Ministry of Education Canterbury Earthquakes€¦ · Christchurch earthquakes (September 2010, February 2011 and June 2011) on the Ministry’s school buildings and infrastructure

Ministry of Education

Canterbury Earthquakes

Impact on the Ministry of Education’s School Buildings

Ministry of Education

Canterbury

Earthquakes

Impact on the Ministry of Education’s

School Buildings

© Opus International Consultants Ltd 2015

Prepared By Opus International Consultants Ltd

Toby Tscherry Christchurch Office

Structural Engineer 20 Moorhouse Avenue

PO Box 1482, Christchurch Mail Centre,

Christchurch 8140

New Zealand

Reviewed By Telephone: +64 3 363 5400

Will Parker Facsimile: +64 3 365 7858

Technical Principal – Earthquake Engineering &

Building Structures Date: 16 January 2015

Reference: 5-C2102.00

Status: Issue 10 FINAL

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings i

5-C2102.00 | January 2015 Opus International Consultants Ltd

Opus International Consultants Ltd

Executive Summary

This report has been written for the Ministry of Education (“the Ministry” or MoE). The purpose of

this report is to review performance of school buildings in the Canterbury earthquake sequence.

The intent is to assist the Ministry of Education in improving the resilience of their current and

future school buildings in Christchurch and throughout New Zealand.

The post-earthquake review sampled 70 school buildings in Canterbury classified into 25 types.

The majority of school buildings reviewed are single storey, with the remainder being a maximum

of 2 storeys.

Buildings selected range in age from the 1930s through to 1990s. The buildings have been chosen

to be representative of school blocks throughout New Zealand, thus the majority of the sample

captures buildings from the 1950s through to the 1970s, when ‘standard’ designs were used

nationally (or regionally). After this period, one-off designs prepared by local architects seem to

dominate the building stock. It was not attempted to capture these newer designs in the sample,

because the lessons from these one-off designs have less relevance to the national portfolio.

Conclusions drawn about safety emphasize that there were no fatalities on school sites although

some injuries occurred, mostly resulting during egress. The Ministry’s earthquake strengthening

programme has been effective; it prevented building collapse, provided a safe environment for

teachers and students and limited damage to buildings that would otherwise have been more

severely affected. A significant conclusion is that a large proportion of damage was the result of

ground deformation. A key recommendation is that the Ministry consider this and other site

related risks nationally.

Conclusions on structural performance are:

Lightweight wall and roof timber buildings have performed very well generally and in excess of

their calculated capacity.

Seismic retrofit work undertaken has been effective.

A large proportion of building damage was due to ground deformation.

Lightweight buildings with suspended timber floors on shallow footings generally

accommodate ground deformation well and can often be quickly and cost effectively re-levelled.

Overhead heavy building services or items unsecured on shelves can be a falling hazard.

Most heavy roofs have been removed and replaced with lightweight material, which has

reduced the seismic load and damage.

Where blocks have been joined together and the alignment of the principle axes are no longer

maintained such that the footprint is not symmetrical, i.e. joined together to form a T shaped

footprint, increased damage was observed.

Heavy veneer cladding increases damage to internal linings.

Overhead heavy veneer can be a falling hazard if not well tied to timber framing, particularly

above doors and windows.

The open plan blocks have minimal bracing which increases frame distortion and damage.

Some CEBUS type buildings have external nail plates that have failed during shaking without

resulting in collapse. These can be simply retrofitted.

One of the Pre-1930’s Two Storey Block’s has Potential Critical Structural Weaknesses while up

to 11 others have structural weaknesses.

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings ii



Site Considerations – Recommendations Buildings and Infrastructure

An egress and evacuation plan should be put in place for each school site. The main issues are

concerning stuck doors due to differential settlement and potential fall hazards. The assembly

point should also be considered.

Overhead falling hazards relating to poorly tied brick veneer, heavy building services or items

on shelving should be assessed, and if required secured or removed to a lower height.

Consideration should be given to assessing and, if required, strengthening, or removing the

veneer at height to mitigate this risk in a future significant earthquake event. Lowering the

veneer will have the added benefit of reducing the seismic load on the buildings’ structure and

improving its overall performance.

Consideration should be given to upgrading site infrastructure during significant

developments. This would reduce the extent of aged, frequently extended, brittle pipe networks

present on many school sites.

Consideration should be given to the assessment of schools’ existing infrastructure networks,

for their condition and capacity i.e. compliance and vulnerability. This would indicate a need

for the upgrade of any existing infrastructure with newer, more robust systems. This also

reduces the risk of major costs associated with repairing older systems, when repairs carried

out in the future might trigger the requirement for a Building Consent. Discussion with

Councils should also be considered to seek clarity on compliance requirements.

Consideration should be given to contingency measures for lifeline services (water supply &

sewer).

Consider options for hardstands that include ‘full design life’ to mitigate known geotechnical

risks.

Process – Recommendations and further review

Issue minimum standard brief and guidelines for engineering assessment and design which

embodies current ‘best practice’. (We note that the Ministry have subsequently issued

guidelines on importance level for retrofit and new design).

Consider adopting damage resistant designs in high seismicity areas. This could also reduce

the cost to repair non-structural damage, which is estimated to be approximately 70% of the

total repair cost for commercial buildings.

Review processes around construction quality control and construction monitoring by the

designer and Territorial Authorities’ (TA’s) to ensure efficiency and confidence that the design

intent is achieved during construction.

Consider setting up a review panel, perhaps a continuation of the Engineering Strategy Group

(ESG) or similar to USA practice where an independent consultant from an approved panel

reviews design and or construction.

Learnings from other commercial and Ministry of Education buildings should be applied to the

portfolio, for example:

Stairs; review in accordance with Ministry of Business, Innovation and Employment (MBIE)

guidelines.

Precast panels; especially connections and requirements for ductility.

Shear walls; in line with interim design guidelines by Structural Engineering Society New

Zealand (SESOC).

Cross bracing; particularly Reid Brace especially connections and requirements for ductility.

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings iii



Contents

Executive Summary .................................................................................................... i

1 Introduction ....................................................................................................... 1

2 Assessment Scope .............................................................................................. 1 2.1 Limitations ........................................................................................................................ 1 2.2 Infrastructure .................................................................................................................... 2 2.3 Peak Ground Acceleration ................................................................................................ 2 2.4 Geotechnical ...................................................................................................................... 7 2.5 Potential Structural Weaknesses .................................................................................... 12

3 Selection of Buildings ........................................................................................ 12 3.1 Considerations for Selection ........................................................................................... 12 3.2 Selection Criteria ............................................................................................................. 12 3.3 Buildings Selected ........................................................................................................... 12

4 Building Type Structural Review .......................................................................16 4.1 Rating System ................................................................................................................. 16 4.2 Flowcharts and Reference Material ................................................................................ 16

5 Key Findings .................................................................................................... 20 5.1 Summary of Building Results ......................................................................................... 20 5.2 Discussion/Analysis of Results ....................................................................................... 25

6 Conclusions ...................................................................................................... 30 6.1 General Conclusions ....................................................................................................... 30 6.2 Infrastructure Performance/Damage ............................................................................. 31 6.3 Block Specific Conclusions .............................................................................................. 32

7 Recommendations ........................................................................................... 32 7.1 Site Considerations – Buildings and Infrastructure ....................................................... 32 7.2 Process ............................................................................................................................ 33 7.3 Further Review ................................................................................................................ 33

8 Limitations ....................................................................................................... 34 8.1 Other Site Risks ............................................................................................................... 34

Appendix A - School Building Types ......................................................................... A1 A1 Two Storey Classroom Block .......................................................................................... A2 A2 Subfloor Framing ........................................................................................................... A3 A3 Pre 1930s Two Storey Block ........................................................................................... A4

Appendix B – Block Types by School ........................................................................ B1

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings iv



Appendix C – Building Type Performance Summary ................................................ C1

C1 Open Air Veranda block ................................................................................... C2 C1.1 Recommendations & Conclusions ................................................................................. C2

C2 Dominion block ................................................................................................ C3 C2.1 Recommendations & Conclusions ..................................................................................C3

C3 Canterbury block .............................................................................................. C4 C3.1 Recommendations & Conclusions .................................................................................. C5

C4 12 Classrooms double storey Block ................................................................... C6 C4.1 Recommendations & Conclusions ................................................................................. C6

C5 Open Plan Block ............................................................................................... C7 C5.1 Recommendations & Conclusions .................................................................................. C7

C6 CEBUS MK 1 & 2 ............................................................................................... C8 C6.1 Recommendations & Conclusions ................................................................................. C8

C7 CEBUS Modified (1990) .................................................................................... C9 C7.1 Recommendations & Conclusions ................................................................................. C9

C8 Prefabs - Paul Wilkin Design .......................................................................... C10 C8.1 Recommendations & Conclusions ................................................................................ C10

C9 Nayland Block ................................................................................................. C11 C9.1 Recommendations & Conclusions ................................................................................ C11

C10 Hall with Sub-basement ................................................................................. C12 C10.1 Recommendations & Conclusions ................................................................................ C12

C11 Hall without Sub-basement ............................................................................ C13 C11.1 Recommendations & Conclusions ................................................................................ C13

C12 Portacom ........................................................................................................ C14 C12.1 Recommendations & Conclusions ................................................................................ C14

C13 Subfloor Framing ........................................................................................... C15 C13.1 Recommendations & Conclusions ................................................................................ C15

C14 Pre 1930s 2 Storey Block ................................................................................ C16 C14.1 Recommendations & Conclusions ................................................................................ C17

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings v



C15 1940s Single Storey Weatherboard Block ....................................................... C18 C15.1 Recommendations & Conclusions ................................................................................ C18

C16 1950s Double Storey ....................................................................................... C19 C16.1 Recommendations & Conclusions ................................................................................ C19

C17 1960s Nelson Block "Straight" ........................................................................ C20 C17.1 Recommendations & Conclusions ............................................................................... C20

C18 1960s Nelson Block "H Plan" .......................................................................... C21 C18.1 Recommendations & Conclusions ................................................................................ C21

C19 Nelson Single Storey ...................................................................................... C22 C19.1 Recommendations & Conclusions ............................................................................... C22

C20 S68 (school 68-72) .......................................................................................... C23 C20.1 Recommendations & Conclusions ............................................................................... C23

C21 Secondary School Hall ................................................................................... C24 C21.1 Recommendations & Conclusions ............................................................................... C24

Appendix D – Geotechnical Description of School Standard Blocks ......................... D1

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings 1



1 Introduction

Opus International Consultants (Opus) has been commissioned by the Ministry of Education (“the

Ministry”) to review damage to school buildings caused by the recent Canterbury earthquakes.

