Liquifaction is an important secondary hazard from earthquake. I would like to initiatate discussion on what is What is quick and ditry way for first level of estimating liquifaction potential of an area of the order of 200,000 square km ?
Hi Sushil,
You could use the presence near the surface (untill about 4 m depth) of sand below the water table and which is covered by a less permeable layer (clay, silt, concrete, ...). So by combining the presence of sand with presence of capping layer and presence of watertable near the surface. The liquefaction potential of sand also depends on its grain-size distribution and amount of compaction.
Slopes may worsen the effect of liquefaction on buildings. You need earthquakes or other vibrations with sufficient lengths (number of cycles) to intiate liquefaction.
Hopefully this may help your work,
Greetings,
Koen
Similar to Koen Verbeek's suggestion, I would suggest using the age and composition of the surface geologic units combined with the depth to the water table. See Journal of the Geotechnical Engineering Division GT4, April 1978, Mapping Liquefaction-Induced Ground Failure Potential by T.L. Youd and D. M. Perkins. If you are interested, I could provide a more extensive bibliography of work based on the Youd and Perkins publication.
One can do pretty well just based on the descriptions of the Neogene geology. If one has access to information about the depth to the water table and even a few SPT values for the geologic units, then one can do quite well.
Dear Mathew, Coeln,
Thanks for prompt response.'
Dear Mathew, please provide some more details. Regarding approach mentioned in your response (2nd paragraph), could you please share an example or worksheet (xlsfile).
I discovered that the article I cited is posted to Research Gate. Here is the link: Article Mapping Liquefaction-Induced Ground Failure Potential
When you ask for "an example or worksheet (xls file)." Are you requesting a spreadsheet that implements the "Simplified Procedure" of Seed and Idriss? (downloadable here: https://ntrl.ntis.gov/NTRL/dashboard/searchResults/titleDetail/PB198009.xhtml
) If so, a would say that the calculations I was suggesting can easily be done by hand. My implementations of the Simplified Procedure are all buried in storage boxes because I am not actively doing liquefaction assessments on a scale that can't just be done by hand.
That said, the Youd and Perkins article suggests classifying Neogene geologic deposits simple based on their depositional environment. This based on typical liquefaction susceptibility of the various types of deposits. I was suggesting that a small number of SPT values for the geologic deposits in a specific area could be used to verify such generalizations. For this, hand calculations would serve just fine.
One can do just fine without the SPT and groundwater refinements that I referred to in the second paragraph. That would be the "quick and dirty" approach asked for in the question.
Unqualfied comments:
1- Susceptibility of the sediment volume of interest becoming less than the water it is holding or capable to hold in stable repose
2- Suscebtibility of sediment to undergo a change of repose at the cost of strength properties due to excess of water than that it holds or is capable of
3- Energization , either local or regional, of such nature and scale which can cause any of above e.g. changes of stress pattern, repetition of loading and changes of pattern thereof, or even that of temperature
4-Change of phsyical composition and grains size distribution of such nature over time to cause or result in similar to any of above
- Badges
- Science topic
- Similar topics
- Political Science
- International History and Politics
- Globalization