Church College Of New Zealand July 2009 Engineering Report

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CHURCH COLLEGE OF NEW ZEALAND – IS IT SUSTAINABLE? By EL Bydder (PhD, MSc, CEng, FNZIP, MIEE, Chartered Engineer) July 1, 2009 I have studied detail design drawings of buildings and site plans for the Church College campus on file at Hamilton City Council. I have also carried out a close inspection of the David O McKay building in an effort to determine whether it is sustainable, particularly with respect to earthquake risk and modern earthquake standards. It may be noted that 43 detailed drawings of the McKay building are labelled both in the council records and on the drawings as “The Mathew Cowley Memorial Building.” Clearly at some later stage building names were changed and the present Mathew Cowley building is a different building on the same campus. The drawings were filed with the then Waipa County Council in 1956 as part of the building, inspection and consent procedures. Additions were made in the 1970s to add a Student Centre, however a study of those additions is not dealt with in this report. The Church College campus consists of approximately 60 buildings, varying from huts and sheds to the David O McKay building, which as the main school building is the crown of the college. The jewel in this crown is undoubtedly the remarkable full-size indoor gymnasium/basketball court and auditorium complex. These spaces can be combined by moving huge folding doors to give an unfettered open floor space of about 18,000 square feet (1900 m2). July 1, 2009 – Second Report on Church College of New Zealand – EL Bydder – Page 1

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Transcript of Church College Of New Zealand July 2009 Engineering Report

Page 1: Church College Of New Zealand July 2009  Engineering Report

CHURCH COLLEGE OF NEW ZEALAND – IS IT SUSTAINABLE?

By EL Bydder (PhD, MSc, CEng, FNZIP, MIEE, Chartered Engineer)

July 1, 2009

I have studied detail design drawings of buildings and site plans for the Church College campus on file at Hamilton City Council. I have also carried out a close inspection of the David O McKay building in an effort to determine whether it is sustainable, particularly with respect to earthquake risk and modern earthquake standards.

It may be noted that 43 detailed drawings of the McKay building are labelled both in the council records and on the drawings as “The Mathew Cowley Memorial Building.” Clearly at some later stage building names were changed and the present Mathew Cowley building is a different building on the same campus.

The drawings were filed with the then Waipa County Council in 1956 as part of the building, inspection and consent procedures.

Additions were made in the 1970s to add a Student Centre, however a study of those additions is not dealt with in this report.

The Church College campus consists of approximately 60 buildings, varying from huts and sheds to the David O McKay building, which as the main school building is the crown of the college. The jewel in this crown is undoubtedly the remarkable full-size indoor gymnasium/basketball court and auditorium complex. These spaces can be combined by moving huge folding doors to give an unfettered open floor space of about 18,000 square feet (1900 m2).

I have considered a report entitled: “Temple View Church Facilities Executive Report – Church College of New Zealand, Hamilton New Zealand Temple, Fosters Rd Meeting House” by Beca Carter Hollings and Ferner Ltd.

According to a covering letter to the report, issued by the Church of Jesus Christ of Latter-Day Saints out of a Carlington, New South Wales, Australia office, the Beca report appears to have been used to cast doubts on the sustainability of the college facilities.

July 1, 2009 – Second Report on Church College of New Zealand – EL Bydder – Page 1

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Although the Beca report is short on technical details, I wish to comment on the most significant section, “1. Design & Construction”, which implicitly provides an evaluation of the college facilities. The Design and Construction section of the Beca report does not single out any particular building for comment, even though the college buildings range from small single story shelters to the major multi-storey McKay building with its basketball court, auditorium, gymnasiums, indoor swimming pool, cafeteria, classrooms, offices and other facilities.

