Pub Date : 2016-06-30DOI: 10.5459/BNZSEE.49.2.211-232
D. Dizhur, R. Dhakal, J. Bothara, J. Ingham
Nepal is one of the most earthquake-prone countries in the world, and at the same time is one of the most economically deprived. On 25 April 2015 mid-western Nepal was hit by the devastating Gorkha earthquake measuring Mw 7.8 with the epicentre located 76 km north-west of Kathmandu. The earthquake was followed by a series of aftershocks, with the most significant occurring on 12 May 2015 with Mw 7.3 and an epicentre located north-east of Kathmandu. The earthquake and the associated aftershocks resulted in the destruction of half a million buildings, leaving millions of people homeless and causing a loss of more than $3.5 billion (USD) to the housing sector alone. Approximately 9,000 people were killed and over 23,000 people were injured - mostly due to damaged or collapsed buildings. A number of documents have been published pertaining to general observations following the 2015 Gorkha earthquake and aftershocks. Here the common building typologies and related failure modes observed during inspection surveys by the authors who were part of the various reconnaissance teams following the earthquakes are summarised. A brief background on the 2015 Gorkha earthquake is provided with an outline of the tectonic environment and seismological background of Nepal and a brief summary of previous earthquake activities in the region is presented. Common construction practices identified during the reconnaissance are illustrated and briefly explained to provide context to the observed earthquake damage, with an emphasis placed on unreinforced masonry (URM) building typologies and construction practices. Comparisons between URM building damage and published macro-element failure modes are provided using various photographic and schematic examples. Commonly observed failure modes and potential causes of failure are also highlighted for buildings constructed of reinforced concrete (RC) frames with masonry infill. A brief review of adopted temporary shoring techniques is also included.
{"title":"Building typologies and failure modes observed in the 2015 Gorkha (Nepal) earthquake","authors":"D. Dizhur, R. Dhakal, J. Bothara, J. Ingham","doi":"10.5459/BNZSEE.49.2.211-232","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.2.211-232","url":null,"abstract":"Nepal is one of the most earthquake-prone countries in the world, and at the same time is one of the most economically deprived. On 25 April 2015 mid-western Nepal was hit by the devastating Gorkha earthquake measuring Mw 7.8 with the epicentre located 76 km north-west of Kathmandu. The earthquake was followed by a series of aftershocks, with the most significant occurring on 12 May 2015 with Mw 7.3 and an epicentre located north-east of Kathmandu. The earthquake and the associated aftershocks resulted in the destruction of half a million buildings, leaving millions of people homeless and causing a loss of more than $3.5 billion (USD) to the housing sector alone. Approximately 9,000 people were killed and over 23,000 people were injured - mostly due to damaged or collapsed buildings. \u0000A number of documents have been published pertaining to general observations following the 2015 Gorkha earthquake and aftershocks. Here the common building typologies and related failure modes observed during inspection surveys by the authors who were part of the various reconnaissance teams following the earthquakes are summarised. A brief background on the 2015 Gorkha earthquake is provided with an outline of the tectonic environment and seismological background of Nepal and a brief summary of previous earthquake activities in the region is presented. Common construction practices identified during the reconnaissance are illustrated and briefly explained to provide context to the observed earthquake damage, with an emphasis placed on unreinforced masonry (URM) building typologies and construction practices. Comparisons between URM building damage and published macro-element failure modes are provided using various photographic and schematic examples. Commonly observed failure modes and potential causes of failure are also highlighted for buildings constructed of reinforced concrete (RC) frames with masonry infill. A brief review of adopted temporary shoring techniques is also included.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129726216","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 : 2016-06-30DOI: 10.5459/BNZSEE.49.2.200-210
C. Y. Chin, C. Kayser, M. Pender
This paper provides results from carrying out two-dimensional dynamic finite element analyses to determine the applicability of simple pseudo-static analyses for assessing seismic earth forces acting on embedded cantilever and propped retaining walls appropriate for New Zealand. In particular, this study seeks to determine if the free-field Peak Ground Acceleration (PGAff) commonly used in these pseudo-static analyses can be optimized. The dynamic finite element analyses considered embedded cantilever and propped walls in shallow (Class C) and deep (Class D) soils (NZS 1170.5:2004). Three geographical zones in New Zealand were considered. A total of 946 finite element runs confirmed that optimized seismic coefficients based on fractions of PGAff can be used in pseudo-static analyses to provide moderately conservative estimates of seismic earth forces acting on retaining walls. Seismic earth forces were found to be sensitive to and dependent on wall displacements, geographical zones and soil classes. A reclassification of wall displacement ranges associated with different geographical zones, soil classes and each of the three pseudo-static methods of calculations (Rigid, Stiff and Flexible wall pseudo-static solutions) is presented. The use of different ensembles of acceleration-time histories appropriate for the different geographic zones resulted in significantly different calculated seismic earth forces, confirming the importance of using geographic-specific motions. The recommended location of the total dynamic active force (comprising both static and dynamic forces) for all cases is 0.7H from the top of the wall (where H is the retained soil height).
