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Modelling of crowd-induced vibrations in stadium terraces
Human-induced vibrations are increasingly becoming an issue of great concern in the design of civil engineering structures. In this research work, three major trends that contribute to the prevalence of human-induced vibrations in public structures were identified. While the focus has been mainly on...
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| Format: | Thesis |
| Language: | English |
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Department of Civil Engineering
2014
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| _version_ | 1867613157719015424 |
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| access_status_str | Open Access |
| author | Nhleko, Sifiso P |
| author2 | Zingoni, Alphose |
| author_browse | Nhleko, Sifiso P Zingoni, Alphose |
| author_facet | Zingoni, Alphose Nhleko, Sifiso P |
| author_sort | Nhleko, Sifiso P |
| collection | Thesis |
| description | Human-induced vibrations are increasingly becoming an issue of great concern in the design of civil engineering structures. In this research work, three major trends that contribute to the prevalence of human-induced vibrations in public structures were identified. While the focus has been mainly on sports stadia, the known effects of humans on the vibration behaviour of structures in general were also reviewed. Existing design and theoretical models for predicting the effects of humans on structures were examined with two issues being raised. Firstly, the existing force model for describing load impulses resulting from jumping has been found to be unable to predict the correct shape of the impulse or its dominant harmonic for jumping frequencies that are significantly less than 2 Hz. Secondly, there is experimental evidence to show that active humans not only excite a structure through footfall-induced forces, but that they also affect the dynamic properties of the structural system, namely its natural frequencies and damping. However, the existing modelling approach assumes that humans engaged in continuous movement can act only as an input force in the dynamics of the vibrating system. To address both these issues, a new modelling approach, termed 'the pseudo-variable mass model' has been proposed in this study. This method is based on the treatment of the structure-jumper system as a pseudo-variable mass system. The predictions of both the existing and the proposed models were compared with the actual results of experimental investigations involving 10 jumpers, jumping on a lightweight-flexible structure at frequencies of 1 Hz and 1.5 Hz. Comparisons with other findings in the literature were also made. This study showed that the proposed model can adequately predict four observed phenomena, namely, the impulse shape, the dominant harmonic of the impulse, the dominant harmonic in the acceleration response and the effect on the fundamental frequency. Thus, for safe and economic design of lightweight and flexible structures, the proposed model may be used to simulate the effects of jumping at frequencies that are significantly less than 2 Hz. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/6684 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:31:41.113Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Civil Engineering |
| publisherStr | Department of Civil Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/6684 Modelling of crowd-induced vibrations in stadium terraces Nhleko, Sifiso P Zingoni, Alphose Civil Engineering Human-induced vibrations are increasingly becoming an issue of great concern in the design of civil engineering structures. In this research work, three major trends that contribute to the prevalence of human-induced vibrations in public structures were identified. While the focus has been mainly on sports stadia, the known effects of humans on the vibration behaviour of structures in general were also reviewed. Existing design and theoretical models for predicting the effects of humans on structures were examined with two issues being raised. Firstly, the existing force model for describing load impulses resulting from jumping has been found to be unable to predict the correct shape of the impulse or its dominant harmonic for jumping frequencies that are significantly less than 2 Hz. Secondly, there is experimental evidence to show that active humans not only excite a structure through footfall-induced forces, but that they also affect the dynamic properties of the structural system, namely its natural frequencies and damping. However, the existing modelling approach assumes that humans engaged in continuous movement can act only as an input force in the dynamics of the vibrating system. To address both these issues, a new modelling approach, termed 'the pseudo-variable mass model' has been proposed in this study. This method is based on the treatment of the structure-jumper system as a pseudo-variable mass system. The predictions of both the existing and the proposed models were compared with the actual results of experimental investigations involving 10 jumpers, jumping on a lightweight-flexible structure at frequencies of 1 Hz and 1.5 Hz. Comparisons with other findings in the literature were also made. This study showed that the proposed model can adequately predict four observed phenomena, namely, the impulse shape, the dominant harmonic of the impulse, the dominant harmonic in the acceleration response and the effect on the fundamental frequency. Thus, for safe and economic design of lightweight and flexible structures, the proposed model may be used to simulate the effects of jumping at frequencies that are significantly less than 2 Hz. 2014-08-28T09:09:53Z 2014-08-28T09:09:53Z 2005 Thesis http://hdl.handle.net/11427/6684 eng application/pdf Department of Civil Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Civil Engineering Nhleko, Sifiso P Modelling of crowd-induced vibrations in stadium terraces |
| title | Modelling of crowd-induced vibrations in stadium terraces |
| title_full | Modelling of crowd-induced vibrations in stadium terraces |
| title_fullStr | Modelling of crowd-induced vibrations in stadium terraces |
| title_full_unstemmed | Modelling of crowd-induced vibrations in stadium terraces |
| title_short | Modelling of crowd-induced vibrations in stadium terraces |
| title_sort | modelling of crowd induced vibrations in stadium terraces |
| topic | Civil Engineering |
| url | http://hdl.handle.net/11427/6684 |
| work_keys_str_mv | AT nhlekosifisop modellingofcrowdinducedvibrationsinstadiumterraces |