By: Ryan McDonald, PSU CE M. Eng. Student Fall 2013, rjm463@psu.edu

Key Words: Algo Centre Mall, collapse, corrosion, steel frame, connection, roof top parking deck



1.0 Introduction


Algo Centre Mall Collapse
The Algo Centre mall is the retail hub for Elliot Lake, Ontario. The complex was commissioned for construction in 1979 and was completed in 1980. The two story structure had 190,000 square feet of floor space and housed some three dozen commercial units as well as a hotel. A prominent feature of the complex was a roof top parking deck. Through 32 years of the mall's service life, this feature would prove to be a liability for the structure and would claim a hand full of lives when it eventually failed.

Whole Building.jpg
Figure 1: Photo 0004, Date of Photo: 23/06/2012, Photographer: Dale Burns, File Name: NP 12065241_0004_7Y71_9435, "Area of Collapse.", Cutesy of the Elliot Lake Inquiry.


The mall complex filled its role as a center of commerce for the community. The driving economic force in the area was the mineral mining resources. The retail occupants of the mall looked to piggy back on this opportunity and utilized the mall facilities. Starting in the mid 1990’s the mineral resources began to dwindle and the area around Elliot Lake began to lose its revenue potential. Due to this fiscal assessment, many of the businesses left the mall and other non-traditional businesses moved in. The mall began to house libraries and public health offices. In 2005 the mall was purchased by a new corporation looking to provide space for potential retail clients.


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2.0 Background


Regardless of ownership, the structure itself had issues. Throughout the life of the mall there had been reports of water leaking into the occupied units within.
This water presence and damage had been so severe that drip tarps were put up in plain sight of the customers. This infiltration lead to a variety of serviceability problems and, eventually, to many businesses leaving the mall. There had been maintenance reports filed, yet these reports went largely without resolution.

Drip_Tarps.jpg
Figure 2: Photo 2: HBC E000000298, Trip tarps in Zellers store. From Exhibits: March 4th, 2013. Courtesy of the Elliot Lake Inquiry.

Zellers.jpg
Figure 3: Photo 3: HBC E000000308, Zellers store front, water damage. From Exhibits: March 4th, 2013. Courtesy of the Elliot Lake Inquiry.

The original construction of the Algo Centre Mall was of precast concrete slabs forming the roof top parking deck upon a steel frame. There still exists some discrepancies between the concrete manufacturer (Coreslab) and the architect/design team, in regards to whether or not water proofing details are within their responsibilities. Since the Elliot Lake Inquiry has not come to a conclusion as of yet (Dec.16th, 2013), the responsibility of the waterproofing detailing is not yet clear. What ever the case, the roof top parking deck allowed water to penetrate the building.

On 1/30/1981 there was a correspondence (Document Id. # AGC P000008310, Elliot Lake Inquiry, Exhibits, March 12-20, 2013) regarding the integrity of the sealant covering the control joint. The building movement had had apparently stretched the expansion joint material past its elastic range. This correspondence also discussed the repair order and time line. There were other repair orders made (Document Id. # AGC P000006145, Elliot Lake Inquiry, Exhibits, March 12-20, 2013) as early as February 1981 with regard to the Bank of Nova Scotia, the Quinn T-Shirt store, and $4,000 worth of claims from Woolco Department Store.


The leaking events correspond with events of heavy wet snow and rain. On April 13th, 1982 there is a correspondence (Document Id # AGC P000006088, Elliot Lake Inquiry, Exhibits, March 12-20, 2013) that discusses how the evening before 5 inches of wet snow had fallen. At the start of business on the 13th there were several leaks reported in several different locations in the mall. This is yet another example of the roof top parking deck being the source of water infiltration. Though these events were early in the life of the Algo Centre Mall, they represent problems that continued through the life of the building.

3.0 Events Preceding Collapse


While there had been repairs made to the roof top parking deck and canopy, these were best described as "Band-Aid solutions to patch the ensuing leaks" (Friscolanti, M. (2013, May 08). Warning signs. Maclean's, 126, 23). These repairs consisted of removing debris and material from cracks with a chipper or hand grinder. Once complete sealant would be injected into the prepared crack(Document Id # AGC P000006038, Elliot Lake Inquiry, Exhibits, March 12-20, 2012). These types of repairs were the typical solutions to the leaking problem.