{"title":"Seismic earth forces against embedded retaining walls","authors":"C. Y. Chin, C. Kayser, M. Pender","doi":"10.5459/BNZSEE.49.2.200-210","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.2.200-210","url":null,"abstract":"This paper provides results from carrying out two-dimensional dynamic finite element analyses to determine the applicability of simple pseudo-static analyses for assessing seismic earth forces acting on embedded cantilever and propped retaining walls appropriate for New Zealand. In particular, this study seeks to determine if the free-field Peak Ground Acceleration (PGAff) commonly used in these pseudo-static analyses can be optimized. The dynamic finite element analyses considered embedded cantilever and propped walls in shallow (Class C) and deep (Class D) soils (NZS 1170.5:2004). Three geographical zones in New Zealand were considered. A total of 946 finite element runs confirmed that optimized seismic coefficients based on fractions of PGAff can be used in pseudo-static analyses to provide moderately conservative estimates of seismic earth forces acting on retaining walls. Seismic earth forces were found to be sensitive to and dependent on wall displacements, geographical zones and soil classes. A reclassification of wall displacement ranges associated with different geographical zones, soil classes and each of the three pseudo-static methods of calculations (Rigid, Stiff and Flexible wall pseudo-static solutions) is presented. The use of different ensembles of acceleration-time histories appropriate for the different geographic zones resulted in significantly different calculated seismic earth forces, confirming the importance of using geographic-specific motions. The recommended location of the total dynamic active force (comprising both static and dynamic forces) for all cases is 0.7H from the top of the wall (where H is the retained soil height).","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131217773","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 : 2016-06-30DOI: 10.5459/BNZSEE.49.2.148-174
M. Giaretton, D. Dizhur, F. Porto, J. Ingham
Following the 2010/2011 Canterbury earthquakes considerable effort was applied to the task of developing industry guidance for the seismic assessment, repair and strengthening of unreinforced masonry buildings. The recently updated “Section 10” of NZSEE 2006 is one of the primary outputs from these efforts, in which a minor amount of information is introduced regarding vintage stone unreinforced masonry (URM) buildings. Further information is presented herein to extend the resources readily available to New Zealand practitioners regarding load-bearing stone URM buildings via a literature review of the traditional European approach to this topic and its applicability to the New Zealand stone URM building stock. An informative background to typical stone URM construction is presented, including population, geometric, structural and material characteristics. The European seismic vulnerability assessment procedure is then reported, explaining each step in sequence of assessment by means of preliminary inspection (photographic, geometric, structural and crack pattern surveys) and investigation techniques, concluding with details of seismic improvement interventions. The challenge in selecting the appropriate intervention for each existing URM structure is associated with reconciling the differences between heritage conservation and engineering perspectives to reinstating the original structural strength. Traditional and modern techniques are discussed herein with the goal of preserving heritage values and ensuring occupant safety. A collection of Annexes are provided that summarise the presented information in terms of on-site testing, failure mechanisms and seismic improvement.
