Figure 1: Stadium Southland on the left, prior to the collapse (The Southland Times- Permission requested, pending approval)
Introduction
The Stadium Southland roof collapsed around noon on September 18, 2010. Construction of the stadium commenced in 1999 and was completed in 2000. The stadium, shown on the left side in Figure 1, served as an indoor sports facility and contained multipurpose community courts, event courts, a climbing wall and other state-of-the-art facilities for the Southland region. Invercargill, NZ suffered a heavy snowstorm of a 1 in 250 year snow design level that was suspected as causing unusually high loads on the steel tube truss roof. There was no injury or loss of life resulting from the collapse. The roof collapse was thought to have been caused by the heavy snowfall that took place (Otago Daily Times Staff, 2010). After thorough investigation, it was concluded that the roof collapsed due to a combination of factors in addition to the snow loading from the heavy snowfall (Smith and Hyland, 2012). Some of the other factors that contributed to the collapse are design changes, defects in construction, and poor workmanship.
Following the collapse, the roof was redesigned incorporating better safety features and increased load capacity; other affected areas within the facility were also rebuilt. The stadium has been improved to a world-class venue. It reopened May 9, 2014 and was renamed ILT Stadium Southland. It continues to host various events and shows it also provides recreational and sporting facilities to the Southland region.
Key Words
Steel Trusses, Large Span Roof, Snow Loading, and Welds.
Stadium Description
Stadium Southland is located at Invercargill, New Ze
Figure 2: Model of Structural Frame (Photo courtesy DBH Final Investigation Report)
aland adjacent to the ILT Velodrome which is the oval shaped structure presented in Figure 1. Construction of Stadium Southland began in 1999, and was completed in seven months which was earlier than originally scheduled due to acceleration of the construction process. The velodrome was constructed a few years after the stadium and it opened May 2006. The two buildings are linked with a seismic joint that allows the velodrome and the stadium move independent of each other (Calder Stewart Construction, 2014). The original Stadium Southland was constructed for $10 million. Stadium Southland has a total area of 98038 ft2 (9108 m2) and the roof structure consists of long span hollow steel trusses. The trusses comprised square hollow sections and rectangular hollow sections with long spans of about 120 ft. (36.6 m); the roof comprised 0.02 in (0.55 mm) thick profiled metal sheet cladding, on safety netting and building paper (Smith and Hyland 2012, pp 22). The trusses supported the proprietary cold formed steel purlins with two lines of purlin braces in each bay. The purlins above the community courts spanned east to west and north to south above the event courts. Figure 2, created by Smith and Hyland (2012), shows a 3D model representation of the structural frame of the roof with the trusses above the community courts ( towards the south) and the events courts (towards the north). Some of the trusses were supported on concrete columns and others had part height concrete wall panels with steel framing.
Events Leading up to the Collapse
While the building was under construction, excessive deflections were detected in the steel roof trusses above the community courts. The trusses were noticeably sagging and the problem had to be corrected (Southland Times, 2012). Remedial work was carried out while the structure was still under construction in year 2000 to address the structural issues with the roof trusses and the connections including some measures which were taken to correct the deflections. The deflections were caused by design changes that were made during construction to reduce the steel quantities in some of the steel trusses of the community courts. Specifically, changes were made to the design capacity of the community court trusses, the connections to the south wall columns, the connections of the spine trusses to their supporting columns and cracking in the spine steel truss (Smith and Hyland 2012, pp 15). Even though these deflections were addressed, there were questions of whether remedial works were undertaken correctly and if the design elements met the loading requirements of the New Zealand building codes. Also in 2006, there was movement in the roof line of the stadium where the trusses spanned the community courts (Baker, 2010). The roof structure was reviewed by the secondary consulting engineer who said the trusses were adequate enough to support the loads (Heaney & McElroys, 2014). Nothing was done at that time to correct this concern since the roof was deemed safe. The roof held up till four years later when it collapsed under heavy snow. The severe snow storm that took place in Invercargill NZ caused damage to some other buildings in the Invercargill area. Most of the snowfall was thought to have taken place from 8pm Sept 17, 2010 to noon Sept 18, 2010. The National Institute of Water and Atmospheric research (NIWA) reported the average ground snow was 0.45 kPa (9.4 lb/ft2) and roof snow load at the time of the collapse was estimated to be 0.30 kPa (6.27 lb/ft2). The allowable roof snow load for the design was 0.47 kPa (9.82 lb/ft2) (Hendrikx 2010, pp 10).
