.
( ) top embankment ( ) 5 5 top embankment 0.31 0.24 & 0.21 top emb 11 11.5 = 11.25
A=W/4{LT+2Q+RT}
A=
W=
LT=
Q=
RT =
= A1+A2}/2*D

D = 25
1.25