Quantification and Evaluation of the Liquefaction-Induced Flooding From the Christchurch Earthquake Sequence


Abstract eng:
Large areas in Christchurch, New Zealand and surrounding region were inundated multiple times as a result of earthquakeinduced liquefaction initiated by the main events of the 2010-2011 Canterbury earthquake sequence. This study documents information collected for numerous flooded areas, including estimated flood depths where possible. The ejected water volume due to liquefaction is estimated for six cases from the post-earthquake topographic data. The volume change due to the liquefaction settlement is calculated from the ground surface pre- and post-earthquake digital elevation model based on LiDAR data. The estimated liquefaction induced settlement agrees very well with observed inundation depths, confirming expectations based on liquefaction being a constant volume process. In addition to liquefaction ejecta, there are other potential sources of the observed flood waters, including damage to potable, sanitary sewer, and storm drainage infrastructure allowing the water to leak onto the ground surface. In some locations these damaged infrastructures clearly contributed to the inundation, but evidence indicates these alternate sources provided relatively small volumes of the total documented flood waters. As a result, this study confirms the observed flooding resulted mainly from liquefaction ejecta. This finding is important because for the first time it documents the previously relatively unrecognized liquefaction-induced flooding hazard which needs to be considered in urban and land development planning.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 543.:
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