This report was first issued on 10 February 2012 and has been updated to include:

Refinement to the intensity of shaking zonation to reflect the PGA contours, provided by GNS,

now available on the Canterbury Geotechnical Database1.

Review the Critical Structural Weaknesses (CSWs) in context of the current classification of

structural weaknesses for light-weight timber buildings.

Improve the data on damage for the various blocks based on information available to the

Ministry.

Improve the ground damage classification/zonation to identify the influence that ground

movement had on building damage.

Clarify the standard block types using the Catalogue of Standard Buildings produced by the

Ministry.

Include data from the standard block assessments.

Update the conclusions and recommendations to reflect the amendments to the report.

2 Assessment Scope

This report assesses the structural performance of a series of school building types located at over

40 school sites in Canterbury. The scope of work is to:

Provide a detailed and concise report for use by the Ministry on the impact of the recent

Christchurch earthquakes (September 2010, February 2011 and June 2011) on the Ministry’s

school buildings and infrastructure.

The purpose of this report is to highlight aspects of the buildings and infrastructure that

performed well / poorly to allow the Ministry to improve the resilience of their current and

future school buildings in Christchurch and throughout New Zealand.

2.1 Limitations

The structural assessments conducted by various structural consulting firms were reviewed along

with any information provided by the Ministry and the schools themselves. No additional

structural assessments were performed as per the scope of this project.

The reports reviewed consist of Rapid Assessment forms, which involves a walk around and

through the building (if safe to do so) looking for visible signs of significant structural damage.

This is specified as post-disaster Building Safety Evaluation endorsed by the MBIE (formerly

Department of Building and Housing). Following this, Detailed Engineering Evaluation (DEE)

reports have also been prepared for the Ministry, these generally involve a detailed visual

inspection and calculation of the existing structural capacity of the buildings compared against the

current building code. Where available these have been reviewed to verify the findings discussed in

this report.

1 canterburygeotechnicaldatabase.projectorbit.com




The reports used for this review were completed by a range of consulting firms over an extended

period of time, and this information has been used without review. Opus takes no responsibility

for the reliability of these structural reports, nor the information from these reports that has been

used herein.

The standard building types considered for this study are not exhaustive. If none of the standard

building types match the school of interest, no conclusions should be taken from any similar

building types. The standard building types found in the Canterbury region differ from those found

in other regions. Therefore it is important to use the building type description to get an exact

match. The standard building type names are indicative only, as the same type of buildings may

have different names across the country.

2.2 Infrastructure

This report is focussed on the performance and damage of school buildings, a review of other

Ministry infrastructure is outside the scope of this report. From our involvement in infrastructure

repairs at a number of school sites Opus have formed and provided some conclusions on the

general performance of infrastructure.

2.3 Peak Ground Acceleration

The school buildings have sustained damage in both the 2010 Darfield and 2011 Christchurch

earthquakes. The overall damage resulting from the series of earthquakes is considered in this

report. No distinction is explicitly made between the different events, which may have resulted in

different types of damage. It is not possible to clearly state which events caused specific observed

damage. As an example, the 4 September earthquakes might have caused unobserved damage to

structural elements which failed during the 22 February earthquake.

The ground accelerations were recorded and are shown on Figure 1 and Figure 2, extracted from

the GNS report2. The peak ground acceleration (PGA) in the horizontal direction closely correlates

to the extent of damage caused by the earthquakes.

2 Webb T. H., Beaven J., Brackley H., Gerstenberger M., Kaiser A., McSaveney E., Reyners M., Somer-ville P., Van Dissen R., Wallace L., Bannister S., Berryman K., Fry B., Holden C., McVerry G., Pettinga J., Rhoades D., Stirling M., Villamor P., and Zhao J., ‘The Canterbury Earthquake Sequence and Implications for Seismic Design Levels’, GNS Science Report 2011/128, July 2011.


5-C2102.00 | January 2015 Opus International Consultants Ltd Opus International Consultants Ltd

Figure 1 : Maximum horizontal and vertical PGA’s recorded during the 4 September 2010 earthquake at GeoNet stations

Figure 2 : Maximum horizontal and vertical PGA’s recorded during the 22 February 2011 earthquake at GeoNet stations




Figure 3 and Figure 4 show banded summary contour maps of the ground shaking experienced in

Canterbury as a result of the September 2010 and February 2011 earthquakes overlaid with the

school locations, refer to Figure 7 for a full list of Ministry schools. The PGA contours have been

obtained from the Canterbury Geotechnical Database.

The four different bands are representative of the design level earthquakes where the ‘Return

period’ (R) factor relates to the various expected earthquake intensities for a building with a 50

year design life. The severity rating of each band relates to the annual probability of an earthquake

event, as shown in Table 2-1.

Table 2-1: Return Period Factor Range*

Description Ru or Rs Return Period Factor Range

Return Period Range

Severe R ≥ 1.8 >1/2500

High R = 1.0 to 1.8 1/500 to 1/2500

Moderate R = 0.75 to 1.0 1/250 to 1/500

Low R = 0.35 to 0.75 1/50 to 1/250

*based on new seismicity (Z=0.3)



Z=0.3

Figure 3: Combined Peak Ground Acceleration - Christchurch



Z=0.3

Figure 4: Combined Peak Ground Acceleration - Canterbury




2.4 Geotechnical

Widespread liquefaction occurred during the 22 February event. Figure 5 and Figure 6 show the

foundation technical categories from the MBIE, overlaid with the school locations, refer to Figure 7

for a full list of Ministry schools. These maps provide an indication of the susceptibility to

liquefaction in the city and wider Canterbury.

Comments have been included in Table 5-1 to provide an indication of the extent of damage which

can be attributed to ground movement, and that which has resulted from ground shaking.

Reference can also be made to the maps in Figure 5 and Figure 6 which show the school locations

in relation to the extent of shaking and liquefaction.

2.4.1 Category

The geotechnical classification has been developed by the Ministry and will be available for

Canterbury schools to differentiate the classification from the MBIE Technical Categories for

residential properties (e.g. TC1 – TC3). The report incorporates these classifications where

available, alternatively where these are not available, the MBIE technical categories for the

neighbouring residential properties have been used.

GH1 Geotech Hill Category 1

Future land damage from subsidence or land slip is unlikely and there is no rock fall hazard. Likely

to be able to use standard foundations for buildings of a similar structure and size to those already

present on site.

GH2 Geotechnical Hill Category 2

There is risk from land slips, subsidence and / or a rock fall hazard. Specific engineered foundation

and rockfall mitigation design will be required.

GC1 Geotechnical Category 1

Future land damage from liquefaction or lateral spreading is unlikely. Likely to be able to use

standard foundations for buildings of a similar structure and size to those already present on site.


Minor to moderate land damage from liquefaction or lateral spreading is possible in future

significant earthquakes. The use of standard timber piled foundations for simple single storey

buildings (up to average house size) with lightweight cladding and roofing and suspended timber

floors is likely to be acceptable. The use of enhanced concrete foundations that tie the structure

together for single storey buildings (up to average house size) with concrete slab floors is likely to

be required. Multi-storey and larger buildings may require a site-specific geotechnical

investigation and specific engineered foundation design.





Moderate to significant land damage from liquefaction or lateral spreading (< 500mm) is possible

in future significant earthquakes. Site-specific geotechnical investigation and specific engineered

foundation design is likely to be required.


Significant land damage from lateral spreading (>500mm) is possible in future significant

earthquakes. Site-specific geotechnical investigation and specific engineered foundation design

will be required.

2.4.2 Data Reliability and Confidence

The reliability and confidence of geotechnical information varies depending on the level of

information available at the time of writing the respective school reports. This has been assessed

and commented on in the geotechnical reports when they have been completed by the respective

consultants however it has not been replicated or explicitly stated in this report. Readers are

directed to the source reports for further information of data reliability and confidence.



Figure 5: Technical Categories - Christchurch



Figure 6: Technical Categories - Canterbury




Figure 7: Full List of Ministry Schools




2.5 Potential Structural Weaknesses

A “Critical Structural Weakness” (CSW) refers to a component of a building that could contribute

to increased levels of damage or cause premature collapse of a building.

Apart from one pre 1930s 2 storey block, no blocks were found to have CSWs. Some school

buildings however, do have structural deficiencies or weaknesses that adversely affect the

building’s seismic performance. These weaknesses are not considered to be critical to life safety or

collapse. In these cases the term ‘structural weakness’ has been used.

3 Selection of Buildings

3.1 Considerations for Selection

The aim of the block selection process was to provide a representative of the range of school

buildings typically found throughout New Zealand. Primary, intermediate, and secondary school

building types were considered to account for the differences in building form and scale between

school sectors. Although some of the buildings are suitable for more than one school sector, the

difference in the building footprint between sectors is significant.

Given the relative size of the greater Wellington region and its location in a high seismicity area,

additional effort was made to find block types common in the Wellington region. Notable block

types in Wellington include:

1950s Henderson Blocks: Heretaunga College (none of these have been located for this report).

S68 Blocks (late 60s early 70s): Porirua College, Wainuiomata High.

Nelson Library Blocks: Heretaunga College, Porirua College, Wainuiomata High.

3.2 Selection Criteria

The selection of the school buildings was made based on the following criteria:

Location in the Christchurch area.

Representative of New Zealand school building types.

Range of earthquake damage from minor to significant. and,

Access to existing structural reports and in some cases, structural drawings.

3.3 Buildings Selected

The following buildings have been selected to represent standard types of buildings. The full

description of each building type is presented in Appendix C.