Investigation into Causes of the Collapse
Before the investigation was conducted for the Department of Building and Housing (DBH) to determine the causes of the collapse of Stadium Southland, the structural evaluation of the structure was carried out so the cause of the collapse can be determined through structural analysis using the applicable design standards in New Zealand for the time the structure was designed. The investigation uncovered several problems with the design and construction of the stadium (Smith and Hyland, 2012). The full investigation report can be found here. The results of the technical investigation showed that in addition to the heavy snow fall, a number of other factors contributed to the collapse of the stadium as listed below.
Heavy snowfall
Although it was an unusual snow event, the National Institute of Water and Atmospheric research (NIWA) reported that the average ground snow and roof snow load did not exceed the allowable design snow load (Hendrikx, 2010). From the analysis of the snow loading it can be inferred that the heavy snow could not have been solely responsible for the failure.
Construction Defects
Some aspects of the steel fabrication were not compliant with the drawings. There were defects in connection of elements, welding and installation of strengthening and end bearing plates. Some of the connections to the concrete wall were brittle with missing connection bolts. Some of the steel truss members had less thickness than was required to reduce cost.
Design and Detailing issues
There were problems with the steel shear reinforcement in some of the columns supporting the main roof spine trusses and splices were located at highly loaded areas of the steel trusses above the community courts. There were some design modifications made that were too late to be implemented during construction.
Problems with Remedial Works
There were errors in calculating the loading used for the changes made related to remedial works and design changes were implemented late into the construction. Although the design changes for the remedial works was peer reviewed by a secondary consulting engineer there were still a lot of problems with the design, the same consulting engineer also cleared the roof as being safe when the sagging trusses above the community courts were noticed in 2006 (Heany et al. 2014).
Site Supervision
Some of the design and construction errors would have not been missed if site supervision was thorough (Bach 2012). There were also cases of non-compliance where on site steel fabrication and welding for remedial works were not compliant with design drawings (DBH, 2012a, pp 8), the spacing of reinforcing ties with columns was also less than required by standards. The police was invited to investigate the collapse following the release of the investigation report due to the level of non compliance of the construction (HERA, 2014). The consulting engineer for the project had to take responsibility for his negligence and was expelled from the institution of Professional Engineers New Zealand (IPENZ) for breaching the code of ethics and for his failure to carry out his professional engineering obligations (Hasell et al. 2014, pp 15). The engineer's action was a risk to the public and it was rather fortunate that there was no injury or loss of life resulting from the collapse. Kliment (1981) highlighted the importance of architect and engineer involvement in the construction process, the errors that were made could have been identified and corrected early on if site supervision and inspections were thorough.
Sequence of Collapse
According to the investigation report prepared for DBH, Stadium Southland collapse started at the mid-span to chord site splice in Truss T1 which caused the roof to be was displaced after similar compression failure occurred in nearby trusses T2-T5 above the community courts. The connected spine trusses were also displaced along with the column supports causing the failure to propagate through the structure and damage most of the roof. The collapse sequence diagram outlining the collapsed members as provided in the DBH report is presented in Figure 3 below (Smith and Hyland, 2012, pp 49-50). The damage at the roof level of the community courts and walls are shown in Figures 4, 5 and 6.
Figure 3: Collapse Sequence (Photo Courtesy of DBH Final Investigation Report)
It was reported that when the collapse occurred some tennis players were just leaving the stadium and there was one person in the building. They reported that they heard a loud bang and one of the doors to the community courts burst open, there was also flying debris of a roof panel (Smith and Hyland 2012, pp 33). Luckily when the collapse occurred no one was injured. There was extensive damage to the roof above the community courts and the event courts, portions of the end walls on the eastern and western side of the stadium were damaged and the main roof spine truss and column supporting events courts and community courts failed. The purlins were also damaged as a result of the collapse. ILT Velodrome, which is adjacent to Stadium Southland was unaffected and the structure remained intact after the heavy snow event.
