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Earth Quake Proofing your observatory

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#1 jgs99v

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Posted 13 September 2021 - 12:55 AM

Any experience in the planning or execution of an observatory - whereby factors or mitigation was designed in against earthquake damage.

I could not find any data on the Berkeley University site or the USGS

 

TIA



#2 macdonjh

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Posted 13 September 2021 - 10:31 AM

Not something I had to consider here.  There will be quite a bit of mass sitting on the top of your pier, so foundation design as well as any connections between pier components (e.g. concrete footer and metal pier) and between the pier and your mount should be suitable designed.  You can get seismic design factors here: https://hazards.atcouncil.org/

 

These will provide you with the lateral accelerations to use in designing your foundation and connections.  I am not a civil/structural engineer, so I can't provide any tutorial about using the information from the ATC website.  However, once you have the lateral accelerations, you can determine the forces generated by your mount and scope being shaken by and earthquake (F=m*a), which is the shear force your connections have to withstand.  With that information you can also figure out your overturning moment (M = F* pier height), which is proportional to the tensile force your pier connections have to resist.

 

Good luck.



#3 jgs99v

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Posted 15 September 2021 - 03:10 AM

MacDonJh - Way kool.  Although beta - it's really nice how the front end sets the specifics.

I need to dig out my geo report.

 

Thanks!!!!



#4 macdonjh

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Posted 15 September 2021 - 01:02 PM

No worries.  That's the site the civil engineers in our office go to for site data when starting a project.  The local building inspector's office, or an architect, should have the data for your location as well.




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