Table 3.1: Standard Block Locations

Standard Type of Building Location

Primary and Intermediate Schools

Open Air Veranda Block

Shirley Intermediate – 60 Shirley Road, Shirley, Chch

Wharenui Primary – 32 Matipo Street, Riccarton, Chch

Wairakei Primary – 250 Wairakei Road, Bryndwr, Chch

Bamford Primary – 6 Gould Crescent, Woolston, Chch

Dominion Block

Hammersley Park Primary – 90 Quinns Road, Shirley, Chch

Banks Avenue Primary – 91 Banks Avenue, Dallington, Chch

Addington Primary – 22 Brougham Street, Addington, Chch

Canterbury Block

Thorrington Primary – 22A Colombo Street, Lower Cashmere,

Chch

Heathcote Valley Primary – 61 Bridle Path Road, Heathcote

Valley, Chch

Hoon Hay Primary – 91 Sparks Road, Hoon Hay, Chch

Freeville Primary – 1 Sandy Avenue, North New Brighton,

Chch


Russley Primary – 75 Cutts Road, Avonhead, Chch

Sumner Primary – 15 Colenso Street, Sumner, Chch

Darfield High – 16 Ross Street, Darfield, Canterbury

Central New Brighton Primary – 140 Seaview Road, New

Brighton, Chch

Twelve Classroom Double

Storey Block

Manning Intermediate – 50 Hoon Hay Road, Hoon Hay, Chch

Branston Intermediate – 35 Amyes Road, Hornby, Chch

Open Plan Blocks

Shirley Primary – 11 Shirley Road, Shirley, Chch

Fendalton Open Air School – 168 Clyde Road, Fendalton,

Chch

Central New Brighton Primary – 140 Seaview Road, New

Brighton, Chch





Heathcote Valley Primary – 61 Bridle Path Road. Heathcote

Valley, Chch

Queenspark Primary – 222 Queenspark Drive, Parklands,

Chch

Bromley Primary – 33 Keighleys Road, Bromley Chch

CEBUS MK I & II



Shirley Primary – 11 Shirley Road, Shirley, Chch

Van Asch Deaf Education Centre (Block K) – 38 Truro Street,

Sumner, Chch

Heathcote Valley Primary – 61 Bridle Path Road, Heathcote

Valley, Chch

CEBUS 4

St Martins Primary – 24 Albert Terrace, St Martins, Chch

Bamford Primary – 6 Gould Crescent, Woolston, Chch

Bromley Primary – 33 Keighleys Road, Bromley Chch

CEBUS Modified (1990)

Fendalton Open Air Primary – 168 Clyde Road, Fendalton,

Chch


Paul Wilkin Design

Sumner Primary – Colenso Street, Sumner, Chch


Nayland

Middleton Grange – 50 Acacia Avenue, Riccarton, Chch

Burnside High – 151 Greers Road, Burnside, Chch

Halls with Sub-basement

under stage

Kaiapoi Borough Primary – 20 Hilton Street, Kaiapoi


Hammersley Park Primary – 90 Quinns Road, Shirley, Chch

Hall without Sub-basement

under stage

Avonhead Primary – 55 Avonhead Road, Avonhead, Chch

Linwood North Primary – 221 Woodham Road, Linwood,

Chch

Portacom Burnside High – 151 Greers Road, Burnside, Chch






Subfloor Framing

St Martins’ Primary – 24 Albert Terrace, St Martins, Chch

Mt Pleasant Primary – 82 Major Hornbrook Road, Chch

Secondary Schools

Pre 1930s 2 Storey Block

Hagley Community College – 510 Hagley Avenue, Addington,

Chch

Avonside Girls’ High – 180 Avonside Drive, Avonside, Chch

Christchurch Boys’ High – Straven Road, Riccarton, Chch

1940’s Single Storey

Weatherboard

Papanui High – 30 Langdons Road, Papanui, Chch

Heaton Intermediate – 125 Heaton Street, Merivale, Chch

Wairakei Primary – 250 Wairakei Street, Bryndwr, Chch

1950s Double Storey

Linwood College – 85 Aldwins Road, Linwood, Chch

Cashmere High – 172 Rose Street, Somerfield, Chch

Avonside Girls’ High – 180 Avonside Drive, Avonside, Chch

Rangiora High – 125 East Belt, Rangiora

Nelson Block "Straight

Block"

Avonside Girls’ High (Gresson Block) – 180 Avonside Drive,

Avonside, Chch

Papanui High (Plimsol Block) – 30 Langdons Road, Papanui,

Chch

Nelson Block "H Plan"

Burnside High – 151 Greers Road, Burnside, Chch

Linwood College – 85 Aldwins Road, Linwood, Chch

Mairehau High – 440 Hills Road, Mairehau, Chch


Nelson Single Storey

Lincoln High – 25 Boundary Road, Lincoln

Mairehau High – 440 Hills Road, Mairehau, Chch

Shirley Boys’ High – 59 North Parade, Shirley, Chch

Kaiapoi High – 101 Ohoka Road, Canterbury





S68 (schools 1968) and MKII

in 1972 Hornby High – 180 Waterloo Road, Hornby, Chch

Secondary school Hall

Lincoln High – 25 Boundary Road, Lincoln

Papanui High – 30 Langdons Road, Papanui, Chch


4 Building Type Structural Review

For this review, school buildings have been identified by their standard type. A “Building

Performance Assessment” has been prepared and undertaken for each building by an Opus

Structural Engineer to assess the damage, consider the repair work undertaken and or required,

identify the structural weaknesses and rate the building.

4.1 Rating System

A rating system has been implemented to simplify the performance evaluation of the buildings and

provide comparison between the different types. The Table 4-1 shows the rating descriptions

which have been used by Opus to rate the performance of each building.

Table 4-1: Summary of Performance/Damage Rating System

Rating Number

Rating Title

Performance/Damage Description

1 Very Well It withstood the earthquake without any significant damage.

2 Well It withstood the earthquake with minor non-structural damage which required minor repairs prior to occupancy.

3 Fair It had extensive non-structural and/or minor structural damage. It needed repairs prior to usage.

4 Poor It had significant structural damage affecting overall structural integrity.

5 Very Poor The building suffered severe structural damage and required urgent strengthening or demolition.

4.2 Flowcharts and Reference Material

All of the information used about the various school buildings and the conclusions drawn after

completion of the Building Performance Assessment forms, are contained in the Appendices A - C.

This material includes:

Flowchart of types: The flowchart is presented in Figures 8 - 11. These have been designed to

help identify the type of building.

School block ordered by type: All block types are listed along with their locations.




School blocks ordered by name: Schools are listed with the types of building that have been

reviewed as part of this work.

Each type of building reviewed has its datasheet containing general photos along with specific

earthquake damage photos. The summary of each building is listed in short form along with

the rating and the earthquake intensity zone.

Figure 8: Single storey relocatable classroom flowchart identification tool




Figure 9: Single storey permanent classroom flowchart identification tool




Figure 10: Double storey classroom flowchart identification tool

Figure 11: Non-classroom building flowchart identification tool




5 Key Findings

5.1 Summary of Building Results

Table 5.1 shows the different building types with their overall rating and comments considering

ground shaking and geotechnical category (refer to Figure 3 to 5).

Table 5-1 - Standard block summary

Building Type School Name Shaking

Intensity

Geotech

Category Rating Comments 3,4

Open Air

Veranda Block

Shirley

Intermediate High TC3 3

Shaking damage primarily due to

ground deformation.

Connection of sub-floor framing to

building assessed to be 11%NBS.

Once strengthened, building is

assessed to be greater than 34%NBS.

Wharenui Primary High TC2 2

Bamford Primary Severe GC2 2*

Wairakei Primary Low TC2 2

Dominion Block

Banks Avenue

Primary High

Blocks 1, 2

and 4- GC4

(>500mm of

lateral spread)

5

Banks Avenue Primary ground

deformation contributed to damage.

Plan irregularity (structural

weakness) due to full length windows

on one side of building; may cause

excessive deformation and potential

falling hazard from the brick veneer.

The assessed capacity is 70%NBS

(NZSEE, Sp = 0.5, Z = 0.3).

Hammersley Park

Primary Moderate TC3 3

Addington

Primary High GC2 2*

Canterbury

Block

Thorrington

Primary High TC2 4

The damage to Thorrington Primary

and Banks Avenue Primary is mostly

due to ground deformation.

The assessed capacity is 41%NBS

(NZSEE, Sp = 0.5, Z = 0.3).

Heathcote Valley

Primary Severe TC2 1

Hoon Hay

Primary High GC2 2

Freeville Primary Low GC3 2

Banks Avenue

Primary High

Blocks 1, 2

and 4- GC4

(>500mm of

lateral spread)

2

Russley Primary Low TC1 2

Darfield Primary High N/A Rural and

Unmapped 3

Sumner Primary Severe TC2 1

Central New

Brighton Primary Moderate TC3 2

* These ratings are based on the DEE summary report as no primary source information about the damage is available.

3 Notes from standard reports and assessments by Opus and others. 4 Establishing the Resilience of Timber Framed School Buildings in New Zealand; 2014 NZSEE Conference





Intensity

Geotech


Twelve

Classrooms

Double Storey

Manning

Intermediate Moderate TC3 2 Lower intensity zone samples.

Limited conclusion but wall

irregularity may be a structural

weakness.

No significant ground deformation. Branston

Intermediate Moderate GC1 3

Open Plan

Blocks

Shirley Primary High TC3 2

Central timber framed shear walls

assessed to be 38%NBS.

No structural weaknesses for the

superstructure.

No significant ground deformation.

Fendalton Open

Air Primary Moderate TC3 2

Central New

Brighton Primary Moderate TC3 1

Bromley Primary Severe GC2 1*

Heathcote Valley

Primary Severe GC1/GH1 3

Queenspark

Primary Low TC2 2

CEBUS 1 Heathcote Valley

Primary Severe GC1/GH1 1*

Resistant to damage due to ground

deformation.


superstructure.

Superstructure assessed to be

49%NBS (NZSEE, Sp = 0.5,

Z = 0.3).

Foundations assessed to be

approximately 40%NBS.


CEBUS 2 (MK I

& II)

Banks Avenue

Primary High

Blocks 1, 2

and 4- GC4

(>500mm of

lateral spread)

1 Resistant to damage due to ground

deformation.

Simple design with a portal frame

bracing system. Monitor condition of

the gangnail plates which provide the

connection at the external frame

connections. These might start to

work loose.


superstructure.



