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 Subject : Design requirements for lateral spreading - new code.. 09/12/2019 09:33:18 AM 
Kelly Cabal
Posts: 26
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This question was posed by a CalGeo member:

I am looking to find out if there are members or resources available that can help with pile design for lateral spreading. I am finding that the lateral loads are so high in the crust (passive pressure times 3), the piers are cost prohibitive for single family homes. In the past, we have used mat slabs, but the new code is going to require piles. Any help or guidance is appreciated.
 Subject : Re:Design requirements for lateral spreading - new code.. 09/12/2019 09:59:46 AM 
Doug Schwarm
Posts: 2
Location
Kelly - You ask an excellent question. Be sure that first you're taking advantage of the 12" allowance in ASCE 7-16 Table 12.13-2. (And yes, it's not yet the official CA code, but building department generally allow using the updated guidance). Then, detail for ductility according to 12.13.9.3.4.

If the "tolerable displacement" approach is unacceptable (you're designing a hazardous waste facility or a Microsoft Millionaire's house, for example) then consider the Caltrans approach in Memo to Designers 20-15. The Caltrans website has been wonly for some time now, so here's links to the manuals in our technical library.

https://www.dropbox.com/s/cd96lzbswfrvf2d/Caltrans%20MTD%2020-15%20Lateral%20Spreading%202008.pdf?dl=0

and

https://www.dropbox.com/s/cu97db2j0d5dm20/Caltrans%20MTD%2020-15%20Lateral%20Spreading%202008%20Att%201.pdf?dl=0

This approach is being updated but the guidance is not yet published.

Hope this helps,
Doug
 Subject : Re:Design requirements for lateral spreading - new code.. 09/12/2019 10:07:07 AM 
Yvette Wilson
Posts: 1
Location
Doug-Thank you for your reply and the link to the references.
 Subject : Re:Design requirements for lateral spreading - new code.. 09/12/2019 10:26:26 AM 
Robert Pyke
Posts: 3
Location
At least part of the problem is that many estimates of lateral spreading displacements (and of the occurrence of liquefaction and the magnitude of earthquake-induced settlements) are excessively conservative. See the expanded version of the presentation that I gave recently at the 2nd Ishihara Colloquium, sponsored by EERI and held at San Diego State University last month:

https://www.linkedin.com/pulse/improved-analysis-potential-lateral-spread-earthquakes-robert-pyke
 
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