msquared48
Structural
- Aug 7, 2007
- 14,745
I have some construction drawings of an existing steel water tank - 60'-8" in diameter - with a domed roof with a 56' radius - apparently all the information available from the local water district. Other than the 8mm (.299") plate for the roof structure, there appears to be no stiffeners used in the roof structure, other than an 1.5" welded lap splice of the triangular roof segments.
From anyone's professional experience with water tanks, is this normal construction for the roof of a water tank with no apparent central column, and using three-dimensional plate theory (snap-through analysis) with a tension tie at the edge?
The intent of the client is to mount eight cell antennas in two sectors on a low space frame on the top, and I am nervous about that - probably no more than 500# total weight. Snow load alone would be about 72K @ 25 psf. I could invoke the no more than 1% live load increase rule of the industry and let it go, but would be happier with more structure here to begin with.
I think that I am going to push the water district for more original structural design information here at the least...
Mike McCann
MMC Engineering
From anyone's professional experience with water tanks, is this normal construction for the roof of a water tank with no apparent central column, and using three-dimensional plate theory (snap-through analysis) with a tension tie at the edge?
The intent of the client is to mount eight cell antennas in two sectors on a low space frame on the top, and I am nervous about that - probably no more than 500# total weight. Snow load alone would be about 72K @ 25 psf. I could invoke the no more than 1% live load increase rule of the industry and let it go, but would be happier with more structure here to begin with.
I think that I am going to push the water district for more original structural design information here at the least...
Mike McCann
MMC Engineering