Wednesday, September 26, 2007

Stepped versus Full Height Retaining Walls

Greetings,
 
A client is inquiring as to the relative merits of stepped versus full height retaining walls from the constructability stand point. I am considering a full height 8' gravity wall versus two, 4' walls, offset 5'. What I am not sure about are the osha excavation requirements. Does an excavation more than 4' need to be made at 45 deg.+/- from the base of the footing, heel side, sloping continuously to finished grade, or, can there be vertical cut, 4' max., at either the top or bottom of the sloped excavation?
 
Thanks,
 
Michel Blangy, P.E.