Geotechnical Completion Report Knights Stream Park Stage3A Development (Lots 107 to 148)

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1 Aurecon New Zealand Limited Unit 1, 150 Cavendish Road Casebrook Christchurch 8051 PO Box 1061 Christchurch 8140 New Zealand T F E W christchurch@aurecongroup.com aurecongroup.com 5 June 2013 Greg Dewe Land Development Manager Fulton Hogan Land Development Limited 29 Sir William Pickering Drive PO Box Christchurch 8545 Dear Greg Geotechnical Completion Report Knights Stream Park Stage3A Development (Lots 107 to 148) This geotechnical completion report is submitted in accordance with Section of the Christchurch City Council Infrastructure Design Standard. Introduction Fulton Hogan Land Development Limited (FHLD) is in the process of developing the Knights Stream Park Residential development in Halswell in southwest Christchurch, with Stage 3A of the development nearing completion. During the geotechnical investigation stage of Stage 3A parts of development were identified as being susceptible to a varying degree to the effects of seismically induced liquefaction. Please see attached plan for the extent of Stage 3A. The liquefaction risk at the site was assessed as being with acceptable levels that a Technical Category 2 (TC2) classification of the site was applicable. As such no site specific liquefaction mitigation measures have been implemented in the site development. The conditions of Aurecon s engagement are as per our original agreement relating to initial geotechnical investigation carried in October 2010, and are set out in our letter of engagement dated 29 September Previous Investigation Aurecon undertook a geotechnical site investigation across the wider FHLD Halswell West residential development site in October 2010 to support a plan change application of the wider 117ha site. This geotechnical investigation comprised of: Mapping of observed surface manifestation of liquefaction following 4 September 2010 Darfield Earthquake. 25 Piezocone Penetrometer Tests (CPTu) undertaken by McMillan specialist Drilling and supervised by a Geotechnical Engineer from Aurecon. A review of nine borehole logs from boreholes drilled under the supervision of Davie Lovell- Smith Limited (the project Civil Engineer). A review of the Environment Canterbury GIS system for borehole logs within the direct vicinity of the site. A review of ground water levels recorded in six standpipe piezometers installed by Davie Lovell-Smith Limited in 2007 and regularly monitored for 2.5 years. Project File Let KSP 3A 224 Sign Off Geotech Rev1.docx 5 June 2013 Revision 1 Page 1

2 This investigation is described in the Aurecon Report Geotechnical Site Investigation and Liquefaction Assessment, Halswell West Rezoning, Fulton Hogan Land Development Limited, Rev1 dated 29 November 2010 (Aurecon, 2010). In the days immediately following the 22 February 2011 Christchurch Earthquake Aurecon undertook a site walk over and mapping of surface manifestation of liquefaction across the entire Halswell West development (including Knights Stream Park Stage 3A). Aurecon undertook a geotechnical investigation to support a subdivision application for Stage 3 of the Knights Stream Park development between October 2011 to March This included testing in areas that are now included in Stage 3A. This geotechnical investigation comprised: Nine Cone Penetrometer Tests (CPT) undertaken by McMillan Specialist Drilling. Excavate and log 18 exploratory test pits. This investigation is described in the Aurecon Report Geotechnical Site Investigation and Liquefaction Assessment, Knights Stream Park Stage 3, Fulton Hogan Land Development Limited, Rev2 dated 18 March 2012 (Aurecon, 2012a). As part of the geotechnical investigation for Stages 6 and 7 of the Knights Stream Park (directly adjacent to Stage 3) a further four CPT tests were undertaken around the edge of the stormwater basin that is located on the southwest edge of Stage 3A. This investigation is described in the Aurecon Report Geotechnical Site Investigation and Liquefaction Assessment, Knights Stream Park Stages 6 and 7, Fulton Hogan Land Development Limited, Rev1 dated 29 October 2012 (Aurecon, 2012b). Liquefaction Hazard Assessment The site experienced minor surface manifestations of seismically induced liquefaction following the 4 September 2010 Darfield Earthquake and none was observed following the 22 February 2011 Christchurch Earthquake. A liquefaction hazard assessment was carried out as part of the site assessments using the method prescribed in the Department of Building and Housing (DBH) now the Ministry of Business, Innovation, and Employment (MBIE) for residential development in Canterbury following the Canterbury earthquake sequence (DBH, 2011). Technical Category Classification We have assessed the liquefaction hazard at the site using the method recently prescribed by MBIE guidelines, observed site performance during the major seismic events in the Canterbury earthquake sequence. Based upon the recorded groundwater level information from DLS and our geotechnical site investigations using the liquefaction hazard assessments we believe the Lots 107 to 148 fulfil the requirements of TC2 Classification, i.e. this effectively means that the MBIE believe that Minor to moderate land damage from liquefaction is possible in future significant earthquakes. House foundations are required in accordance with the MBIE (2012) Repairing and rebuilding houses affected by the Canterbury earthquakes released in December References Aurecon, Geotechnical Site Investigation and Liquefaction Assessment, Halswell West Rezoning, Fulton Hogan Land Development Limited, Revision 1 - dated 29 November Aurecon New Zealand Limited, Christchurch, New Zealand. Project File Let KSP 3A 224 Sign Off Geotech Rev1.docx 5 June 2013 Revision 1 Page 2

