seismic design of reservoirs
seismic design of reservoirs
(OP)
Hi,
I'm designing a 0.5 MG reservoir in Seismic Zone 4 in California, and the geotech engineer has supplied us with three different design spectra graphs by 1) Campbell & Bozorgnia, 2) Boore, and 3) Sadigh. I've been instructed to use the most conservative of the three. Sadigh results in the most conservative zero period acceleration, but Boore results in more conservative freeboard and shear anchorage requirements.
In past projects, I see that our company has been given a graph containing the average of the three spectral graphs by the geotech engineer, and therefore used that.
Are there any clear requirements by AWWA, or is it up to us as engineers to make a judgement call? Can we just stick with the Sadigh graph to make it simple?
Thanks.
I'm designing a 0.5 MG reservoir in Seismic Zone 4 in California, and the geotech engineer has supplied us with three different design spectra graphs by 1) Campbell & Bozorgnia, 2) Boore, and 3) Sadigh. I've been instructed to use the most conservative of the three. Sadigh results in the most conservative zero period acceleration, but Boore results in more conservative freeboard and shear anchorage requirements.
In past projects, I see that our company has been given a graph containing the average of the three spectral graphs by the geotech engineer, and therefore used that.
Are there any clear requirements by AWWA, or is it up to us as engineers to make a judgement call? Can we just stick with the Sadigh graph to make it simple?
Thanks.





RE: seismic design of reservoirs
Your geotech could tell you "The allowable bearing is 5000 PSF. Or if I do it the other way, it's 3000 PSF. Or method 3 gives 1200 PSF. Take your pick." That's not really a reasonable answer, and sounds like an attempt to shift design responsibility from him to you.
Don't assume that the "most conservative" answer is the best, by the way. I have seen tanks with seismic design criteria that were just completely silly. It is not a good situation, and it is doubtful the owners really gained anything from the exercise.
RE: seismic design of reservoirs
RE: seismic design of reservoirs
1) Campbell & Bozorgnia, 2) Boore, and 3) Sadigh.....?