Z = 0.3).



Hoon Hay

Primary High GC2 1*

Heathcote Valley

Primary Severe GC1/GH1 1*

Shirley Primary High TC3 1

Van Asch Deaf

Education Centre Severe GC1 2






Intensity

Geotech


CEBUS

Modified (1990)

Fendalton Open

Air Primary Moderate TC3 1


deformation.

Similar structure to the CEBUS Mk

1&2. Lower intensity zone samples

with no damage.


superstructure.



Z = 0.3).





CEBUS 3 Woolston Primary Severe GC2 1*


deformation.


CEBUS 4

St Martin’s

Primary High GC2/GH1 2*


deformation.


superstructure.



Z = 0.3).




Bamford Primary Severe GC2 1*

Bromley Primary Severe GC2 2*

Paul Wilkin

Design

Banks Avenue

Primary High

Blocks 1, 2

and 4- GC4

(>500mm of

lateral spread)

2 Performed well subjected to ground

movement. Foundations are easily re-

levelled.

Sumner Primary Severe TC2 1

Nayland Middleton Grange Moderate TC1 1 Lower intensity zone samples.

Limited conclusions can be drawn.

No significant ground deformation. Burnside High Low TC1 2

Hall with Sub-

basement

Kaiapoi Borough

Primary Moderate GC3 2 Plan and vertical irregularity. This

may be a structural weakness due to

the tendency of the two sections of

building to respond differently.



Hammersley Park

Primary Moderate TC3 2

Hall without

Sub-basement

Avonhead

Primary Low TC1 2

Roof diaphragm action and wall

bracing provide additional bracing.

Lightweight cladding materials

reduce the seismic demand on the

structure.


Linwood North

Primary High GC2 3

Portacom Burnside High Low TC1 1

Performed well subjected to ground

movement. Hoon Hay

Primary High GC2 2






Intensity

Geotech


Subfloor

Framing

St Martin’s

Primary High GH1 3 The foundation/structure connection

details are critical as they could fail

during large ground deformation or

intense shaking Mt Pleasant

Primary Severe

N/A Port Hills

& Banks

Peninsula

3

Pre 1930’s 2

Storey Block

Hagley

Community

College

High TC2 2

These buildings built in the 1930s are

likely to have CSW, such as

unreinforced brick walls that may

become a falling hazard.

Strengthening works in the 1990’s

carried out to address most

earthquake prone building issues

provides an explanation for their

relatively good performance.

These buildings are heavy and stiff.

Extensive damage at Avonside Girls’

High School due to ground

movement.

Avonside Girls’

High High GC2-3. 5

Christchurch

Boys’ High High TC3 2

1940’s Single

Storey

weatherboard

Papanui High Low GC2 2 This lightweight and low building

performs well under seismic loads.

Ground deformation at Heaton

Normal Intermediate caused

significant damage to foundations

and superstructure cracking.

Heaton Normal

Intermediate Moderate TC3 3

Wairakei Primary Low TC2 1

1950’s Double

Storey

Linwood College High GC3 (CPT

>100mm) 3 Heavy concrete structure susceptible

to ground deformation. This occurred

at Linwood College and Avonside

Girls’ High School.

Insufficient bracing (potential CSW)

in the longitudinal direction due to

the clerestory windows between the

concrete columns; may result in

significant damage to beams and

columns.

Rangiora High Low N/A Rural and

Unmapped 2

Cashmere High High TC3 3

Avonside Girls’

High School High GC2-3 4

1960’s Nelson

Block “Straight”

Avonside Girls’

High High

GC2-3. See

plot provided. 4

Extensive damage at Avonside Girls’

High School due to ground

deformation.

Two storeys of window openings

with masonry veneer beneath the

ground floor windows cause plan

irregularity (structural weaknesses).

Strengthening works in the 1990’s-

2000’s carried out to address most


which explains their relatively good

performance.

Papanui High Low GC2 1






Intensity

Geotech


1960’s Nelson

Block “H Plan”

Burnside High Low TC1 2

Two storey timber framed building in

general “H” formation. Lacks lateral

load resisting elements on the end

walls. Lateral load resisting system

in both directions relies in part on

timber columns cantilevering above

braced walls. These can be

considered as structural weaknesses.

Building assessed to be 36%NBS

with concrete stairs or 38%NBS with

timber stairs (NZSEE, Sp = 0.5,

Z = 0.3). General performance of the

building is likely to be better than the

figures shown above. Higher

capacities may be gained by

estimating the impact of factors such

as load redistribution, secondary

structural elements, energy

dissipation and conservatism in

estimated strength capacities of the

structural elements.

These buildings generally performed

adequately in Christchurch and are

unlikely to collapse during a

moderate earthquake.

Strengthening works in the 1990’s-

2000’s carried out to address most


which explains their relatively good

performance.

The majority of damage at Cashmere

High School is due to ground

deformation.

Linwood College High GC3 1

Mairehau High Moderate TC2 1


1960-70’s Single

Storey

Weatherboard

Lincoln High High TC1 1

At Shirley Boys’ High School, most

of the damage recorded was due to

ground deformation. The lack of

bracing between the windows is a

structural weaknesses.

Mairehau High Moderate TC2 1

Shirley Boys’

High High TC3 3

S68 (School 68-

72)

Kaiapoi High Moderate GC2 2*

Lateral load resistance in both

directions provided by reinforced

block walls and built in reinforced

block piers.

Some loads at roof level transferred

to block walls through light,

primarily gravity, steel frames. This

may be considered a structural

weakness, but is unlikely to lead to

collapse during a moderate

earthquake.

The damage at Kaiapoi High School

is mostly due to ground deformation.

Hornby High Low TC1 1





Intensity

Geotech



Secondary

School Hall

Lincoln High High TC1 1

Low and moderate intensity zone

samples and no damage.


Papanui High Low GC2 1


Aranui Block Woolston Primary Severe GC2 1*S


5.2 Discussion/Analysis of Results

Table 5-2 provides a brief overview of building performance by type, relating the level of shaking

with the level of performance in broad qualitative terms.

Buildings that have experienced high or severe shaking but have low damage are identified as high

performers in the upper left (green shaded) cells. In contrast, those buildings that have significant

damage whilst only experiencing low or moderate shaking are identified as poor performers and

are shown in the lower right (red shaded) cells.

These results should be read with due consideration for the many factors that affect the behaviour

of a structure, including:

The intensity zone in which the building was located. The “Low” zone buildings should be

considered as not seismically tested. When looking at results for the “Moderate” and “Severe”

zones, the buildings have been considered to have been tested by seismic activity.

The type of shaking or the ground deformation effect differs from site to site.

Blocks which have been identified as a certain building type and built in a specific era may have

been modified more recently. This has generally not been taken into account for this review.

Note that the red text in italics indicates that this block has a geotechnical category of 3-5 (1 being

“good” ground, 5 being red zone).




Table 5-2: Performance Summary

Performance/Damage Rating

1

Very Well

2

Well

3

Fair

4

Poor

5

Very Poor

Shaking Intensity

Severe Canterbury (2)

Open Plan

CEBUS 1

CEBUS 2

CEBUS 3

Paul Wilkin

Aranui

Open Air Veranda

CEBUS 2

CEBUS 4

Subfloor Framing (unmapped)

Open Plan

High CEBUS 2

CEBUS 2

Single Storey WB

Secondary Hall

Secondary Hall

Nelson H

Open Air Veranda

Canterbury & Canterbury

Paul Wilkin

Open Plan

CEBUS 4

Portacom

Pre-1930 2 Storey

Pre-1930 2 Storey

Open Air Veranda

Canterbury (unmapped)

Dominion

Single Storey WB

1950s 2 storey (2)

Nelson H

Subfloor Framing

Hall without SB

Canterbury

1950s 2 storey

Nelson Straight

Dominion

Pre-1930 2 storey

Moderate Open Plan

CEBUS M

Nelson H

Nayland

Single Storey WB

Canterbury

Open Plan

12 Classrooms 2 storey

Hall SB (2)

S68

Single storey WB

Dominion

12 Classrooms 2 storey

Low CEBUS M

Single Storey WB

Secondary Hall

Portacom

Nelson Straight

S68

Open Air Veranda

Nayland

Canterbury

Hall SB & Hall without SB

1950s 2 storey (unmapped)

Nelson H

Open Plan

Single Storey WB

Note that the Italics and red text indicate this block has a geotechnical category of 3-5 (1 being “good” ground, 5 being red zone)




5.2.1 Earthquake Damage

When liquefaction and ground deformation have been observed, a large proportion of the building

damage is likely to be attributable to ground deformation. Consequently, a site geotechnical

assessment should be performed in addition to building type assessment to show which blocks are

more vulnerable to shaking and ground deformation.

5.2.2 Building Type Modifications

Different types of modifications such as retrofitting and strengthening of buildings may have been

undertaken. For example, the MoE directed that heavy roof tiles be removed following a report

completed by Connell Wagner Limited5; a lightweight roof improves seismic performance.

5.2.3 Construction Issues

Some construction problems were noted during the overall assessment process. For example, the

lack of sufficient connections from the brick veneer to the timber walls which can be a hidden

structural weakness. Variable mortar quality also affects the performance of brick veneer.

Investigation findings into the performance of veneer ties has been undertaken by Opus (refer to

Opus methodology report for MoE). Investigation into non-structural veneers in Canterbury and

around New Zealand continues and information currently available has found that the effectiveness

of installed ties is highly variable. An early recommendation from this work is to carry out a veneer

tie investigation in areas of high seismicity, where veneer could be a potential fall hazard. If ties

are adequate, the veneer performance is likely to be good.

5.2.4 Analysis of Results

Table 5-2 illustrates how the different block types have performed under varying shaking

intensities and geotechnical conditions. The following describes performance trends observed.

5.2.4.1 Data Scatter

There are a number of blocks of the same type which have a different rating, for example the

Canterbury block for high shaking intensity is rated 2, 3, and 4 (well, fair and poor) at different

sites. This sort of scatter is normal in earthquake damage data, and is due to a number of factors

including:

Variation in shaking due to local soil effects;

Different block orientation;

Different block construction details, due to age and architectural finishes; and,

The limitations and simplifications made in the assessment.

