
Overview of the Presentation Jarg: • The seismic context & liquefaction Tom: • Potable Water Supply • Waste Water Network
Photograph captioned by BeckerFraserPhotos, "Blue Lagoon Drive in Brooklands. The whole of this street is red zoned land. Some of the homeowners are unhappy with the land zoning as they believe that their area has much less impact from liquefaction than other red zoned areas. Some of the street lights are leaning, but the road seems in very good condition for a red zoned street and there is little evidence of liquefaction. Most red zoned streets have none of their original surface left, and the liquefaction is evident on all the verges and gardens".
Dried liquefaction silt in North New Brighton. The photographer comments, "This is the result of liquefaction which spewed out after the double earthquake in Christchurch. Having flowed into a shallow depression that was deep enough for a fair quantity of the silty liquid to settle and separate: the heavy sand below and a talcum powder like substance on top. Some of these are so delicate that a mouse crossing them would probably crack them. Here the sun has dried them out and they have contracted and curled up towards their centres".
A photograph of liquefaction in the front yard of a residential property on Avonside Drive.
Flooding and liquefaction on the corner of Edward Avenue and Geraldine Street in St Albans.
Photograph captioned by Fairfax, "Volunteers help clean up liquefaction on Acland Avenue. Volunteer Ewart Ward".
Photograph captioned by Fairfax, "Volunteers help clean up liquefaction on Acland Avenue. Volunteer Tom Hutchison
Photograph captioned by Fairfax, "Volunteers help clean up liquefaction on Acland Avenue. Volunteer Tom Hutchison
A motorcycle embedded in liquefaction and floods that cover the road in a residential area.
Photograph captioned by Fairfax, "Volunteers help clean up liquefaction on Acland Avenue. Volunteer Ewart Ward".
A photograph of piles of liquefaction on the side of a residential street in Christchurch.
A motorcycle embedded in liquefaction and floods that cover the road in a residential area.
Residents shoveling silt in back yard that has been entirely covered in silt from liquefaction.
Liquefaction on the side of a road in Avonside after the September 4th earthquake.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
Build up of liquefaction that has seeped from the ground onto the road and footpath.
Residents shoveling silt in back yard that has been entirely covered in silt from liquefaction.
Liquefaction in a horse paddock. In the foreground cracks are visible in the road surface.
The road, driveway and footpath are covered in silt from liquefaction in a residential area.
Earthquake-triggered soil liquefaction caused extensive damage and heavy economic losses in Christchurch during the 2010-2011 Canterbury earthquakes. The most severe manifestations of liquefaction were associated with the presence of natural deposits of clean sands and silty sands of fluvial origin. However, liquefaction resistance of fines-containing sands is commonly inferred from empirical relationships based on clean sands (i.e. sands with less than 5% fines). Hence, existing evaluation methods have poor accuracy when applied to silty sands. The liquefaction behaviour of Christchurch fines-containing (silty) sands is investigated through a series of Direct Simple Shear (DSS) tests. This type of test better resembles earthquake loading conditions in soil deposits compared to cyclic triaxial tests. Soil specimens are reconstituted in the laboratory with the water sedimentation technique. This preparation method yields soil fabrics similar to those encountered in fluvial soil deposits, which are common in the Christchurch area. Test results provide preliminary indications on how void ratio, relative density, preparation method and fines content influence the cyclic liquefaction behaviour of sand-silt mixtures depending on the properties of host sand and silt.
People walking amongst silt in Hagley Park shortly after the 22 February 2011 earthquake. These silt deposits were caused by the soil liquefying during the 22 February 2011 earthquake. The water flowed out, bringing sand with it.
A photograph of detail of a damaged house. The photograph is captioned by BeckerFraserPhotos, "Seabreeze Close, Bexley".
A large crack in the ground at Sullivan Park in Avonside.
A large crack in the ground at Sullivan Park in Avonside.
A photograph of a road cone decorated with tinsel, captioned by BeckerFraserPhotos, "A view looking south along Bower Avenue in New Brighton".