A photograph of a UC Geology student inspecting damage to the club rooms at Bexley Park.
A map showing the extent of liquefaction-related land damage in Christchurch.
This is an interim report from the research study performed within the NHRP Research Project “Impacts of soil liquefaction on land, buildings and buried pipe networks: geotechnical evaluation and design, Project 3: Seismic assessment and design of pipe networks in liquefiable soils”. The work presented herein is a continuation of the comprehensive study on the impacts of Christchurch earthquakes on the buried pipe networks presented in Cubrinovski et al. (2011). This report summarises the performance of Christchurch City’s potable water, waste water and road networks through the 2010-2011 Canterbury Earthquake Sequence (CES), and particularly focuses on the potable water network. It combines evidence based on comprehensive and well-documented data on the damage to the water network, detailed observations and interpretation of liquefaction-induced land damage, records and interpretations of ground motion characteristics induced by the Canterbury earthquakes, for a network analysis and pipeline performance evaluation using a GIS platform. The study addresses a range of issues relevant in the assessment of buried networks in areas affected by strong earthquakes and soil liquefaction. It discusses performance of different pipe materials (modern flexible pipelines and older brittle pipelines) including effects of pipe diameters, fittings and pipeline components/details, trench backfill characteristics, and severity of liquefaction. Detailed breakdown of key factors contributing to the damage to buried pipes is given with reference to the above and other relevant parameters. Particular attention is given to the interpretation, analysis and modelling of liquefaction effects on the damage and performance of the buried pipe networks. Clear link between liquefaction severity and damage rate for the pipeline has been observed with an increasing damage rate seen with increasing liquefaction severity. The approach taken here was to correlate the pipeline damage to LRI (Liquefaction Resistance Index, newly developed parameter in Cubrinovski et al., 2011) which represents a direct measure for the soil resistance to liquefaction while accounting for the seismic demand through PGA. Key quality of the adopted approach is that it provides a general methodology that in conjunction with conventional methods for liquefaction evaluation can be applied elsewhere in New Zealand and internationally. Preliminary correlations between pipeline damage (breaks km-1), liquefaction resistance (LRI) and seismic demand (PGA) have been developed for AC pipes, as an example. Such correlations can be directly used in the design and assessment of pipes in seismic areas both in liquefiable and non-liquefiable areas. Preliminary findings on the key factors for the damage to the potable water pipe network and established empirical correlations are presented including an overview of the damage to the waste water and road networks but with substantially less detail. A comprehensive summary of the damage data on the buried pipelines is given in a series of appendices.
A photograph captioned by Paul Corliss, "Avonside and Retreat Roads post earthquake".
A photograph of a damaged residential property at Seabreeze Close in Bexley. The yard is covered with weeds and silt from liquefaction.
Liquefaction covers the driveway of these residential properties on Seabreeze Close, Bexley.
Liquefaction is still evident at this abandoned residential section on Seabreeze Close, Bexley.
A photograph of several earthquake-damaged houses on Chester Street East. A pile of liquefaction silt is on the footpath in the foreground.
Liquefaction and building rubble on the damaged footpath outside the former Public Library.
Liquefaction and building rubble on the damaged footpath outside the former Public Library.
Silt from liquefaction and road damage around businesses on Ferry Road in Woolston.
Silt from liquefaction and road damage around businesses on Ferry Road in Woolston.
Liquefaction and building rubble on the damaged footpath outside the former Public Library.
Liquefaction and flooding in Waitaki Street, Bexley. The photographer comments, "Waitaki Street a week after the Christchurch Earthquake. Because of the damage to the drains and liquefaction in the area the streets are not drying out".
A large crack on the side of a residential road in Avonside. Cones have been placed on the crack to warn road users. In the background, piles of liquefaction have been dug out of residential properties and placed on the road for collection.
Liquefaction in North New Brighton. The photographer comments, "This was the liquefaction pouring out of a split in the road where it joins the side-walk. The quakes felt pretty violent, but the damage was less severe than the February one. Unlucky for me the epicentre was only 9.6km away and smaller aftershocks were a lot closer".
Extensive damage caused by liquefaction in Bracken Street, Avonside. A pile of liquefaction can be seen in front of this house. After the earthquake, many people had to dig this silt out of their properties and place it on the road to be collected.
Photograph captioned by Fairfax, "Earthquake in Christchurch. Damage and liquefaction around the city's boundary".
A photograph captioned by BeckerFraserPhotos, "A damaged residential property at Seabreeze Close in Bexley. The yard is covered with weeds and silt from liquefaction".
Liquefaction silt which has been partly cleared from in front of businesses on Ferry Road. A damaged part of the footpath has also been filled in with gravel.
A photograph of a damaged house. The photograph is captioned by Paul Corliss, "The block of Bexley and Pages Roads".
Road damage and liquefaction in a residential street. The photographer comments, "A great gouge in the road caused by liquefaction undermining the road surface and a car driving over it. This was the earthquake in Christchurch, New Zealand on 22 February 2011".
A photograph of police and members of the public people standing near the earthquake damaged Smiths City car park after the 22 February 2011 earthquake. Liquefaction covers the right side of the footpath.
A photograph of police and members of the public people standing near the earthquake damaged Smiths Citys car park after the 22 February 2011 earthquake. Liquefaction covers the right side of the footpath.
Photograph captioned by BeckerFraserPhotos, "23 Seabreeze Close, Bexley. The view through the window shows how much liquefaction collected in the garage".
A digitally manipulated image of broken objects. The photographer comments, "Digital painting of breakages and liquefaction after the February 22 earthquake in Christchurch".
Photograph captioned by BeckerFraserPhotos, "Kerrs Reach rowing facility".
A photograph captioned by Paul Corliss, "Avonside and Retreat Roads post earthquake".
A photograph of detail of a damaged house. The photograph is captioned by BeckerFraserPhotos, "Seabreeze Close, Bexley".
A view across Armagh Street to several damaged buildings including the Croydon House Bed and Breakfast Hotel. Liquefaction has covered the footpath and the houses have been cordoned off with emergency tape.