Figure 4: Damage at the Community Court Roof (Photo Courtesy DBH Final Investigation Report)
Figure 5: Extent of Damage at the North side of the Stadium (Photo courtesy www.weatherwatch.co.nz)
Figure 6: Extent of damage at the East side of the roof (Photo courtesy of www.weatherwatch.co.nz)
Figure 7: ILT Stadium Southland (Photo courtesy of www.stadiumsouth.co.nz)
Reconstruction of the Stadium
Stadium Southland was rebuilt and renamed ILT Stadium Southland and opened in May 9, 2014. The building size was only slightly increased to 107639 ft2 (10000 m2) but has larger sitting capacity. The cost of rebuilding the stadium was $43 million NZD, which is significantly higher than the cost of the previous stadium which was $10 million NZD, the new stadium was built by the same contractors that constructed the former stadium (ABL, 2014). The insurance paid about $20 million NZD of the reconstruction cost.Reconstruction started in March 2011 and the building was initially scheduled to be completed in March 2012 but was late by about 2 years and was completed in February 2014. The Christchurch earthquake that occurred in February 2011 was one of the factors that delayed the project. Design changes were made to strengthen the structure and improve the redundancy of the building following the earthquake which also contributed to the increasing cost. The stadium was also upgraded, the construction was worth the wait and ILT stadium is classed as a world-class venue. The lessons learned from the failure were adhered to and a safer and structurally sound building was constructed.
Lessons Learned
The space frame roof of the Hartford Civic Center Coliseum collapsed in 1978, it bears some similarities to the Stadium Southland roof collapse. There were concerns about the excessive deflections that were observed in the steel space roof frame that was not corrected there were also some design and construction errors which contributed to the collapse of the building after five years (Johnson, 2009). The collapse of the Hartford Civic Center Coliseum brought about some changes in the design and construction of long span trusses by introducing peer review of structural design calculations (Ratay 2011, pp 2). Following the collapse of Stadium Southland roof, several recommendations were made to the Department of Building and Housing. Some other recommendations made following investigation of the Christchurch earthquake were mostly implemented to improve the safety and redundancy of structures in New Zealand (DBH 2012b, pp 11-14). Some of the specific changes can be found in the Practice advisory for welding and section checks in long span steel roof trusses. The document provides guidelines for the inspection of roof trusses and weld connections. Some of the changes made in industry following the investigation were incorporated during the reconstruction of the stadium.
General Recommendations
When building failures occur and the failure has been investigated, recommendations are made to prevent reoccurrence, suggest improvements and implement changes that are beneficial to the design, building owners and to the industry. A summary of the recommendations which can be found in the report prepared for the Department of Building and Housing in New Zealand are presented below (DBH 2012a, pp 11-14). Some of these recommendations are also in line with some of the conclusions drawn from AIA in relation to checking design calulations (peer review) and making design decisions on the field (Kliment 1981, 2).
Existing long span roof trusses should be reviewed for adequacy, confirmation of updated inspection reports to ensure welding requirements are met
Buildings in snow prone regions with large spans should develop snow load monitoring, mitigation and evacuation procedures
Further research should be conducted to better understand snow loading for New Zealand
Snow load reduction factor on roofs with slopes less than 10 degrees should be reviewed- Snow Load Allowance AS/NZS 1170.3
Inspection should be required during construction to ensure quality assurance of welds and connections
On site steel fabrication should be supervised and completed by qualified personnel
Minimum levels of professional competency should be defined
Existing roof structures at collapse critical locations should be inspected for adequate connection detailing
Buildings susceptible to snow loading should be designed to resist progressive collapse in case of snow overload
Recommendations for Long Span Trusses exposed to Snow Loading
Unexpected snow events could impose higher loads on the building than the building was originally designed for. Some recommendations to prepare for unusual snow loading conditions as outlined in the Snow load safety guide are listed below (FEMA, 2013).
Long span trusses should have adequate bracing since they have lower structural redundancy than short span roofs
Roof load capacity should be increased if required
Metal plates connecting truss member chords should be inspected
Vertical position of trusses should be checked that they are not leaning out of plane
Faults in building components should be repaired as soon as they are noticed so they do not cause greater damage
Appropriate snow removal strategies should be identified and implemented
Conclusion
Engineers need to exercise an acceptable degree of competence, diligence and care for the health and safety of the public (Ratay 2009 pp 7.6, 7.13). Special care should be taken in the design and construction of long span buildings as their collapse could cause injury to the public or loss of life and property also insurance claims and legal repercussions could be avoided by complying with design standards and codes. Site supervision should be conducted regularly to ensure the construction complies with the design requirements. Also warning signs of failure should be heeded to so a structural failure can be prevented. The lessons learned from this failure and recommendations can be applied to existing buildings and new construction as a safeguard against collapse of long span buildings.
This industry article discussed the roof failure, the insurance claim and plans for the rebuild of the structure. They also state the importance of learning from the experience and ensuring new designs meet and exceed the building standards.
