- Preliminary experimental verification of current content sliding modelling techniques
- T.Z. Yeow ; G.A. MacRae ; R.P. Dhakal ; B.A. Bradley
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Earthquake engineering
- Keywords: shake table testing ; friction coefficient
- Description
- Most analytical studies focusing on the sliding of building contents usually make an assumption that the friction force-sliding displacement behaviour is elasto-plastic (e.g. friction coefficient remains constant during sliding). This preliminary study uses experimental data to verify if this assumption is reasonable. Shake table tests of a desk on common flooring materials were conducted to investigate the factors influencing friction behaviour, and to observe the behaviour of the contents under sinusoidal motion. Up to a 15% decrease in friction coefficient was observed with either an 80% increase in mass or a 20 times decrease in relative velocity, indicating that the friction coefficient is dependent on these two parameters. A comparison of the experimental and analytical sliding response of the desk under a single sinusoidal loading pattern on carpet flooring was conducted. Results show that the displacement amplitude of a single sliding excursion and the general sliding trend is well approximated using the elasto-plastic assumption. As such, despite the dependence of friction coefficient on sliding mass and velocity, the elasto-plastic behaviour assumption appears to be reasonable for the sinusoidal loading pattern examined in this paper.
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- Preliminary analysis of instrumented Wellington building responses in the July/August 2013 Seddon/Lake Grassmere earthquakes
- E.M. Thomson ; B.A. Bradley
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Earthquake engineering
- Keywords: building response ; Earthquake
- Description
- This paper investigates the dynamic response of five instrumented structures in the greater Wellington region during the July/August 2013 Seddon/Lake Grassmere earthquakes. Six events ranging from Mw 5.6 - 6.6 were considered in the
analysis of five different structures: GNS Science at Avalon, BNZ Centre Port, Majestic Centre, Victoria University Te Puni Village Tower, and Wellington Hospital. This preliminary investigation firstly involved determination of the fundamental period of each structure in the principal horizontal directions, and comparison with the simplified method proposed in NZS1170.5:2004. Secondly, the peak floor level acceleration distributions over the height of the structures were analysed and compared with the
design provisions in NZS1170.5:2004 and ASCE/SEI7:2010., The results illustrate that the simplified equation for fundamental period in NZS1170.5:2004 often underestimated the fundamental period and could result with unconservative design forces when using forced based design, and that both NZS1170.5:2004 and ASCE/SEI7:2010 provisions for floor acceleration contain significant deficiencies due to the omission of the dependence of peak floor acceleration variation with height on vibration period.
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