5 Connell Wagner Limited, ‘Technical Guidelines for Structural Mitigation Work’, www.minedu.govt.nz, July 2003 – revision 7




5.2.4.2 Best Performing Blocks

All of the timber framed standard school block designs performed well. The most common blocks

in the review; Canterbury, Open Plan, and CEBUS all performed “very well” or “well”, even in high

or severe shaking intensity areas.

Generally, the high performers were blocks which had tolerated ground deformation with minimal

damage. The reasons for the lightweight and ‘prefab’ type blocks performing well are:

The re-locatable classrooms are designed to be lightweight so they can be easily lifted;

Lightweight cladding means less seismic mass and therefore lower demand on the structure;

and,

The foundations are typically timber piles with timber subfloor frames which can accommodate

differential movement without significant structural damage, although linings may be affected.

The high performing blocks with low damage (rating 1 and 2) with high or severe shaking and high

geotechnical category were:

CEBUS 2;

Hall;

Paul Wilkin;

Canterbury Block;

Pre 1930s 2 storey; and,

Nelson H.

With the exception of the pre 1930s 2 storey block and Nelson H block, all of these buildings are

single storey comprising a lightweight timber frame. The pre 1930’s 2 storey blocks are essentially

unreinforced masonry (URM) structures and would typically be expected to have a poor

earthquake response. However, at Christchurch Boys High School, extensive structural

strengthening works were completed in the 1990s which significantly reduced damage.

Blocks with low damage (rating 1 and 2) with high or severe shaking intensity and a low

geotechnical category (GC1-2 “good” ground) were:

Canterbury Block;

Paul Wilkin;

Single Storey Weatherboard;

Hall;

CEBUS 2;

Open Air Veranda;

Open Plan; and,

Portacom.

All of these buildings are lightweight timber framed structures, generally having lightweight roof

cladding. These buildings have been shown to perform very well in earthquakes due to the high

ductility, flexibility and strength of light timber frame construction.




5.2.4.3 Blocks with Significant Damage

Blocks with significant damage (rating 3 and 4) with high shaking and high geotechnical category

(GC3-5) were:

Open Air Veranda;

Dominion;

Single Storey WB;

1950s 2 storey;

Nelson Straight; and,

Nelson H.

With the exception of the 1950s 2 storey blocks, the high damage rating is due to substantial land

deformation rather than structural damage due to shaking. These structures are of lightweight

timber framed construction and although the Nelson blocks can have structural weaknesses, these

were remediated with structural strengthening in the 1990s.

The 1950s 2 storey blocks are heavy reinforced concrete structures, potentially having insufficient

longitudinal bracing due to clerestory windows. Two of these blocks were also subjected to land

deformation, further increasing the observed damage.

Blocks with severe damage (rating 5) with high shaking, coupled with both differential settlement

and ground deformation were:

Dominion Block; and,

Pre-1930s 2 storey;

The Dominion Block was located at Banks Avenue Primary. This site has a geotechnical category of

GC4, with significant lateral spread expected. Although the building comprises a relatively

lightweight timber frame with brick veneer, more damage was observed compared with other

blocks of this type due to significant land deformation.

The Pre-1930s 2 storey block which performed poorly was located at Avonside Girls High. This site

suffered extensive land deformation. Despite the strengthening in the 1990s, the ground

deformation caused significant damage to this heavy brittle building.




6 Conclusions

Due to the qualitative nature of this review, the conclusions have been separated into three

categories;

6.1 General Conclusions

6.1.1 Building Types

70 school buildings classified into 25 types have been reviewed.

The majority of school buildings reviewed are single storey. The remainder are a maximum of

2 storeys.

6.1.2 Safety/Occupancy

There were no fatalities on school sites during the Canterbury earthquake sequence.

Some injuries occurred, mostly resulting during egress.

Potential / critical structural weaknesses did not result in collapse of any school buildings but

did result in additional damage.

The Ministry’s earthquake strengthening programme has been effective, as it prevented

building collapse, provided a safe environment for teachers and students, and limited damage

to buildings that would otherwise have been more severely affected.

We understand that prior to the earthquakes, a programme of replacing glass with safety glass

in windows and doors along exit routes had been implemented. This appears to have been

effective as there has been very few reported instances of broken glass.

6.1.3 Building Performance/Damage

Lightweight timber framed buildings have performed very well and generally in excess of their

calculated capacity.

Seismic retrofit work undertaken has been effective.

A large proportion of building damage was due to ground deformation.

Lightweight buildings with suspended timber floors on shallow footings generally

accommodate ground deformation well and can often be quickly and cost effectively re-levelled.

Overhead heavy building services or items unsecured on shelves can be a falling hazard.

Most heavy roofs have been removed and replaced with lightweight material, this has reduced

the seismic load and subsequent observed damage.

Where blocks have been joined together and the alignment of the principle axes are no longer

maintained such that the footprint is not symmetrical, i.e. joined together to form a T shaped

footprint, increased damage was observed.

Heavy veneer cladding increases damage to internal linings.

Overhead heavy veneer can be a falling hazard if not well tied to timber framing, particularly

above doors and windows.




6.1.4 Process

There is inconsistency around the naming of school buildings.

There is no reliable database of drawing information for the building portfolio.

The post-earthquake inspection regime adopted by MoE has been effective.

Retrofit and assessment of buildings in some cases has not adequately addressed global site

issues, such as liquefaction related lateral spread at Jobberns/Gresson Blocks at Avonside Girls

High.

6.2 Infrastructure Performance/Damage

6.2.1 Water

School water supply systems generally performed well, particularly flexible pipework

(polyethylene). Older galvanised pipe was more susceptible to damage, mostly in the areas

where significant ground movement occurred, mainly due to its inherent rigidity and

deterioration over time.

For most urban school sites the critical factor was the non-availability of water from the Council

supply.

In the immediate term this was managed by installing large plastic water tanks which were

filled by potable water. Ministry of Health guidelines required that these tanks be sterilised,

and filled with potable water. Water stored this way needed to be chlorine-dosed regularly to

maintain potability. In many sites once water supply from the Council system was restored,

tanks were drained and left onsite. This was a contingency measure to manage ongoing risk,

requiring only 24 hours stand-down time for sterilisation during the aftershock sequence. The

majority have now been removed.

6.2.2 Sewer

Older pipework systems, particularly earthenware and reinforced concrete were least able to

withstand ground movement. This was often compounded by pre-existing deterioration due to

age. These systems tended to pull apart easily, allowing groundwater and silt from liquefaction

to enter pipelines and clog them. Newer systems constructed with PVC have more material and

connective flexibility and were able to withstand a greater amount of ground movement while

remaining intact. At some sites with PVC pipework, even when pipe grades have flattened as a

result of pipe movement, sewer systems at the school have remained operational, providing a

reasonable level of service to the school.

For most urban schools, the critical factor was the damage to the Council sewer systems in the

street. This meant that even if pipework within the site had sustained little damage, schools

still needed emergency measures. This was managed by portaloos at some sites, while others

installed large sewage holding tanks (similar to the ones for water supply), which the school’s

wastewater was pumped into. These tanks were emptied frequently. Once Council sewer

service was restored to sites, some schools have retained the emptied tanks onsite as a

contingency measure to manage future risk.

6.2.3 Stormwater

The issues with stormwater are similar to those for sewerage, with the exception that temporary

measures for stormwater service were not implemented. Instead, schools with damaged




stormwater systems are experiencing more frequent ponding on site as water is less able to

drain away. This presents nuisance (puddles and mud) and slip hazards in winter (freezing).

Repairs to stormwater systems are potentially costly due to a combination of very old systems

still in existence, and the need to comply with current building code requirements. In the sites

with the most severe damage, replacement of the entire stormwater system is the only

compliant option, which can be expensive.

6.2.4 Hardstand

Options for hardstand repairs range from the ‘do minimum’ to ‘full design life’ approach, with the

former aimed at repairing superficial defects and restoring immediate levels of service but

accompanied by the risk of ongoing repairs. The ‘full design life’ approach involves full

remediation of the hardstand surface, specifically designed to mitigate against known risks (such as

liquefaction or lateral spread) by inclusion of engineering measures such as geotextiles and

geogrids, with the aim of lessening the cost of repair in a future earthquake event.

6.3 Block Specific Conclusions

6.3.1 Block Performance/Damage

The open plan blocks have minimal bracing which increases frame distortion and damage.

Some CEBUS type buildings have external nail plates that have failed during shaking without

resulting in collapse. These can be simply retrofitted.

One of the Pre-1930’s Two Storey Block’s has Potential Critical Structural Weaknesses while up

to 11 others have structural weaknesses.

7 Recommendations

Following this structural review, our recommendations for the Ministry have been separated into

three categories.

7.1 Site Considerations – Buildings and Infrastructure

The following items can be implemented immediately by the Ministry to reduce the risk during a

future emergency:

An egress and evacuation plan should be put in place for each school site. The main issues are

concerning stuck doors due to differential settlement and potential fall hazards. The assembly

point should also be considered.

Overhead falling hazards relating to poorly tied brick veneer, heavy building services or items

on shelving should be assessed, and if required secured or removed to a lower height.

Consideration should be given to assessing and, if required, strengthening, or removing the

veneer at height to mitigate this risk in a future significant earthquake event. Lowering the

veneer will have the added benefit of reducing the seismic load on the buildings’ structure and

improving its overall performance.

Consideration should be given to upgrading site infrastructure during significant

developments. This would reduce the extent of aged, frequently extended, brittle pipe networks

present on many school sites.




Consideration should be given to the assessment of schools’ existing infrastructure networks,

for their condition and capacity i.e. compliance and vulnerability. This would indicate a need

for the upgrade of any existing infrastructure with newer, more robust systems. This also

reduces the risk of major costs associated with repairing older systems, when repairs carried

out in the future might trigger the requirement for a Building Consent. Discussion with

Councils should also be considered to seek clarity on compliance requirements.

Consideration should be given to contingency measures for lifeline services (water supply &

sewer).

Consider options for hardstands that include ‘full design life’ to mitigate known geotechnical

risks.

7.2 Process

In addition to the items in section 7.1, the following items should be implemented by the Ministry

to improve the quality and consistency of additional design and remediation works throughout the

portfolio.