Three years before the fatal collapse, a mall employee was given the job of again trying to stop the "incessant leaks" (Friscolanti, M. (2013, Mar 13). Ignored, until it was too late. Maclean's, 126, 18) of the parking deck. Mr. Yakimov had 20 years of construction industry experience. What this man saw can only be described as alarming. He ventured up to the parking deck and witnessed "a flex in the concrete surface" (Friscolanti, M. (2013, Mar 13). Ignored, until it was too late. Maclean's, 126, 18) as a car passed above him. He tried to investigate further but he "couldn't inspect the entire beam because part of it, including its welded connection to a vertical column, was covered in drywall." (Friscolanti, M. (2013, Mar 13). Ignored, until it was too late. Maclean's, 126, 18). After the collapse Mr. Yakimov told investigators that he had instructed the mall's owner to close down the parking deck saying that "some day this was going to end badly" (Friscolanti, M. (2013, Mar 13). Ignored, until it was too late. Maclean's, 126, 18).


Before the collapse, there had been 32 years worth of inspections of the building. Every one of these inspections had missed the indicators for corrosion to the steel frame. The amount of water penetrating to the interior of the building should have alerted the inspectors to a potential problem. The most recent inspection prior to collapse was made just 10 weeks before the event. The inspector had not only made no comment about the condition of the members he had also doctored his report and he labeled the mall "structurally sound". (Friscolanti, M. (2013, May 08). Warning signs. Maclean's, 126, 23)


4.0 Collapse

Security_Photos.jpg
Figure 4. Photo from: **http://www2.macleans.ca/2013/03/07/elliot-lake-inquiry-surveillance-footage-pinpoints-exact-cause-of-mall-collapse/** , From Michael Friscolanti’s article, “Elliot Lake inquiry: Surveillance footage pinpoints exact cause of mall collapse”.

The collapse occurred on June 23, 2012. The failure was due to corrosion of the steel members of the structural frame. The cause of the corrosion was due to the penetration of salt laden water from the winterizing effort of the grounds crew. This solution deteriorated the steel frame so significantly that it failed. The Canadian Institute of Steel Construction Manual would have dictated that all connections in the parking deck would have an infinite fatigue life. This detail would have been nullified by the unanticipated section loss of the members. The water proofing detail as well as the the concrete cover of the steel components should have been adequate as to prevent the water penetration from taking place.

While it took years for this amount of section loss to accumulate, once it did the collapse was primed to occur.
There is video surveillance of the "final straw", a small passenger car traveling over the portion of the parking deck that collapses. It appears to initiate the collapse that begins at the roof top parking deck and proceeds down through the mall levels.











5.0 Cause of Collapse


The chemical process of corrosion has several parts. In this case a metallic surface was exposed to an electrolyte. The deicing salts acted as the electrolytes, and had been dissolved into solution with the presence of water. The solution then migrated through the roof top parking deck and settled on a connection of the frame. After a lengthy exposure time, the chemical process degraded the frame connection and lead to collapse. The water presence below was an indication of the water movement through the structure's skin. In addition to this, the fact that it was coming through the ceiling should have pointed directly to the parking deck as the origin.
Collapse 1 R McD.jpg
Figure 5: Photo 0153, Date: 23/06/2012, Photographer: Dale Burns. Area of the collapse facing south east – middle of the collapse. Volume 3 Appendix N – Photographs. March 12,13,14,19 and 20, 2013. Courtesy of the Elliot Lake Inquiry.
Erroded_connection.jpg
Figure 6: Photo 0216, Date: 23/06/2012, Photographer: Dale Burns. Midrange photograph of the apparent fail point of the beam along the west wall of the collapse. Volume 3 Appendix N – Photographs. March 12,13,14,19 and 20, 2013. Courtesy of the Elliot Lake Inquiry.

Collapse 3 R McD.jpg
Figure 7: Photo 0283, Date: 25/06/2012, Photographer: Dale Burns. Location of the apparent failed beam on the girder – taken from the man basket within the collapse site. Volume 3 Appendix N – Photographs. March 12,13,14,19 and 20, 2013. Courtesy of the Elliot Lake Inquiry.