The practice advisory provides advice and information for owners, territorial authorities and structural engineers. It was produced following the technical investigation report of Stadium Southland roof collapse.
This is a detailed report that contains information about the causes of collapse, including loading requirements and design changes, construction defects, inadequate site supervision and design and detailing defects.
It provides information on measures that can be taken to reduce the potential of snow load induced structural failures and it provides guidance on identifying roofing systems that may be vulnerable to collapse and monitor buildings for signs of potential failure.
Details the decision of the disciplinary committee in relation to investigation of the collapse of Southland Stadium. The disciplinary hearing of the consulting engineer responsible for the design of the building with the Institution of Professional Engineers New Zealand (IPENZ). It highlights some of the errors made on the job and the decision to dismiss him from the institution.
Snow storm data was collected to determine the amount of snow loading on the roof. It presents information on the quantity and duration of the snowfall reports and the observed ground snow loading then compares them to those in the building standards for designs completed when the stadium was built.
This failures wiki installment discusses the collapse of the Hartford Civic Center Coliseum. The similarities of this collapse with the Stadium Southland collapse were mentioned.
Kliment, Stephen A. (1981). “Towards Safer Long-Span Buildings.”The American Institute of Architects.
This book presents a review of the convention of professional panel of architects, engineers and contractors, set up by the American Institute of Architects to discuss the collapse of long-span buildings.
This news report stated that snow loading was insufficient to cause the collapse of Stadium Southland’s roof. They highlighted the level of non-compliance uncovered from the investigation findings.
This article is part of a series providing examples of the changes that have been made in structural design and construction from past structural failures. Part 2 focuses on the changes made from building failures.
Ratay, Robert T. (November 16, 2009). “Forensic Structural Engineering Handbook.” Second Edition. McGraw-Hill Professional.
This book covers a various topics related to building failures causes of failure, engineering response to failure, and failure-damage modes in steel structures. It also talks about the legal concern after a failure and how the legal aspects may be handled.
Report prepared by consulting engineers providing a detailed analysis following the investigation of the Stadium Southland roof collapse. It provides several images, illustrations and calculations related to the failure. It also discusses the collapse sequence, causes of the roof collapse and provides some recommendations for future designs.
Invercargill, New Zealand - September 18, 2010
Yewande Abraham, PhD Candidate, Pennsylvania State University, 2014
Table of Contents
Introduction
The Stadium Southland roof collapsed around noon on September 18, 2010. Construction of the stadium commenced in 1999 and was completed in 2000. The stadium, shown on the left side in Figure 1, served as an indoor sports facility and contained multipurpose community courts, event courts, a climbing wall and other state-of-the-art facilities for the Southland region. Invercargill, NZ suffered a heavy snowstorm of a 1 in 250 year snow design level that was suspected as causing unusually high loads on the steel tube truss roof. There was no injury or loss of life resulting from the collapse. The roof collapse was thought to have been caused by the heavy snowfall that took place (Otago Daily Times Staff, 2010). After thorough investigation, it was concluded that the roof collapsed due to a combination of factors in addition to the snow loading from the heavy snowfall (Smith and Hyland, 2012). Some of the other factors that contributed to the collapse are design changes, defects in construction, and poor workmanship.
Following the collapse, the roof was redesigned incorporating better safety features and increased load capacity; other affected areas within the facility were also rebuilt. The stadium has been improved to a world-class venue. It reopened May 9, 2014 and was renamed ILT Stadium Southland. It continues to host various events and shows it also provides recreational and sporting facilities to the Southland region.
Key Words
Steel Trusses, Large Span Roof, Snow Loading, and Welds.
Stadium Description
Stadium Southland is located at Invercargill, New Ze
Stadium Southland has a total area of 98038 ft2 (9108 m2) and the roof structure consists of long span hollow steel trusses. The trusses comprised square hollow sections and rectangular hollow sections with long spans of about 120 ft. (36.6 m); the roof comprised 0.02 in (0.55 mm) thick profiled metal sheet cladding, on safety netting and building paper (Smith and Hyland 2012, pp 22). The trusses supported the proprietary cold formed steel purlins with two lines of purlin braces in each bay. The purlins above the community courts spanned east to west and north to south above the event courts. Figure 2, created by Smith and Hyland (2012), shows a 3D model representation of the structural frame of the roof with the trusses above the community courts ( towards the south) and the events courts (towards the north). Some of the trusses were supported on concrete columns and others had part height concrete wall panels with steel framing.
