19 Jul 11 19:38
-agreed as far as the probability goes, but the full live load has to be applied on both sides
-agreed, this type of formwork has the ability to resist forces from concrete placement [wall forms are tied with threaded rods, which take all the lateral wet concrete forces in tension]
-agreed, wind can blow only one way, so it will induce additional tension to only one anchor group, conservatively the total tension is applied to each opposing anchor group
-The failure cones do overlap. It turns out that it is a big deal to relocate these anchors.
I do not work for PERI, we are reviewing their comprehensive formwork calculations and drawings and we make sure that the anchors can take the applied forces by specifying the minimum concrete compressive strength needed for working, climbing, storm.
After talking to a statics department engineer in Germany, it turns out that he had done some tests on this situation a few years ago. The tests showed that the overlapping cones between the opposing anchor groups actually help in capacity because there is a good chunk of concrete in the cone intersection that is compressed. This test would be if both the opposing anchors are loaded at their max. I am awaiting his test results and the "theory" behind it as he told me.
Obviously if one of them is loaded, this is no different as having one anchor group.
Furthermore, the walls are reinforced. There is no question about the big capacity boost you get by the reinforcing steel, it basically makes the concrete so strong that the only failure mode becomes the steel shear/tension failure.
The individual anchor group is adequate to carry the max applied forces. So having the anchor groups closer together in opposite faces of wall, only helps their capacity. This would be my conclusion. I am interested to see his report.
Thanks for all your input!