWE is a powerful tool for this purpose • Damage and loss analysis of wind-induced vibrations need to be based on corroborated literature studies. • A lot of research work is necessary in order to characterize the uncertainties affecting the problem. 23 Conclusions and further research In-Vento2014.June22-252014 Francesco Petrini. Co-founder and Director francesco.petrini@uniroma1.it In-Vento2014.June22-252014 23 RINGRAZIAMENTO Un caro ringraziamento a MARCELLO CIAMPOLI (deceduto il 13 Dic. 2013), che mi ha insegnato veramente tanto sulla ricerca (principalmente sul PBD) ma che, soprattutto, mi ha insegnato che non bisogna mai prendersi troppo sul serio. Francesco Petrini (25/06/2013)