Events Leading up to the Collapse
While the building was under construction, excessive deflections were detected in the steel roof trusses above the community courts. The trusses were noticeably sagging and the problem had to be corrected (Southland Times, 2012). Remedial work was carried out while the structure was still under construction in year 2000 to address the structural issues with the roof trusses and the connections including some measures which were taken to correct the deflections. The deflections were caused by design changes that were made during construction to reduce the steel quantities in some of the steel trusses of the community courts.
Specifically, changes were made to the design capacity of the community court trusses, the connections to the south wall columns, the connections of the spine trusses to their supporting columns and cracking in the spine steel truss (Smith and Hyland 2012, pp 15). Even though these deflections were addressed, there were questions of whether remedial works were undertaken correctly and if the design elements met the loading requirements of the New Zealand building codes. Also in 2006, there was movement in the roof line of the stadium where the trusses spanned the community courts (Baker, 2010). The roof structure was reviewed by the secondary consulting engineer who said the trusses were adequate enough to support the loads (Heaney & McElroys, 2014). Nothing was done at that time to correct this concern since the roof was deemed safe. The roof held up till four years later when it collapsed under heavy snow.
The severe snow storm that took place in Invercargill NZ caused damage to some other buildings in the Invercargill area. Most of the snowfall was thought to have taken place from 8pm Sept 17, 2010 to noon Sept 18, 2010. The National Institute of Water and Atmospheric research (NIWA) reported the average ground snow was 0.45 kPa (9.4 lb/ft2) and roof snow load at the time of the collapse was estimated to be 0.30 kPa (6.27 lb/ft2). The allowable roof snow load for the design was 0.47 kPa (9.82 lb/ft2) (Hendrikx 2010, pp 10).
Investigation into Causes of the Collapse
Before the investigation was conducted for the Department of Building and Housing (DBH) to determine the causes of the collapse of Stadium Southland, the structural evaluation of the structure was carried out so the cause of the collapse can be determined through structural analysis using the applicable design standards in New Zealand for the time the structure was designed. The investigation uncovered several problems with the design and construction of the stadium (Smith and Hyland, 2012). The full investigation report can be found here.
The results of the technical investigation showed that in addition to the heavy snow fall, a number of other factors contributed to the collapse of the stadium as listed below.
- Heavy snowfall
Although it was an unusual snow event, the National Institute of Water and Atmospheric research (NIWA) reported that the average ground snow and roof snow load did not exceed the allowable design snow load (Hendrikx, 2010). From the analysis of the snow loading it can be inferred that the heavy snow could not have been solely responsible for the failure.- Construction Defects
Some aspects of the steel fabrication were not compliant with the drawings. There were defects in connection of elements, welding and installation of strengthening and end bearing plates. Some of the connections to the concrete wall were brittle with missing connection bolts. Some of the steel truss members had less thickness than was required to reduce cost.- Design and Detailing issues
There were problems with the steel shear reinforcement in some of the columns supporting the main roof spine trusses and splices were located at highly loaded areas of the steel trusses above the community courts. There were some design modifications made that were too late to be implemented during construction.- Problems with Remedial Works
There were errors in calculating the loading used for the changes made related to remedial works and design changes were implemented late into the construction. Although the design changes for the remedial works was peer reviewed by a secondary consulting engineer there were still a lot of problems with the design, the same consulting engineer also cleared the roof as being safe when the sagging trusses above the community courts were noticed in 2006 (Heany et al. 2014).- Site Supervision
Some of the design and construction errors would have not been missed if site supervision was thorough (Bach 2012). There were also cases of non-compliance where on site steel fabrication and welding for remedial works were not compliant with design drawings (DBH, 2012a, pp 8), the spacing of reinforcing ties with columns was also less than required by standards.The police was invited to investigate the collapse following the release of the investigation report due to the level of non compliance of the construction (HERA, 2014). The consulting engineer for the project had to take responsibility for his negligence and was expelled from the institution of Professional Engineers New Zealand (IPENZ) for breaching the code of ethics and for his failure to carry out his professional engineering obligations (Hasell et al. 2014, pp 15). The engineer's action was a risk to the public and it was rather fortunate that there was no injury or loss of life resulting from the collapse. Kliment (1981) highlighted the importance of architect and engineer involvement in the construction process, the errors that were made could have been identified and corrected early on if site supervision and inspections were thorough.
