Soil Nail Wall Expansion Joints

[72shortbox]

Does anyone have any input on what the spacing should be on expansion joints for a soil nail wall with a cast in place face? I had a comment from a reviewer suggesting putting a joint at every row of nails, but I thought that was exessive and could actualy reduce the effetiveness of the face.

 

[PEinc]

For anchored walls (tiedback and soil nailed) with permanent concrete facings, I try to follow AASHTO which requires vertical contraction joints at 30 feet on center and vertical expansion joints at 90 feet on center. I adjust this spacing as required to assure that these vertical joints fall directly between two soldier beams or soil nails. If the soldier beam or soil nail spacings are not multiples of 30 feet, I try to make my joint spacing as close as possible to 30 feet. In contraction and expansion joints, the resteel does not run through the joints (or else the joint will not expand or contract).