This section of the Beca report states “Generally, however, most load bearing walls are of masonry construction with occasional light reinforcement. Non load-bearing walls and shorter load-bearing walls are typically un-reinforced". As noted earlier, there are about 60 buildings shown in the college Site Location Plan dated 1956, ranging from sheds and huts to the McKay building. Nearly all of these are concrete masonry. It is no doubt correct that at least some of these will have “load bearing walls … of masonry construction with occasional light reinforcement” and that “some walls are typically un-reinforced” but this is certainly not the case for the McKay building.

To say the obvious, these comments in the Beca report are of little relevance because it is not specified what the design and/or construction status of any particular building is or was. There is no significant danger in having the masonry walls of a small storage shed un-reinforced (if that is the case), but obviously this would be intolerable if it were to apply to the McKay building.

The Beca report then asserts that “due to the state of engineering knowledge in the 1950s the designs essentially considered gravity vertical loads and wind lateral loads only. Consideration was not given to lateral loads arising from earthquakes.” With respect to the McKay building, this is certainly not the case. The detailed design of this building is highly conservative, with heavily over-designed trusses and massive steel bracing in all dimensions in the roof structure (drawings 14, 24 and 27). Design load bearing is by way of reinforced concrete columns and beams to which the trusses are strongly connected (drawings 2, 12, 13, 39). In addition, the spaces between the columns which support these concrete beams are filled with well-reinforced concrete masonry structures which are integral with the truss supporting beams (drawing 29). There is extensive cross bracing of the roof structure by way of 7/8” steel rods with turnbuckles (drawing 26). This results in a very solid and massively braced structure. The trusses are so deep and so well connected to the wall structure that they can be considered as cantilevered.

July 1, 2009 – Second Report on Church College of New Zealand – EL Bydder – Page 2

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The tops of the trusses are solidly attached to the steel reinforced concrete beams and columns typically by way of 4 x ¾” x15” steel bolts set in the tops of the beams, while the bottoms of the trusses are welded to brackets solidly anchored in the reinforced concrete columns (drawing 27).

This structure results in immensely strong lateral bracing and anchoring which in my view is at least equal to that required for current NZ building code requirements. Similarly, the roof structure strength and bracing is of a very high standard which would fully meet the current building standards. With their infill of reinforced concrete masonry with its integral beams, the wall structures are both capable of bearing a high load and providing high strength lateral bracing.

The Beca report then suggests that as “the buildings were constructed in the late 1950s by church missionary volunteer labour aided by skilled supervision” there are “a number of instances where there is significant variation in quality between the design details on the drawing and the actual as-built construction”. I have carefully and thoroughly inspected the McKay building and compared all the accessible critical areas such as bracing, connections, welds and the like with the drawings and can find no discrepancies with regard to the drawings.

I also note that concrete compaction of the reinforced columns and beams appears to be consistent, based on my visual inspection of the unpainted areas that can be seen in the roof cavities.

In conclusion, I am confident that the structural design of the McKay building was thorough, conservative, intelligent and demonstrated familiarity with and use of bracing and connection qualities that were not in the NZ building codes at the time. At least a quarter of a century before this building was designed in the United States, that country was very familiar with the design and building of massive concrete reinforced skyscrapers. It was also familiar with the problem of designing in earthquake prone cities. On the other hand, some multi-storey buildings of a similar age in the Hamilton CBD were built with un-reinforced clay brick infills.

In any event, the engineering design of the McKay building is of a very high quality and in my view would fully meet the current requirements of the building code. Furthermore I would suggest that, far from being an adversity, the use of dedicated volunteer labour under skilled supervision results in a collective determination to maintain the highest possible standards, to ensure the fullest integrity of the building and to produce a result that everyone involved is intrinsically proud of.

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My conclusion is that the David O McKay building is fully sustainable both in its use of permanent materials and with respect to modern earthquake design standards.

Personal Observation

I must congratulate the designers of this building and the personnel involved in its construction. They have clearly done a magnificent job and it appears that there was an expectation that the building would become an iconic structure on the landscape of New Zealand.

July 1, 2009 – Second Report on Church College of New Zealand – EL Bydder – Page 4