{"title":"Seismic Assessment and Improvement of Unreinforced Stone Masonry Buildings: Literature Review and Application to New Zealand","authors":"M. Giaretton, D. Dizhur, F. Porto, J. Ingham","doi":"10.5459/BNZSEE.49.2.148-174","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.2.148-174","url":null,"abstract":"Following the 2010/2011 Canterbury earthquakes considerable effort was applied to the task of developing industry guidance for the seismic assessment, repair and strengthening of unreinforced masonry buildings. The recently updated “Section 10” of NZSEE 2006 is one of the primary outputs from these efforts, in which a minor amount of information is introduced regarding vintage stone unreinforced masonry (URM) buildings. Further information is presented herein to extend the resources readily available to New Zealand practitioners regarding load-bearing stone URM buildings via a literature review of the traditional European approach to this topic and its applicability to the New Zealand stone URM building stock. \u0000An informative background to typical stone URM construction is presented, including population, geometric, structural and material characteristics. The European seismic vulnerability assessment procedure is then reported, explaining each step in sequence of assessment by means of preliminary inspection (photographic, geometric, structural and crack pattern surveys) and investigation techniques, concluding with details of seismic improvement interventions. The challenge in selecting the appropriate intervention for each existing URM structure is associated with reconciling the differences between heritage conservation and engineering perspectives to reinstating the original structural strength. Traditional and modern techniques are discussed herein with the goal of preserving heritage values and ensuring occupant safety. A collection of Annexes are provided that summarise the presented information in terms of on-site testing, failure mechanisms and seismic improvement.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126508114","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 : 2016-06-30DOI: 10.5459/BNZSEE.49.2.175-189
P. K. Aninthaneni, R. Dhakal
The most important structural parameter in the estimation of the seismic demand on a building is the natural period of the building’s fundamental/first mode of vibration. There are several existing empirical, analytical, and experimental methods which can be used to estimate the fundamental period of a building. The empirical equations prescribed in the building codes are simple, but they do not consider actual building properties, and are very approximate. On the other hand, analytical methods like Eigenvalue analysis and Rayleigh method are able to consider most of the structural parameters that are known to affect the period of a building. Nevertheless, the analytical methods require considerable effort and expertise; often requiring structural analysis software’s to estimate the fundamental period of a building. In this paper, a generic method is developed to estimate the fundamental period of regular frame buildings and a simple yet reliable equation is proposed. The equation is derived using the basic concept of MacLeod’s method for estimation of roof/top deflection of a frame building, which is modified to more accurately predict the lateral stiffness of moment resisting frames under triangular lateral force distribution typically used in seismic design and analysis of frame buildings. To verify the reliability and versatility of the developed equation, the fundamental periods predicted are compared with the periods obtained from Eigenvalue analysis for a large number of low to medium rise RC frame buildings. The fundamental period predicted using the proposed equation is also verified using the period obtained using the Rayleigh method and measured in experimental tests. Since the proposed equation was found to closely predict the fundamental period, the results are used to study the limitations of the empirical equations prescribed in building codes. The applicability of the proposed equation to predict the fundamental period of low to medium rise frame buildings with minor irregularity is also investigated, and it was found that the proposed equation can be used for slightly irregular frame buildings without inducing any additional error. The proposed equation is simple enough to be implemented into building design codes and can be readily used by practicing engineers in design of new buildings as well as assessment of existing buildings.