Issue minimum standard brief and guidelines for engineering assessment and design which

embodies current ‘best practice’. (We note that the Ministry have subsequently issued

guidelines on importance level for retrofit and new design).

Consider adopting damage resistant designs in high seismicity areas. This could also reduce

the cost to repair non-structural damage, which is estimated to be approximately 70% of the

total repair cost for commercial buildings.

Review processes around construction quality control and construction monitoring by the

designer and Territorial Authorities’ (TA’s) to ensure efficiency and confidence that the design

intent is achieved during construction.

Consider setting up a review panel, perhaps a continuation of the Engineering Strategy Group

(ESG) or similar to USA practice where an independent consultant from an approved panel

reviews design and or construction.

7.3 Further Review

This report has involved a review of existing Ministry documentation on a selection of typical

blocks. However other learnings from commercial and Ministry buildings should also be applied to

the portfolio, for example:

Stairs; review in accordance with Ministry of Business, Innovation and Employment (MBIE)

guidelines.

Precast panels; especially connections and requirements for ductility.

Shear walls; in line with interim design guidelines by Structural Engineering Society New

Zealand (SESOC).

Cross bracing; particularly Reid Brace especially connections and requirements for ductility.




8 Limitations

8.1 Other Site Risks

This assessment has only considered the hazards relating to earthquakes, and damage due to the

Canterbury earthquakes. There are other risks which should be considered by the MoE on a site

wide basis, including flooding, tsunami etc.

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings A1



Appendix A - School Building Types




Appendix A describes the typical school building types used in New Zealand which are not included

in the Catalogue of Standard School Building Types August 2013 and published by the MoE. A

brief description is provided to help identify these building types. The type names are not

consistent across the country, therefore a description is given along with photos and sketches of the

most distinctive details related to these types.

A1 Two Storey Classroom Block

This type of two storey building comprises of multiple classrooms with stair wells at the rear of the

building. They have large glazed northern walls. This block was usually built with a total of 12

classrooms per block, i.e. six classrooms on each level, however could also have ten classrooms in

total. The construction type is similar to the 1950s double storey comprising a reinforced concrete

and timber infill framing.

Figure 12 : Typical drawing of a 12 Classrooms Block Double Storey structure




A2 Subfloor Framing

This type of building was considered due to the foundation details. The purpose of a subfloor

braced framing foundation is to account for slope and uneven terrain.

Figure 13 : View of Subfloor Framing CEBUS block

Figure 14 : Typical sketch of a subfloor framing structure (taken from NZS 3604:2011)




A3 Pre 1930s Two Storey Block

This type of building is generally easily identified by the date of construction. The cladding is often

brick, which was popular at the time.

Figure 15 : Pre 1930s Two storey block plan view

Figure 16 : Front facade view of a Pre 1930s Two storey block

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings B1



Appendix B – Block Types by School




Schools Block ID Type Intensity zone Shirley Intermediate – 60 Shirley

Road, Shirley, Chch

Block 1 Open Air Veranda moderate

Wharenui Primary – 32 Matipo Street,

Riccarton, Chch

Block 1 & 2 Open Air Veranda moderate

Wairakei Primary – 250 Wairakei

Street, Bryndwr, Chch

Block 1,2 & 3 Open Air Veranda

low Learning Centre 1940s Single Storey

Weatherboard

Hammersley Park Primary – 90

Quinns Road, Shirley, Chch

Hall Hall with Sub-basement

under stage moderate Block 1 (Rooms 8-14) Dominion Block

Heathcote Valley Primary – Bridle

Path Road. Heathcote Valley, Chch

Block 2 (Rooms 1,2,3)

Junior Block

Open Plan Blocks

(Canterbury Education

Board) severe

Blocks 3, 5, 12 and 13

(Classrooms)

CEBUS Mk 1 and 2

Block 1 (Room 11&12) Canterbury Block

Banks Avenue Primary – 91 Banks

Avenue, Dallington, Chch

Block 2 (Rooms 15-22) Dominion Block

severe

Block 4 (Rooms 4-7) Canterbury Block

Block 6&8 (Rooms

1,2,13,14)

CEBUS Mk 1 and 2

Block 10 & 11 (Rooms 23-

27)

Prefabs – Paul Wilkin

Design

Fendalton Open Air School – 168

Clyde Road, Fendalton, Chch

Block 2 (Rooms 1-6) Open Plan Blocks


Board) moderate

Block 12 (Rooms 16-17) CEBUS Modified (1990)

Thorrington Primary – 22A Colombo

Street, Lower Cashmere, Chch

Block 1 Canterbury Block moderate




Schools Block ID Type Intensity zone Sumner Primary – 15 Colenso Street,

Sumner, Chch

Administration/Block 1

(Rooms 11-15)

Canterbury Block

severe

Block 19 Paul Wilkin Design

Hoon Hay Primary – 91 Sparks Road,

Hoon Hay, Chch

Block 8 CEBUS Mk 1 and 2

low Block 14 & 17 Portacom

Block 1-2 & 3 Canterbury Block

Freeville Primary – 1 Sandy Avenue,

North New Brighton, Chch

Learning studio 1 & 2

(Rooms 9-12)

Canterbury Block severe

Russley Primary – 75 Cutts Road,

Avonhead, Chch

Block 1 Canterbury Block

low Block 12 CEBUS Modified (1990)

Block 4 (Community Hall) Halls with Sub-basement

under stage

Darfield High – 16 Ross Street,

Darfield

Block 2 (Admins and rooms

9-12)

Canterbury Block severe

Heaton Intermediate – 125 Heaton

Street, Merivale, Chch

Block 2 & 4 1950s Double Storey

moderate Block 5 1940s Single Storey

Weatherboard

Manning Intermediate – 50 Hoon Hay

Road, Chch

Block 2 Twelve Classroom Double

Storey Block low

Branston Intermediate – 35 Amyes

Road, Hornby, Chch

Block 2 Twelve Classroom Double

Storey Block low

Shirley Primary – 11 Shirley Road.

Shirley, Chch

Block 2 Open Plan Blocks


Board) moderate

Block 10 CEBUS Mk 1

Block 8 (Rooms 9-12) Canterbury Block severe




Schools Block ID Type Intensity zone Central New Brighton Primary – 140

Seaview Road, New Brighton, Chch

Library Open Plan Blocks


Board)

Queenspark Primary – 222

Queenspark Drive, Parklands, Chch

3 of them Open Plan Blocks


Board)

moderate

Middleton Grange – 50 Acacia

Avenue, Riccarton, Chch

Block B Nayland

low

Van Asch Deaf Education Centre – 38

Truro Street, Sumner, Chch

Block K (Rooms 14-20) CEBUS Mk 1 and 2 severe

Avonside Girls’ High – 180 Avonside

Drive, Chch

Block A - 1927 Brick Pre 1930s 2 Storey

severe

Jobberns Block C 1950s Double Storey

Gresson Block B 1960s Nelson Block

straight block

Kaiapoi Borough Primary – 20 Hilton

Street, Kaiapoi

Hall Halls with Sub-basement

under stage severe

Linwood North – 221 Woodham Road,

Linwood, Chch

Hall Hall without Sub-

basement under stage severe

Burnside High – 151 Greers Road,

Burnside, Chch

No block number Portacom

low Block G (Block D

extension)

Nayland

Block B (Block E) 1960s Nelson "H Block"

Hagley Community College – 510

Hagley Avenue, Chch

Main Block Pre 1930s 2 Storey Block moderate




Schools Block ID Type Intensity zone Christchurch Boys’ High – Straven

Road, Riccarton, Chch

Block A (incl. library/audit

and classrooms wings)

Pre 1930s 2 Storey Block moderate

Papanui High – 30 Langdons Road,

Papanui, Chch

Block I (Block A) 1940s Single Storey

Weatherboard

moderate Block F (Plimsol) & Block

G or L (Library)

1960s Nelson Straight

Block

Block B (Hall) Secondary School Hall

Linwood College – 85 Aldwins Road,

Linwood, Chch

Library B1, Classroom

B1,B2, C1 & C2

1950s Double Storey

moderate Block F 1960s Nelson "H Block"

Cashmere High – 172 Rose Street,

Somerfield, Chch

Performing art Centre Secondary School Hall

moderate Block S 1960s Nelson "H Block"

Block A & B 1950s Double Storey

Rangiora High – 125 East Belt,

Rangiora

Block C,D,E 1950s Double Storey low

Mairehau High – 440 Hills Road,

Mairehau, Chch

Tennant Block 1960s Nelson "H Block"

moderate Block F Nelson Single Storey

Cartwright block 1960/70s Single storey

weatherboard

Lincoln High – 25 Boundary Road,

Lincoln

Block D (LHS block C) 1960/70s Single storey

weatherboard low Block D Nelson Single Storey

Hall Secondary School Hall




Schools Block ID Type Intensity zone Shirley Boys High – 59 North Parade,

Shirley, Chch

Block F 1960/70s Single storey

weatherboard moderate Block E Nelson Single Storey

Kaiapoi High – 101 Ohoka Road,

Kaiapoi

First stage S68 (Schools 1968) and

MKII in 1972 severe

Second stage S68 (Schools 1968) and

MKII in 1972

Hornby High – 180 Waterloo Road,

Hornby, Chch

Block D,E,F S68 (Schools 1968) and

MKII in 1972 low

Avonhead Primary – 55 Avonhead

Road, Avonhead, Chch

Block 2 - Hall Hall without Sub-

basement under stage low

St Martins Primary – 24 Albert

Terrace, St Martins, Chch

Room 26-27 CEBUS with Subfloor

Framing moderate

Mt Pleasant Primary – 82 Major

Hornbrook Road, Mt Pleasant, Chch

Room 9 CEBUS with Subfloor

Framing severe

Bamford Primary – 6 Gould Crescent,

Woolston, Chch

Block 2 Dominion Block severe

Addington Primary – 22 Brougham

Street, Addington, Chch

Block 1 & 5 Dominion Block moderate

Bromley Primary – 33 Keighleys

Road, Bromley, Chch

Block 2 library Dominion Block severe

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings C1



Appendix C – Building Type Performance

Summary



C1 Open Air Veranda block

Typical photos Observed Damage Damage Description

Shirley Intermediate Shirley Intermediate

Cracking in weatherboard; sign of frame movement.

