Derive PWP on failure plane of active wedge behind retaining structure

[sadmoe]

Hello all,

I'm looking for some help regarding the following issue - any advice would be greatly appreciated.

I am trying to express U (the integral of u on the slip plane) in terms of W (weight of wedge), theta and r_u (pore pressure ratio)- for now, assuming beta=0 and alpha=90 (see attachment). I have spent a long time attempting this, but believe it is time I asked for help.

W, theta and r_u are all knowns.

Thanks in advance,

Moe