{"title":"Prediction of fundamental period of regular frame buildings","authors":"P. K. Aninthaneni, R. Dhakal","doi":"10.5459/BNZSEE.49.2.175-189","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.2.175-189","url":null,"abstract":"The most important structural parameter in the estimation of the seismic demand on a building is the natural period of the building’s fundamental/first mode of vibration. There are several existing empirical, analytical, and experimental methods which can be used to estimate the fundamental period of a building. The empirical equations prescribed in the building codes are simple, but they do not consider actual building properties, and are very approximate. On the other hand, analytical methods like Eigenvalue analysis and Rayleigh method are able to consider most of the structural parameters that are known to affect the period of a building. Nevertheless, the analytical methods require considerable effort and expertise; often requiring structural analysis software’s to estimate the fundamental period of a building. \u0000In this paper, a generic method is developed to estimate the fundamental period of regular frame buildings and a simple yet reliable equation is proposed. The equation is derived using the basic concept of MacLeod’s method for estimation of roof/top deflection of a frame building, which is modified to more accurately predict the lateral stiffness of moment resisting frames under triangular lateral force distribution typically used in seismic design and analysis of frame buildings. To verify the reliability and versatility of the developed equation, the fundamental periods predicted are compared with the periods obtained from Eigenvalue analysis for a large number of low to medium rise RC frame buildings. The fundamental period predicted using the proposed equation is also verified using the period obtained using the Rayleigh method and measured in experimental tests. Since the proposed equation was found to closely predict the fundamental period, the results are used to study the limitations of the empirical equations prescribed in building codes. The applicability of the proposed equation to predict the fundamental period of low to medium rise frame buildings with minor irregularity is also investigated, and it was found that the proposed equation can be used for slightly irregular frame buildings without inducing any additional error. The proposed equation is simple enough to be implemented into building design codes and can be readily used by practicing engineers in design of new buildings as well as assessment of existing buildings.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121320901","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 : 2016-03-31DOI: 10.5459/BNZSEE.49.1.79-85
Helen Ferner, R. Jury, A. King, M. Wemyss, A. Baird
The recent earthquakes in New Zealand have raised awareness of the seismic vulnerability of non-structural elements and the costly consequences when non-structural elements perform poorly. Impacts on business continuity due to the damage of non-structural elements has been identified as a major cost and disruption issue in recent earthquakes in New Zealand, as well as worldwide. Clearly improvements in performance of non-structural elements under earthquake loads will yield benefits to society. This paper explores the intended and expected performance objectives for non-structural elements. Possible historic differences in performance objective expectations for non-structural elements between building services engineers, fire engineers and structural engineers are discussed. Wider construction industry expectations are explored along with our experience of client and regulatory authority views. The paper discusses the application and interpretation of the New Zealand earthquake loadings Standard NZS1170.5:2004 for the design of non-structural elements including possible differences in interpretation between building services, structural and fire engineers leading to confusion around the expected performance of non-structural elements under different limit states. It is based on the experience of several of the authors as members of the Standards committee for NZS1170.5:2004. The paper concludes by discussing changes to NZS1170.5:2004 the authors have proposed as members of the NZS1170.5 Standards committee to clarify and address the identified issues. These changes clarify the classification of parts, requirements for consideration earthquake imposed deformations, parts supported on ledges, potential falling of parts, the combination of fire and earthquake loads, and the requirement for parts to be designed for both serviceability and ultimate limit states along with the effective introduction of a serviceability limit state for parts for occupational continuity.
{"title":"Performance objectives for non-structural elements","authors":"Helen Ferner, R. Jury, A. King, M. Wemyss, A. Baird","doi":"10.5459/BNZSEE.49.1.79-85","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.1.79-85","url":null,"abstract":"The recent earthquakes in New Zealand have raised awareness of the seismic vulnerability of non-structural elements and the costly consequences when non-structural elements perform poorly. Impacts on business continuity due to the damage of non-structural elements has been identified as a major cost and disruption issue in recent earthquakes in New Zealand, as well as worldwide. Clearly improvements in performance of non-structural elements under earthquake loads will yield benefits to society. \u0000This paper explores the intended and expected performance objectives for non-structural elements. Possible historic differences in performance objective expectations for non-structural elements between building services engineers, fire engineers and structural engineers are discussed. Wider construction industry expectations are explored