Kevin,
I did a seismic retrofit of a dual barrel vault hangar of concrete, built before WW II. There were a series of arches founded on some large deadman footings about 30'x15'x15' deep. IIRC, there were about 12- 1-1/2"diameter tie-rods along each arch. They were about 4 ft below grade encased in sleeves, and placed in a gravel bed. I would think the soil conditions, and hence foundations, will dictate the horizontal restraint at each arch line. I think you should be able to use a similar detail. Otherwise, the tie beam option would be another suitable solution that should work with the facility usage. HTH.
David A. Topete, SE
From: Kevin Below [mailto:kbofoz@gmail.com]
Sent: Sunday, October 07, 2007 7:28 PM
To: seaint@seaint.org
Subject: Foundations for a 3-pinned arch stadium
For an indoor sports stadium with 200-ft span, I have seen several examples using huge curved glu-lam beam sections about 6 ft high, at about 30 ft spacing. These beams are assembled on-site into a 3-pinned arch configuration (a pin at each support, and a pin at mid-span.)
The horizontal reaction at the base pins is enormous, and exceeds the vertical reaction. For example, 470 kips horizontal, and 405 kips vertical. The horizontal reaction is provided mostly by passive soil reaction on the perimeter wall.
Is this good enough ? Any thoughts on that ?
Is the passive reaction going to allow movement before it mobilizes ? Enough to be noticeable ?
What about seismic effects on the soil behind the wall ? Will it cause the soil to move under the pressure from the arches ?
What about a tie-rod (it would need to be big) under the sports surface, tying the 2 sides together ?
Kevin
kbofoz