Wairakei School Wairakei School

Cracking of foundation

Building #1 Shirley Intermediate

Liquefaction Zone Blue

Intensity level High

Rating 3

Building #2 Wharenui School

Liquefaction Zone Yellow


Rating 2

Building #3 Wairakei School


Intensity level Low

Rating 2

C1.1 Recommendations & Conclusions

The rating of 3 for Shirley Intermediate is predominantly due to ground deformation. The connection of the

sub-floor framing to the building was assessed to be 11%NBS. Once this is addressed the building is assessed

to be greater than 34%NBS.




C2 Dominion block


Banks Avenue

Banks Avenue

Rocking of Brick

Banks Avenue

Building #1 Banks Avenue

Liquefaction Zone Red


Rating 5

Building #2 Hammersley Park


Intensity level Moderate

Rating 3


The brick veneer on the Dominion Block at Banks Avenue School had to be removed. Liquefaction caused

differential settlement at various locations. The Dominion Block has a plan irregularity (structural weakness)

due to the full length windows on one side of building. This weakness results in excessive deformation which

causes the brick veneer to become a falling hazard.




C3 Canterbury block


Sumner School

Thorrington School

Minor cracking in block veneer

Hoon Hay School

Russley School

Moderate damage to the summerhill stone veneer walls. Mostly occurs in the concrete masonry.

Building #1 Thorrington School Building #5 Banks Avenue

Liquefaction Zone Yellow Liquefaction Zone Red

Intensity level High Intensity level High

Rating 4 Rating 2

Building #2 Heathcote Valley School Building #6 Russley School

Liquefaction Zone Yellow Liquefaction Zone Grey

Intensity level Severe Intensity level Low

Rating 1 Rating 2

Building #3 Hoon Hay School Building #7 Darfield

Liquefaction Zone Yellow Liquefaction Zone N/A


Rating 2 Rating 3

Building #4 Freeville School Building #8 Sumner

Liquefaction Zone Red Liquefaction Zone Yellow

Intensity level Low Intensity level Severe

Rating 2 Rating 1

Building #9 Central New Brighton



Rating 2





The Hoon Hay School buildings (Block 1,2 & 3) were retrofited in 1989 (built in 1960) and the Thorrington

School Block 1 was built in 1957 and retrofitted in 1962. The damage to the Thorrington block is mostly due

to ground deformation.

The Canterbury Block has plan irregularity which is defined as a structural weakness. The type of

damage noted was consistent and the brick veneer became a falling hazard. These blocks have

generally performed better than the assessed capacity of 20-30%NBS, depending on the number of

adjoined blocks.




C4 12 Classrooms double storey Block


Manning Intermediate

Manning Intermediate

Slabs not level in various areas of the classroom block

Building #1 Manning Intermediate



Rating 2

Building #2 Branston Intermediate School

Liquefaction Zone Grey

Intensity level Low

Rating 3


The samples for this building type are in low and moderate intensity zones, and so limited conclusions can be

drawn as to this building type's seismic performance. Irregular wall layout may be a structural weakness.

This could explain the rating of 2 in a low intensity zone. Further data for other buildings of this block type in

a zone of higher ground shaking would assist in assessing the performance of this block.




C5 Open Plan Block


Heathcote Valley School

Heathcote Valley School

Moderate structural damage to the wall and significant frame distortion. Lateral translation of slab at joint with adjoining part of building.

Queenspark School

Fendalton Open Air School

Movement to wall and ceiling linings at sheet edge.

Building #1 Shirley Primary School Building #4 Heathcote Valley

Liquefaction Zone Blue Liquefaction Zone Yellow

Intensity level High Intensity level Severe

Rating 2 Rating 3

Building #2 Fendalton Open air School Building #5 Queenspark School


Intensity level Moderate Intensity level Low

Rating 2 Rating 2

Building #3 Central New Brighton



Rating 1


This block has large open spaces with minimal internal bracing walls. The roof does not act as a diaphragm

and so is not effective at distributing roof loads evenly throughout the structure to the bracing walls. This

results in increased frame distortion which has caused some windows to break. The large open space,

minimal bracing, ineffective roof diaphragm resulting in increased deformation is considered to be a

structural weakness.




C6 CEBUS MK 1 & 2


Hoon Hay School

Pavement cracking outside and minor evidence of frame distortion part of building.

Banks Avenue

Hoon Hay School

Building #1 Banks Avenue Building #3 Shirley Primary School

Liquefaction Zone Red Liquefaction Zone Blue


Rating 1 Rating 1

Building #2 Hoon Hay School Building #4 Van Asch School

Liquefaction Zone Yellow Liquefaction Zone Yellow

Intensity level High Intensity level Severe

Rating 2 Rating 2


CEBUS of building has a simple design with a portal frame bracing system. This type of building performed

well and no critical structural weakness has been identified. Attention should be paid to the condition of the

gangnail plates which provide the connection at the external frame connections. These have been seen to

become loose over time and become ineffective during repeated cycles of earthquake shaking.




C7 CEBUS Modified (1990)


Russley School

Fendalton Open Air School

Some ceiling panels damaged

Building #1 Fendalton Open air School



Rating 1

Building #2 Russley School


Intensity level Low

Rating 1


The samples for this building type are both in the lower intensity zones, limited conclusions can be drawn as

to the seismic performance of this building type. Further data for buildings in a zone of higher intensity of

ground shaking would be beneficial to their overall assessment. Both the superstructure and foundations

were assessed to be approximately 90%NBS.




C8 Prefabs - Paul Wilkin Design


Sumner School

No photos taken Some foundation settlement

Typical timber truss system

Building #1 Banks Avenue

Liquefaction Zone Red


Rating 2

Building #2 Sumner School


Intensity level Severe

Rating 1


This type of building performed well, even when subjected to ground movement. The foundations were easily

re-levelled. Where necessary, the building can be lifted to enable new foundations to be constructed.




C9 Nayland Block


Middleton Grange School

No photos taken Some minor cracking

Discover School Halswell (not part of this assessment)

Building #1 Middleton Grange School



Rating 1

Building #2 Burnside High School


Intensity level Low

Rating 2


The samples for this building type are in the low and moderate intensity zones and so limited conclusions can

be drawn as to the seismic performance of this building type. The nearest ground shaking information

generally showed no to minor ground damage and so further data from a zone of higher intensity ground

shaking would be beneficial in the assessment of this block.




C10 Hall with Sub-basement


Hammersley Park School

xvxcxcxxczxc Russley School

The hall has sustained some minor damage, such as hariline cracking to a soffit cladding panel and minor movement of internal GIB linings.

Hammersley Park School

Building #1 Kaiapoi Borough School



Rating 2

Building #2 Russley Primary School


Intensity level Low

Rating 2

Building #3 Hammersley Park School



Rating 2


This type of hall with a sub-basement under the stage has plan and vertical irregularity. This is a structural

weakness due to the tendency of the two sections of building to respond to the earthquake shaking

differently.




C11 Hall without Sub-basement


Linwood North School


Moderate crack in foundation on the eastern side. Foundation has dropped.


Windows broken.

Building #1 Avonhead School


Intensity level Low

Rating 2

Building #2 Linwood North school



Rating 3


This type of hall does not have any particular structural weaknesses. Primary school halls tend to be

smaller, and so roof diaphragm action and wall bracing will provide additional bracing. Lightweight cladding

materials reduce the seismic demand on the structure.




C12 Portacom


Hoon Hay School

Hoon Hay School

Minor frame distortion and evidence of floor subsidence.

Hoon Hay School

Building #1 Burnside High School


Intensity level Low

Rating 1

Building #2 Hoon Hay School



Rating 2


This type of building performed well when subjected to ground movement, and the foundations were easily

relevelled.




C13 Subfloor Framing


Mt Pleasant School

St Martins School

Out of plumb piles under the Room 27 building. The lateral displacement is observed to be over 50mm.

St Martins School

St Martins School

One bearer has cracks over the top of the pile.

Building #1 St Martins School



Rating 3

Building #2 Mt Pleasant School

Liquefaction Zone N/A

Intensity level Severe

Rating 3


This type of foundation performed well but has been highlighted to demonstrate the importance of

subfloor framing and its correct installation. The connection details between the foundation and

the structure are critical. If large ground deformations or intense shaking occur, the connections

could fail, resulting in movement between the structure and the foundation. Both buildings had a

combination of ground deformation and shaking.




C14 Pre 1930s 2 Storey Block


Christchurch Boys High School

Avonside Girls High School

Major vertical cracks right through the building (around the perimeter wall). One masonry lintel beam has large shear cracks between Rm 37 and adjacent hallway



Out of plane failure at apex - N elevation (masonry veneer). Minor cracking to internal plaster at wall/ceiling joints.

Building #1 Hagley community College



Rating 2

Building #2 Avonside Girl's High School

Liquefaction Zone Orange


Rating 4

Building #3 Christchurch Boys' High School



Rating 2





The Pre-1930s Two Storey Block at Avonside Girl's High School was retrofitted by adding

reinforced concrete walls and steel beams attached to the brick facades. Extensive damage to the

brick facade was due to ground deformation. The damage to this block at Christchurch Boys High

School was mostly due to differential settlement which made doors unable to be opened properly.

In the case of the Hagley Park Comunity Centre, the main structural weakness is the difference in

construction between the two sections of the building. In general, these buildings built in the 1930s

are likely to have critical structural weaknesses such as unreinforced brick walls that present a

falling hazard. Strengthening works carried out in the 1990s were aimed at addressing the

earthquake prone building issues which explains their relatively good performance.




C15 1940s Single Storey Weatherboard Block


Heaton Normal Intermediate School


Moderate structural damage. Cracking to ceiling, corniche and concrete beams.

Wharenui school


West corner of building appears to have some settlement under one pile.

Building #1 Papanui High school


Intensity level Low

Rating 2

Building #2 Heaton Normal intermediate School



Rating 3

Building #3 Wairakei School


Intensity level Low

Rating 1


This type of one storey building performs well under seismic loads. It is a lightweight and low building.

However at Heaton Normal Intermediate, ground deformation caused significant damage to the foundation

causing cracking throughout the structure.