along with our experience of client and regulatory authority views. \u0000The paper discusses the application and interpretation of the New Zealand earthquake loadings Standard NZS1170.5:2004 for the design of non-structural elements including possible differences in interpretation between building services, structural and fire engineers leading to confusion around the expected performance of non-structural elements under different limit states. It is based on the experience of several of the authors as members of the Standards committee for NZS1170.5:2004. \u0000The paper concludes by discussing changes to NZS1170.5:2004 the authors have proposed as members of the NZS1170.5 Standards committee to clarify and address the identified issues. These changes clarify the classification of parts, requirements for consideration earthquake imposed deformations, parts supported on ledges, potential falling of parts, the combination of fire and earthquake loads, and the requirement for parts to be designed for both serviceability and ultimate limit states along with the effective introduction of a serviceability limit state for parts for occupational continuity.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127139623","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 : 2016-03-31DOI: 10.5459/bnzsee.49.1.116-124
D. Wang, J. Dai, X. Ning
Earthquakes have again highlighted the vulnerability of China’s health facilities. The current investigation of the seismic status of hospital facilities was conducted after the Lushan MW6.6 earthquake, and both structural and nonstructural damage are listed. Structural and nonstructural damage of four typical hospitals and clinics are discussed here. Structural damage is here described alongside damage to architectural elements, equipment, and furnishings caused by earthquakes. This investigation indicated that the hospital facilities can lose partial or full functionality due to nonstructural damage or even limited structural damage. Although none of the objects inside were knocked over and only a few decorations fell down, many sets of equipment were severely damaged because of the strong floor vibration. This resulted in great economic losses and delays in rescue operations after the earthquake. Shaking table tests on a full scale model of a B-ultrasound room were conducted to investigate the seismic performance of a typical room in a hospital. The tests results showed that the acceleration responses of the building contents with or without trundles demonstrated different behaviour. Without trundles, the peak acceleration and the peak displacement of building contents first increased with increasing PGA and then decreased when the acceleration exceeded a particular value. Then they both changed a little. Because of the rapid turning trundles, the response of building contents increased only slightly as PGA increased, or even decreased or remained roughly steady. INTRODUCTION Health care facilities are expected to remain functional during and after earthquakes. However, investigations have shown that health care facilities are more vulnerable to earthquakes than other types of buildings. Seismic damage to health care facilities results in interruption of hospital facilities immediately even after the moderate earthquake [1]. The MW8.8 Chile earthquake of February 27, 2010 caused significant nonstructural damage. According to the Ministry of Health of Chile, 71% of the public hospitals were located in the affected areas, providing 63% of the country’s total beds. Of these hospitals, 62% suffered nonstructural damage necessitating some repairs. Of the damaged hospitals that were partially or completely closed after the earthquake, 83% lost partial or total functionality because of nonstructural damage. Some of the hospitals suffered various levels of structural damage, most of which was minor to moderate, with an extremely small portion being severe [2]. The nonstructural components of hospitals in the three counties stricken by the MW9.0 Great East Japan Earthquake on March 11, 2011 performed poorly after the earthquake. Out of the 381 hospitals considered in this study, 8 hospitals suffered from complete destruction of equipment, and 179 hospitals suffered from partial damage to equipment. In particular, in all the 147 hospitals in Miyagi-ken,
{"title":"Shaking table tests of typical B-ultrasound model hospital room in a simulation of the Lushan earthquake","authors":"D. Wang, J. Dai, X. Ning","doi":"10.5459/bnzsee.49.1.116-124","DOIUrl":"https://doi.org/10.5459/bnzsee.49.1.116-124","url":null,"abstract":"Earthquakes have again highlighted the vulnerability of China’s health facilities. The current investigation of the seismic status of hospital facilities was conducted after the Lushan MW6.6 earthquake, and both structural and nonstructural damage are listed. Structural and nonstructural damage of four typical hospitals and clinics are discussed here. Structural damage is here described alongside damage to architectural elements, equipment, and furnishings caused by earthquakes. This investigation indicated that the hospital facilities can lose partial or full functionality due to nonstructural damage or even limited structural damage. Although none of the objects inside were knocked over and only a few decorations fell down, many sets of equipment were severely damaged because of the strong floor vibration. This resulted in great economic losses and delays in rescue operations after the earthquake. Shaking table tests on a full scale model of a B-ultrasound room were conducted to investigate the seismic performance of a typical room in a hospital. The tests results showed that the acceleration responses of the building contents with or without trundles demonstrated different behaviour. Without trundles, the peak acceleration and the peak displacement of building contents first increased