Pub Date : 2018-06-30DOI: 10.5459/BNZSEE.51.2.105-112
N. K. Hazaveh, G. Rodgers, J. Chase, S. Pampanin
Viscous fluid damping has been used worldwide to provide energy dissipation to structures during earthquakes. Semi-active dissipation devices have also shown significant potential to re-shape structural hysteresis behaviour and thus provide significant response and damage reduction. However, semi-active devices are far more complex and costly than passive devices, and thus potentially less robust over time. Ideally, a passive device design would provide the unique response behaviour of a semi-active device, but in a far more robust and low-cost device. This study presents the design, development and characterization of a passive Direction and Displacement Dependent viscous damping (D3) device. It can provide viscous damping in any single quadrant of the force-displacement hysteresis loop and any two in combination. Previously, this behaviour could only be obtained with a semi-active device. The D3 device is developed from a typical viscous damper, which is tested to evaluate the baseline of orifice sizing, force levels and velocity dependence. This prototype viscous damper is then modified in clear steps to produce a device with the desired single quadrant hysteresis loop. The overall results provide the design approach, device characterization and validation for this novel device design.
{"title":"Passive direction displacement dependent damping (D3) device","authors":"N. K. Hazaveh, G. Rodgers, J. Chase, S. Pampanin","doi":"10.5459/BNZSEE.51.2.105-112","DOIUrl":"https://doi.org/10.5459/BNZSEE.51.2.105-112","url":null,"abstract":"Viscous fluid damping has been used worldwide to provide energy dissipation to structures during earthquakes. Semi-active dissipation devices have also shown significant potential to re-shape structural hysteresis behaviour and thus provide significant response and damage reduction. However, semi-active devices are far more complex and costly than passive devices, and thus potentially less robust over time. Ideally, a passive device design would provide the unique response behaviour of a semi-active device, but in a far more robust and low-cost device. This study presents the design, development and characterization of a passive Direction and Displacement Dependent viscous damping (D3) device. It can provide viscous damping in any single quadrant of the force-displacement hysteresis loop and any two in combination. Previously, this behaviour could only be obtained with a semi-active device. The D3 device is developed from a typical viscous damper, which is tested to evaluate the baseline of orifice sizing, force levels and velocity dependence. This prototype viscous damper is then modified in clear steps to produce a device with the desired single quadrant hysteresis loop. The overall results provide the design approach, device characterization and validation for this novel device design.","PeriodicalId":46396,"journal":{"name":"Bulletin of the New Zealand Society for Earthquake Engineering","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43855677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-06-30DOI: 10.5459/BNZSEE.51.2.85-91
N. Ismail, T. El-Maaddawy, A. Najmal, N. Khattak
Masonry infilled reinforced concrete frame buildings built prior to the introduction of modern seismic provisions have been observed to undergo damage in and around the masonry infill walls during most recent moderate to severe earthquakes. Fibre reinforced cementitious matrix (FRCM) is one of several retrofitting options available to limit such earthquake induced damage to infill walls. An experimental program was undertaken herein to experimentally investigate the effectiveness of FRCM as a strengthening solution for vintage (i.e. built between 1880 and 1930) un-reinforced brick masonry (URM) and insulated concrete masonry (IMU) infill walls. A total of 16 masonry assemblages were tested under in-plane diagonal load, of these 8 were constructed replicating vintage URM whereas the remainder were constructed using modern IMU. IMU is a preferred masonry type in hot and humid regions owing to its superior insulting capability. Different polymer fabrics (i.e., carbon, glass and basalt) were applied over both faces of test walls, with two replicate test walls receiving the same FRCM strengthening details. One test wall of each masonry type was tested as-built to serve as a control specimen for comparison. One wall of each masonry type received two layers of basalt FRCM. The investigated aspects included stress-strain behaviour, stiffness, and ductility. Shear strength increment observed due to single layer of FRCM application was 422-778% for vintage URM and 307-415% for modern IMU. FRCM also substantially increased the ductility capacity of the masonry assemblages.
{"title":"Experimental in-plane performance of insulated concrete and brick masonry wall panels retrofitted using polymer composites","authors":"N. Ismail, T. El-Maaddawy, A. Najmal, N. Khattak","doi":"10.5459/BNZSEE.51.2.85-91","DOIUrl":"https://doi.org/10.5459/BNZSEE.51.2.85-91","url":null,"abstract":"Masonry infilled reinforced concrete frame buildings built prior to the introduction of modern seismic provisions have been observed to undergo damage in and around the masonry infill walls during most recent moderate to severe earthquakes. Fibre reinforced cementitious matrix (FRCM) is one of several retrofitting options available to limit such earthquake induced damage to infill walls. An experimental program was undertaken herein to experimentally investigate the effectiveness of FRCM as a strengthening solution for vintage (i.e. built between 1880 and 1930) un-reinforced brick masonry (URM) and insulated concrete masonry (IMU) infill walls. A total of 16 masonry assemblages were tested under in-plane diagonal load, of these 8 were constructed replicating vintage URM whereas the remainder were constructed using modern IMU. IMU is a preferred masonry type in hot and humid regions owing to its superior insulting capability. Different polymer fabrics (i.e., carbon, glass and basalt) were applied over both faces of test walls, with two replicate test walls receiving the same FRCM strengthening details. One test wall of each masonry type was tested as-built to serve as a control specimen for comparison. One wall of each masonry type received two layers of basalt FRCM. The investigated aspects included stress-strain behaviour, stiffness, and ductility. Shear strength increment observed due to single layer of FRCM application was 422-778% for vintage URM and 307-415% for modern IMU. FRCM also substantially increased the ductility capacity of the masonry assemblages.","PeriodicalId":46396,"journal":{"name":"Bulletin of the New Zealand Society for Earthquake Engineering","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2018-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43692039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-12-31DOI: 10.5459/BNZSEE.43.4.374-381
M. Anagnostopoulou, M. Bruneau, H. Gavin
This paper focuses on the structural behaviour and types of failure of churches located in the general Canterbury area following the Darfield earthquake of September 04, 2010. Given the variability in architectural styles, structural systems and properties of underlying soils, different patterns of damage were identified including out-of-plane gable failures, collapse of bell towers and cracking due to liquefaction and ground settlement. An architectural and historical landmark of Christchurch, the Christchurch Cathedral, suffered insignificant damage during the earthquake mainly because of its seismic retrofitting during 2006-2007. However many other church structures required retrofitting and supporting measures to avoid additional damage.
{"title":"Performance of churches during the Darfield earthquake of September 4, 2010","authors":"M. Anagnostopoulou, M. Bruneau, H. Gavin","doi":"10.5459/BNZSEE.43.4.374-381","DOIUrl":"https://doi.org/10.5459/BNZSEE.43.4.374-381","url":null,"abstract":"This paper focuses on the structural behaviour and types of failure of churches located in the general Canterbury area following the Darfield earthquake of September 04, 2010. Given the variability in architectural styles, structural systems and properties of underlying soils, different patterns of damage were identified including out-of-plane gable failures, collapse of bell towers and cracking due to liquefaction and ground settlement. \u0000An architectural and historical landmark of Christchurch, the Christchurch Cathedral, suffered insignificant damage during the earthquake mainly because of its seismic retrofitting during 2006-2007. However many other church structures required retrofitting and supporting measures to avoid additional damage.","PeriodicalId":46396,"journal":{"name":"Bulletin of the New Zealand Society for Earthquake Engineering","volume":"43 1","pages":"374-381"},"PeriodicalIF":1.7,"publicationDate":"2010-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70852403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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