C16 1950s Double Storey


Linwood College

Linwood College

Severe damage to the columns in corridor. Shear craking just below the beam junction.

Avonside Girl’s High School

Linwood College

Seismic joint opened up and cover plate damaged with 100mm gap between adjacent block.

Building #1 Linwood College Building #2 Rangiora High School

Liquefaction Zone Blue Liquefaction Zone N/A

Intensity level High Intensity level Low

Rating 3 Rating 2

Building #3 Cashmere Building #4 Avonside Girls’ High School

Liquefaction Zone Yellow Liquefaction Zone Orange


Rating 3 Rating 4


There is insufficient bracing in the longitudinal direction due to the clerestory windows between the concrete

columns. This is a structural weakness which results in significant damage to beams and columns.




C17 1960s Nelson Block "Straight"




Separation around frames and windows.



Severe liquefaction caused differential settlement of 50mm approx. and lateral spreading. The perimeter walls settled.

Building #1 Avonside Girl's High School

Liquefaction Zone Orange


Rating 4



Intensity level Low

Rating 1


One side of the building consists of two storeys of window openings with masonry veneer beneath the ground

floor windows. This plan irregularity could be a structural weakness. In addition, two structural weaknesses

found at the Avonside Girl's High School are a lack of complete diaphragm and connections to structure at 1st

floor level, and a lack of restraint to the concrete staircase in longitudinal direction. It should be noted that

the Avonside school building has had retrofitting to improve the performance of the brick walls. The

strengthening works carried out in the 1990s and 2000s aimed to address most earthquake prone building

issues which explains their relatively good performance.




C18 1960s Nelson Block "H Plan"


Linwood College

Cashmere High School

The school is no longer level due to differential settlement.

Building #1 Burnside High School Building #3 Mairehau High

Liquefaction Zone Grey Liquefaction Zone Yellow

Intensity level Low Intensity level Moderate

Rating 2 Rating 1

Building #2 Linwood College Building #4 Cashmere High



Rating 1 Rating 3


The Cashmere High school rating of 3 is mostly due to ground deformation. Burnside High school which had

not undergone much shaking but still had cracking caused by differential settlement. Otherwise, this type of

structure seems to have withstood shaking quite well. The combination of one and two storeys and different

construction materials can result in structural weaknesses. The strengthening works carried out in the 1990s

and 2000s aimed to address most structural weaknesses which explains their relatively good performance.




C19 Nelson Single Storey


Shirley Boys High School


Cracking and spliting between two parts of building


Building #1 Lincoln High School



Rating 1

Building #2 Mairehau High school



Rating 1

Building #3 Shirley Boys High School



Rating 3


This lightweight building has generally performed well. Most of the damage recorded was due to ground

deformation. A structural weakness may be the lack of bracing between the windows.




C20 S68 (school 68-72)


Kaiapoi High School

Kaiapoi High School

Minor cracks observed in door lintel adjacent internal courtyard on two-storey side of courtyard. Masonry block loose on left hand side of doorway on East courtyard elevation.

Kaiapoi High School

Kaiapoi High School

Minor cracks observed in door lintel adjacent internal courtyard on two-storey side of courtyard. Masonry block loose on left hand side of doorway on East courtyard elevation.

Building #1 Kaiapoi High School



Rating 3

Building #2 Hornby High School


Intensity level Low

Rating 1


This one storey building has a structural weakness due to the unreinforced blockwork walls. The damage that

occurred to the Kaiapoi school building is mostly due to ground deformation.




C21 Secondary School Hall


Cashmere High School

No damage found

Building #1 Lincoln High School



Rating 1



Intensity level Low

Rating 1

Building #3 Cashmere High School



Rating 1


The samples for this building type are in the low and moderate intensity zone, limited conclusions can

therefore be drawn as to this building type's seismic performance. Further data for other buildings of this

type in a zone of higher intensity would be beneficial.

Canterbury Earthquakes – Impact on the Ministry of Education’s School Buildings D1



Appendix D – Geotechnical Description of

School Standard Blocks




Table of Results – Geotechnical Description

Table D.1 presents the observed ground damage made available by the Canterbury Geotechnical

Database. The information presented in this database in the form of a Google Earth map is almost

entirely associated with residential properties. Therefore, the information presented is essentially a

summary of the behaviour of the residential sites surrounding the school properties.

Where no damage was observed, no entry was made in the table. In most cases where the lateral

spread at the specified school site or that of the surrounding areas has been identified, ground

cracking was also seen.

The information shown in Table D.1 below regarding the Ministry of Education Geotechnical

Classification was obtained from the Ministry of Education whilst some information was provided

from the assessments carried out by Opus Geotechnical.

Table D.1 - Schools and their respective standard blocks

School Block Type Ground Damage Observed Rating

Addington Primary Dominion - *

Avonhead Primary Hall without Sub-

basement - 2

Avonside Girls

Pre 1930’s 2 Storey

1950’s Double Storey

1960’s Nelson

“Straight”

September

Lateral Spread: None to major

observed

Ejected liquefiable material: Often

observed

February

Lateral spread: Moderate to major


observed

4

4

4

Bamford Primary

CEBUS 5

Open Air Verandah

CEBUS 5

February

Lateral Spread: Moderate to major


observed

Ground cracking: Minor

3

*

*




Banks Avenue Primary

Dominion

Canterbury

CEBUS 2

Prefabs

Paul Wilkin Design

September


Lateral spread: Severe (across the

river)


observed (across the river)

February


observed


1

*

*

Branston Intermediate Twelve Classroom

Double Storey

February

No site information. Site is west of the

CBD. Closest site information

generally shows no obvious ground

damage with only small scattered

areas of :



observed

3

Bromley Primary CEBUS 5

Open Plan

February

Ejected liquefiable material: Minor to

moderate

*

Burnside High

Nayland

Portacom

1960’s Nelson “H

Plan”

No liquefaction or lateral spread.

2

1

2

Cashmere High



Plan”

Secondary School Hall

Canterbury

February


moderate to the north

3

3

1

2




Central New Brighton Primary Open Plan - 1

Christchurch Boys’ High Pre 1930’s 2 Storey - 2

Christchurch South Intermediate Portacom

February

Ejected liquefiable material: Large

quantities

-

Fendalton Open Air Primary Open Plan

CEBUS Modified

September

No site information. Nearby area

experienced:


February



observed

2

1

Freeville Primary Canterbury

February


quantity

2

Hagley Community College Pre 1930’s 2 Storey

February


moderate

2

Hammersley Park Primary

Dominion

Hall with Sub-

basement

February



observed

3

2

Heathcote Valley Primary

Canterbury

Open Plan

CEBUS 2

CEBUS 1

Paul Wilkin Design

-

1

3

*

*




Unit Classroom

Heaton Normal Intermediate


Weatherboard


February



large

3

3

Hoon Hay Primary

Canterbury

CEBUS 2

Portacom

CEBUS (various)

September



moderate

February


moderate

2

2

2

2

Hornby High S68 (School 68-72)

No site information. Site to the west

of CBD. Closest site information

shows generally no to minor ground

damage.

1

Kaiapoi Borough Primary

Hall with Sub-

basement

CEBUS (various)

September

No site information. Closest sites

experienced:

Ground cracking: None to

minor

Lateral spread: Moderate to

major

Ejected liquefiable material:

Large quantities

2

*

Kaiapoi High S68 (School 68-72) - 3

Kaiapoi North Primary CEBUS (various)

Canterbury

- *

Lincoln High GC1

No site information. Site to the south-

west of CBD. Closest site information

shows no to minor ground damage

observed.

1

1




Linwood College



Plan”

February


moderate

3

1

Linwood North Primary Hall without Sub-

basement

February


quantities

3

Lyttelton Main Open Air Verandah

Dominion

GC2 *

Mairehau High 1960’s Nelson “H

Plan”

February


moderate

1

1

Manning Intermediate Twelve Classroom

Double Storey

September



moderate

February


moderate

2

Middleton Grange Nayland

No site information. Site is to west of

CBD. Closest site information shows

no to minor ground damage.

1

Mt Pleasant Primary Subfloor Framing - 3

Papanui High


Weatherboard

1930’s Nelson

“Straight”

Secondary School Hall


CEBUS (various)

September

No site information but surrounding

suburbs generally experienced:



moderate

February

2

*

1

*

*




Nelson Library Ejected liquefiable material: None

observed

Queenspark Primary Open Plan

September

Ground cracking: None observed

Ejected liquefiable material: None

observed

February



moderate

2

Rangiora High 1950’s Double Storey - 2

Russley Primary

Canterbury

CEBUS Modified

(1990)

Hall with Sub-

basement

No site information. Site is north-west

of CBD with no to minor ground

damage.

2

1

2

Shirley Intermediate Open Air Verandah

September

Surrounding sites experienced no

observed damage.

February


moderate

3

Shirley Primary Open Plan

CEBUS 2

September


observed damage.

February


quantities

2

1

Shirley Boys’ High 1960-70’s Single

Storey Weatherboard

September


observed damage.

3




February



observed

St Martin’s Primary

Subfloor Framing

Open Air Verandah

CEBUS 1

CEBUS 4

-

3

*

*

*

Sumner Primary

Canterbury

Paul Wilkin Design

CEBUS (various)

Canterbury (modified)

-

1

1

*

*

Thorrington Primary Canterbury Block

February




quantities

4

Van Asch Deaf Education Centre CEBUS 2

CEBUS (various)

-

2

*

Wairakei Primary

Open Air Verandah


Weatherboard

September

No site information but adjacent areas

experienced:



moderate

2

1

Wharenui Primary Open Air Verandah

Site lies to near-west of CBD which

generally experienced no to minor

ground damage.

2




Woolston Primary Aranui Block

CEBUS 3

February


moderate

*

* These ratings are based on the DEE summary report as no primary source information is available.

Opus International Consultants Ltd 20 Moorhouse Avenue PO Box 1482, Christchurch Mail Centre, Christchurch 8140 New Zealand t: +64 3 363 5400 f: +64 3 365 7858 w: www.opus.co.nz

Documents

Ministry of Education Canterbury Earthquakes€¦ · Christchurch earthquakes (September 2010, February 2011 and June 2011) on the Ministry’s school buildings and infrastructure