with increasing PGA and then decreased when the acceleration exceeded a particular value. Then they both changed a little. Because of the rapid turning trundles, the response of building contents increased only slightly as PGA increased, or even decreased or remained roughly steady. INTRODUCTION Health care facilities are expected to remain functional during and after earthquakes. However, investigations have shown that health care facilities are more vulnerable to earthquakes than other types of buildings. Seismic damage to health care facilities results in interruption of hospital facilities immediately even after the moderate earthquake [1]. The MW8.8 Chile earthquake of February 27, 2010 caused significant nonstructural damage. According to the Ministry of Health of Chile, 71% of the public hospitals were located in the affected areas, providing 63% of the country’s total beds. Of these hospitals, 62% suffered nonstructural damage necessitating some repairs. Of the damaged hospitals that were partially or completely closed after the earthquake, 83% lost partial or total functionality because of nonstructural damage. Some of the hospitals suffered various levels of structural damage, most of which was minor to moderate, with an extremely small portion being severe [2]. The nonstructural components of hospitals in the three counties stricken by the MW9.0 Great East Japan Earthquake on March 11, 2011 performed poorly after the earthquake. Out of the 381 hospitals considered in this study, 8 hospitals suffered from complete destruction of equipment, and 179 hospitals suffered from partial damage to equipment. In particular, in all the 147 hospitals in Miyagi-ken,","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123632956","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 : 2016-03-31DOI: 10.5459/bnzsee.49.1.1-12
Zhen-Yu Lin, F. Lin, J. Chai, Kuo-Chun Chang
Based on the issue of life safety and immediate needs of emergency medical services provided by hospitals after strong earthquakes, this paper aims to introduce a research programme on assessment and improvement strategies for a typical configuration of sprinkler piping systems in hospitals. The study involved component tests and subsystem tests. Cyclic loading tests were conducted to investigate the inelastic behaviour of components including concrete anchorages, screwed fittings of small-bore pipes and couplings. Parts of a horizontal piping system of a seismic damaged sprinkler piping system were tested using shaking table tests. Furthermore, horizontal piping subsystems with seismic resistant devices such as braces, flexible pipes and couplings were also tested. The test results showed that the main cause of damage was the poor capacity of a screwed fitting of the small-bore tee branch. The optimum improvement strategy to achieve a higher nonstructural performance level for the horizontal piping subsystem is to strengthen the main pipe with braces and decrease moment demands on the tee branch by the use of flexible pipes. The hysteresis loops and failure modes of components were further discussed and will be used to conduct numerical analysis of sprinkler piping systems in future studies.
{"title":"Experimental studies of a typical sprinkler piping system in hospitals","authors":"Zhen-Yu Lin, F. Lin, J. Chai, Kuo-Chun Chang","doi":"10.5459/bnzsee.49.1.1-12","DOIUrl":"https://doi.org/10.5459/bnzsee.49.1.1-12","url":null,"abstract":"Based on the issue of life safety and immediate needs of emergency medical services provided by hospitals after strong earthquakes, this paper aims to introduce a research programme on assessment and improvement strategies for a typical configuration of sprinkler piping systems in hospitals. The study involved component tests and subsystem tests. Cyclic loading tests were conducted to investigate the inelastic behaviour of components including concrete anchorages, screwed fittings of small-bore pipes and couplings. Parts of a horizontal piping system of a seismic damaged sprinkler piping system were tested using shaking table tests. Furthermore, horizontal piping subsystems with seismic resistant devices such as braces, flexible pipes and couplings were also tested. The test results showed that the main cause of damage was the poor capacity of a screwed fitting of the small-bore tee branch. The optimum improvement strategy to achieve a higher nonstructural performance level for the horizontal piping subsystem is to strengthen the main pipe with braces and decrease moment demands on the tee branch by the use of flexible pipes. The hysteresis loops and failure modes of components were further discussed and will be used to conduct numerical analysis of sprinkler piping systems in future studies.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134573985","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 : 2016-03-31DOI: 10.5459/BNZSEE.49.1.45-63
R. Dhakal, G. MacRae, A. Pourali, G. Paganotti
Current standards and guidelines for the design and installation of perimeter-fixed suspended ceilings are briefly reviewed and a summary of common damage in recent earthquakes is provided. Component failure fragility curves have been derived following experiments on typical NZ suspended ceilings, considering loading in tension, compression and shear. A simple method to analyse perimeter-fixed ceilings using peak floor acceleration (PFA) is described, allowing for ceiling system fragility to be obtained from component fragilities. This is illustrated in an example of a 5 storey building. It was found that single rivet end-fixings and cross-tee connections were the most critical elements of the ceilings governing the system capacity. In the design examples it was shown that ceilings at different elevations of the structure showed different probabilities of failure and larger ceiling areas with heavier tiles were most susceptible to damage.