3 Aurecon, 2012a. Geotechnical Site Investigation and Liquefaction Assessment, Knights Stream Park Stage 3, Fulton Hogan Land Development Limited, Rev2 dated 18 March Aurecon New Zealand Limited, Christchurch, New Zealand. Aurecon, 2012b. Geotechnical Site Investigation and Liquefaction Assessment, Knights Stream Park Stages 6 and 7, Fulton Hogan Land Development Limited, Rev1 dated 29 October Aurecon New Zealand Limited, Christchurch, New Zealand. DBH, Revised guidance on repairing and rebuilding houses affected by the Canterbury earthquake sequence. Department of Building and Housing, Wellington, New Zealand. MBIE, Repairing and rebuilding houses affected by the Canterbury earthquakes. Ministry of Business, Innovation and Employment, Wellington, New Zealand. Limitations We have prepared this report in accordance with the brief as provided. The contents of the report are for the sole use of the Client and no responsibility or liability will be accepted to any third party. Data or opinions contained within the report may not be used in other contexts or for any other purposes without our prior review and agreement. The recommendations in this report are based on data collected at specific locations and by using suitable investigation techniques. Only a finite amount of information has been collected to meet the specific financial and technical requirements of the Client s brief and this report does not purport to completely describe all the site characteristics and properties. The nature and continuity of the ground between test locations has been inferred using experience and judgement and it must be appreciated that actual conditions could vary from the assumed model. Subsurface conditions relevant to construction works should be assessed by contractors who can make their own interpretation of the factual data provided. They should perform any additional tests as necessary for their own purposes. Subsurface conditions, such as groundwater levels, can change over time. This should be borne in mind, particularly if the report is used after a protracted delay. This report is not to be reproduced either wholly or in part without our prior written permission. This conclusions in this report draws on investigations, analysis and conclusions from various investigations stages and numerous reports. For specific details please refer to the above mentioned references or contact the writers. Project File Let KSP 3A 224 Sign Off Geotech Rev1.docx 5 June 2013 Revision 1 Page 3

4 If you have any queries regarding the content of this letter, please do not hesitate to contact the undersigned. Yours sincerely Dr Jan Kupec PhD MSc canding MIPENZ CPEng IntPE MRSNZ NZGS IGS ISSMGE NZSEE Chartered Professional Geotechnical Engineer Technical Director Inc: Knights Stream Park Stage 3A Site Layout Plan CC: Andy Hall, Davie Lovell-Smith Ltd, PO Box 679, Christchurch Project File Let KSP 3A 224 Sign Off Geotech Rev1.docx 5 June 2013 Revision 1 Page 4

5 Fulton Hogan Land Development Limited Reserve m² m² m² m² m² m² m² 480m² 463m² A B E R D A R E S T R E E T m² m² m² m² m² (0) m² m² K R U G E R R O A D Kiosk m² m² 33.5 (0) m² 469m² m² E L B A C R E S m² E L B A C R E S C E N T m² m² R I C H M O N D A V E N U E m² m² m² +45m² ROW 568m² m² +45m² ROW 659m² 28.7 W H I N C O P S R O A D LEGEND DENSITY A " The long term name you can trust " DENSITY B DENSITY C Note: Areas and dimensions are subject to final survey and deposit of plans. J:\16011\Subcon\Website Sale Plans\E18022.KS Stage 3A r2.dwg