Sequence of Collapse
According to the investigation report prepared for DBH, Stadium Southland collapse started at the mid-span to chord site splice in Truss T1 which caused the roof to be was displaced after similar compression failure occurred in nearby trusses T2-T5 above the community courts. The connected spine trusses were also displaced along with the column supports causing the failure to propagate through the structure and damage most of the roof. The collapse sequence diagram outlining the collapsed members as provided in the DBH report is presented in Figure 3 below (Smith and Hyland, 2012, pp 49-50). The damage at the roof level of the community courts and walls are shown in Figures 4, 5 and 6.
It was reported that when the collapse occurred some tennis players were just leaving the stadium and there was one person in the building. They reported that they heard a loud bang and one of the doors to the community courts burst open, there was also flying debris of a roof panel (Smith and Hyland 2012, pp 33). Luckily when the collapse occurred no one was injured. There was extensive damage to the roof above the community courts and the event courts, portions of the end walls on the eastern and western side of the stadium were damaged and the main roof spine truss and column supporting events courts and community courts failed. The purlins were also damaged as a result of the collapse. ILT Velodrome, which is adjacent to Stadium Southland was unaffected and the structure remained intact after the heavy snow event.
Reconstruction of the Stadium
Stadium Southland was rebuilt and renamed ILT Stadium Southland and opened in May 9, 2014. The building size was only slightly increased to 107639 ft2 (10000 m2) but has larger sitting capacity. The cost of rebuilding the stadium was $43 million NZD, which is significantly higher than the cost of the previous stadium which was $10 million NZD, the new stadium was built by the same contractors that constructed the former stadium (ABL, 2014). The insurance paid about $20 million NZD of the reconstruction cost.Reconstruction started in March 2011 and the building was initially scheduled to be completed in March 2012 but was late by about 2 years and was completed in February 2014. The Christchurch earthquake that occurred in February 2011 was one of the factors that delayed the project. Design changes were made to strengthen the structure and improve the redundancy of the building following the earthquake which also contributed to the increasing cost. The stadium was also upgraded, the construction was worth the wait and ILT stadium is classed as a world-class venue. The lessons learned from the failure were adhered to and a safer and structurally sound building was constructed.
Lessons Learned
The space frame roof of the Hartford Civic Center Coliseum collapsed in 1978, it bears some similarities to the Stadium Southland roof collapse. There were concerns about the excessive deflections that were observed in the steel space roof frame that was not corrected there were also some design and construction errors which contributed to the collapse of the building after five years (Johnson, 2009). The collapse of the Hartford Civic Center Coliseum brought about some changes in the design and construction of long span trusses by introducing peer review of structural design calculations (Ratay 2011, pp 2). Following the collapse of Stadium Southland roof, several recommendations were made to the Department of Building and Housing. Some other recommendations made following investigation of the Christchurch earthquake were mostly implemented to improve the safety and redundancy of structures in New Zealand (DBH 2012b, pp 11-14). Some of the specific changes can be found in the Practice advisory for welding and section checks in long span steel roof trusses. The document provides guidelines for the inspection of roof trusses and weld connections. Some of the changes made in industry following the investigation were incorporated during the reconstruction of the stadium.
General Recommendations
When building failures occur and the failure has been investigated, recommendations are made to prevent reoccurrence, suggest improvements and implement changes that are beneficial to the design, building owners and to the industry. A summary of the recommendations which can be found in the report prepared for the Department of Building and Housing in New Zealand are presented below (DBH 2012a, pp 11-14). Some of these recommendations are also in line with some of the conclusions drawn from AIA in relation to checking design calulations (peer review) and making design decisions on the field (Kliment 1981, 2).
Recommendations for Long Span Trusses exposed to Snow Loading
Unexpected snow events could impose higher loads on the building than the building was originally designed for. Some recommendations to prepare for unusual snow loading conditions as outlined in the Snow load safety guide are listed below (FEMA, 2013).
Conclusion
Engineers need to exercise an acceptable degree of competence, diligence and care for the health and safety of the public (Ratay 2009 pp 7.6, 7.13). Special care should be taken in the design and construction of long span buildings as their collapse could cause injury to the public or loss of life and property also insurance claims and legal repercussions could be avoided by complying with design standards and codes. Site supervision should be conducted regularly to ensure the construction complies with the design requirements. Also warning signs of failure should be heeded to so a structural failure can be prevented. The lessons learned from this failure and recommendations can be applied to existing buildings and new construction as a safeguard against collapse of long span buildings.
Bibliography
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Otago Daily Times Staff. (December 10, 2010). “Workmanship Blamed for Stadium Roof Collapse.” Otago Daily Times.
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