Here's the x-section. As you can see these are small walls and that is why we're so surprised the reviewer has made such an issue of this project.
http://files.engineering.com/getfile.aspx?folder=a0afaf47-095f-414d-9beb-5f03253f6479&file=hghgei_sbcglobal_net_20110815_140421.pdf
THanks to both Hokie66 & RFreund-- Indeed there is a wrinkle. The problem is to determine the amount of passive pressure from the upper wall that is to be applied to the lower wall. We've tried several approaches but all have been rejected by the S.E. revier for the state agency involved. One...