{"title":"Seismic fragility of suspended ceiling systems used in NZ based on component tests","authors":"R. Dhakal, G. MacRae, A. Pourali, G. Paganotti","doi":"10.5459/BNZSEE.49.1.45-63","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.1.45-63","url":null,"abstract":"Current standards and guidelines for the design and installation of perimeter-fixed suspended ceilings are briefly reviewed and a summary of common damage in recent earthquakes is provided. Component failure fragility curves have been derived following experiments on typical NZ suspended ceilings, considering loading in tension, compression and shear. A simple method to analyse perimeter-fixed ceilings using peak floor acceleration (PFA) is described, allowing for ceiling system fragility to be obtained from component fragilities. This is illustrated in an example of a 5 storey building. It was found that single rivet end-fixings and cross-tee connections were the most critical elements of the ceilings governing the system capacity. In the design examples it was shown that ceilings at different elevations of the structure showed different probabilities of failure and larger ceiling areas with heavier tiles were most susceptible to damage.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130948128","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 : 2016-03-31DOI: 10.5459/BNZSEE.49.1.13-21
J. Chai, Tzu-Chieh Chien, F. Lin, Zen-Yu Lin, Jian-Xiang Wang, Jenn‐Shin Hwang
From the experience gained from recent earthquakes, it has been recognized that the earthquake resisting capacity of so-called responsibility hospitals for acute services in Taiwan should be upgraded. These hospitals, which have been tasked with the provision of emergency services after major earthquakes, should remain functional with regard to their structures, medical facilities, electricity and water supply, and information services. In order to facilitate the issuing of governmental policies and practical engineering services regarding the seismic upgrading of hospitals, the objective of this paper is to determine the seismic rehabilitation objectives of essential medical equipment and nonstructural components in responsibility hospitals, and further, to propose seismic evaluation and strengthening guidelines. Owing to the onerous work required to improve the seismic performance of various nonstructural components, a simplified programme is established using Microsoft Excel software to execute a preliminary seismic evaluation and retrofit design for individual pieces of medical equipment. Users are asked to fill in blanks with hospital information and the parameters of selected equipment and then the programme identifies the performance objective of each piece of equipment. It also determines whether the equipment should be retrofitted or not. In addition, preliminary designs of post-installation anchor bolts for seismic retrofitting against specified seismic demands can be checked automatically by the programme.