6.0 What was Learned

After the collapse at the Algo Centre Mall, many governments recognized the susceptibility of their parking infrastructure. The accident sparked the review of inspection depth and intervals as well as maintenance programs. The British Parking Association changed policies from a "self-policing" one to more strict and transparent practices. Passing a law to make inspections an obligation was now described as "vital". In response to the collapse event, 90 parking structure owners were surveyed and it was found that only 40% of them had maintenance programs in place. It also indicated that 26 of those parking structures are in poor condition. (Car parks at risk without legal inspection duty. (2012)) This fact illustrates the susceptibility of these types of structures to corrosion and fatigue problems.


7.0 Similar Parking Deck Collapses

There have been similar failures in multistory parking decks in Nottingham, Ipswich, and Scunthorpe. Over the last 3 years these structures were shut down or demolished after it was recognized that they were in poor condition. (Car parks at risk without legal inspection duty. (2012))


8.0 Conclusion

The Algo Centre Mall collapse is an unfortunate event that was completely avoidable. There exists a responsibility for proper inspection and maintenance techniques and honest reports. Had these efforts been made, this event and others like it would become essentially nonexistent.

9.0 Annotated Bibliography


Friscolanti, M. (2013, May 08). Warning signs. Maclean's, 126, 23. Retrieved from http://search.proquest.com/docview/1349405083?accountid=13158
This magazine article discusses the negligence of the numerous mall owners and building inspectors. There were obvious signs of structural deterioration that lead to complaints from tenants that were flat out ignored.

Dehaas, J. (2013, Sep 18). Caught in the facts. Maclean's, 126, 50. Retrieved from http://search.proquest.com/docview/1433394765?accountid=13158
This magazine article outlines the conclusion of a structural specialist from NORR Ltd. The expert’s conclusion summarizes the causes and ignorance that lead to the collapse of the Algo Mall roof.

Friscolanti, M. (2013, Mar 13). Ignored, until it was too late. Maclean's, 126, 18. Retrieved from http://search.proquest.com/docview/1316155393?accountid=13158
This magazine article details the conversations between investigators and a maintenance man. There were continuous efforts to try to stop leaks in the building. Through these efforts the maintenance man noticed deflections and deterioration of structural members.

Canadian Institute of Steel Construction, Chapter 26 – Fatigue
This handbook discusses the design procedure and life cycles that can be tolerated by a given weld detail.

Friscolanti, M. (2013, Jun 19). One step from death. Maclean's, 126, 57. Retrieved from http://search.proquest.com/docview/1369458508?accountid=13158
This magazine article has security camera photos and diagrams depicting the collapse. Those images coupled with survivor testimony make the article a good source detailing what the moments just prior to and after the collapse of the mall roof were like.

Journal of Failure Analysis and Prevention, © ASM International 2012, 10.1007/s11668-012-9617-6
This journal article quotes a Canadian Professor of Materials Science Engineering as saying the structure was “too unstable to investigate” after the collapse.

PEO launches investigations of algo centre mall collapse in elliot lake. (2013). Building, 62(6), 8. Retrieved from http://search.proquest.com/docview/1269723013?accountid=13158
This journal article discusses the powers and scope of an investigation by the Professional Engineers of Ontario into the work done by license holders. The work done must be performed up to standards outlined in the Professional Engineers Act.

Car parks at risk without legal inspection duty. (2012). New Civil Engineer, Retrieved from http://search.proquest.com/docview/1023457086?accountid=13158
This trade journal article discusses the ramifications of the collapse of the roof top parking deck within the industry. The collapse had other governments investigating the state of their parking infrastructure.

Elliot Lake inquiry: Surveillance footage pinpoints exact cause of mall collapse
http://www2.macleans.ca/2013/03/07/elliot-lake-inquiry-surveillance-footage-pinpoints-exact-cause-of-mall-collapse/
This article has photos that show progressive shots of the collapse.

Deicing Salt - Recognizing the Corrosion Threat
http://www.imoa.info/download_files/stainless-steel/DeicingSalt.pdf
This article describes the corrosion process as it pertains to metal surfaces and electrolytes.

Elliot Lake Inquiry
http://www.elliotlakeinquiry.ca/exhibits/index.html
This Inquiry has a wide variety of submissions, witness statements, graphics, and exhibits presented to the Government of Ontario regarding the failure event.