{"title":"Seismic rehabilitation objectives and a simplified seismic evaluation and design programme for medical equipment in hospitals","authors":"J. Chai, Tzu-Chieh Chien, F. Lin, Zen-Yu Lin, Jian-Xiang Wang, Jenn‐Shin Hwang","doi":"10.5459/BNZSEE.49.1.13-21","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.1.13-21","url":null,"abstract":"From the experience gained from recent earthquakes, it has been recognized that the earthquake resisting capacity of so-called responsibility hospitals for acute services in Taiwan should be upgraded. These hospitals, which have been tasked with the provision of emergency services after major earthquakes, should remain functional with regard to their structures, medical facilities, electricity and water supply, and information services. In order to facilitate the issuing of governmental policies and practical engineering services regarding the seismic upgrading of hospitals, the objective of this paper is to determine the seismic rehabilitation objectives of essential medical equipment and nonstructural components in responsibility hospitals, and further, to propose seismic evaluation and strengthening guidelines. Owing to the onerous work required to improve the seismic performance of various nonstructural components, a simplified programme is established using Microsoft Excel software to execute a preliminary seismic evaluation and retrofit design for individual pieces of medical equipment. Users are asked to fill in blanks with hospital information and the parameters of selected equipment and then the programme identifies the performance objective of each piece of equipment. It also determines whether the equipment should be retrofitted or not. In addition, preliminary designs of post-installation anchor bolts for seismic retrofitting against specified seismic demands can be checked automatically by the programme.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134472507","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 : 2016-03-31DOI: 10.5459/BNZSEE.49.1.64-78
R. Dhakal, A. Pourali, S. Saha
Post-disaster reconnaissance reports frequently list non-structural components (NSCs) as a major source of financial loss in earthquakes. Moreover, minimizing their damage is also of vital significance to the uninterrupted functionality of a building. For efficient decision making, it is important to be able to estimate the cost and downtime associated with the repair of the damage likely to be caused at different hazard levels used in seismic design. Generalized loss functions for two important NSCs commonly used in New Zealand, namely suspended ceilings and drywall partitions are developed in this study. The methodology to develop the loss functions, in the form of engineering demand parameter vs. expected loss due to the considered components, is based on the existing framework for the storey level loss estimation. Nevertheless, exhaustive construction/field data are employed to make these loss functions more generic. In order to estimate financial losses resulting from the failure of suspended ceilings, generalized ceiling fragility functions are developed and combined with the cost functions, which give the loss associated with typical ceilings at various peak acceleration demands. Similarly, probabilities of different damage states in drywall partitions are combined with their associated repair/replacement costs to find the cumulative distribution of the expected loss due to partitions at various drift levels, which is then normalized in terms of the total building cost. Efficiencies of the developed loss functions are investigated through detailed loss assessment of case study reinforced concrete (RC) buildings. It is observed that the difference between the expected losses for ceilings, predicted by the developed generic loss function, and the losses obtained from the detailed loss estimation method is within 5%. Similarly, the developed generic loss function for partitions is able to estimate the partition losses within 2% of that from the detailed loss assessment. The results confirm the accuracy of the proposed generic seismic loss functions.
{"title":"Simplified seismic loss functions for suspended ceilings and drywall partitions","authors":"R. Dhakal, A. Pourali, S. Saha","doi":"10.5459/BNZSEE.49.1.64-78","DOIUrl":"https://doi.org/10.5459/BNZSEE.49.1.64-78","url":null,"abstract":"Post-disaster reconnaissance reports frequently list non-structural components (NSCs) as a major source of financial loss in earthquakes. Moreover, minimizing their damage is also of vital significance to the uninterrupted functionality of a building. For efficient decision making, it is important to be able to estimate the cost and downtime associated with the repair of the damage likely to be caused at different hazard levels used in seismic design. Generalized loss functions for two important NSCs commonly used in New Zealand, namely suspended ceilings and drywall partitions are developed in this study. The methodology to develop the loss functions, in the form of engineering demand parameter vs. expected loss due to the considered components, is based on the existing framework for the storey level loss estimation. Nevertheless, exhaustive construction/field data are employed to make these loss functions more generic. In order to estimate financial losses resulting from the failure of suspended ceilings, generalized ceiling fragility functions are developed and combined with the cost functions, which give the loss associated with typical ceilings at various peak acceleration demands. Similarly, probabilities of different damage states in drywall partitions are combined with their associated repair/replacement costs to find the cumulative distribution of the expected loss due to partitions at various drift levels, which is then normalized in terms of the total building cost. Efficiencies of the developed loss functions are investigated through detailed loss assessment of case study reinforced concrete (RC) buildings. It is observed that the difference between the expected losses for ceilings, predicted by the developed generic loss function, and the losses obtained from the detailed loss estimation method is within 5%. Similarly, the developed generic loss function for partitions is able to estimate the partition losses within 2% of that from the detailed loss assessment. The results confirm the accuracy of the proposed generic seismic loss functions.","PeriodicalId":343472,"journal":{"name":"Bulletin of the New Zealand National Society for Earthquake Engineering","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117224862","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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