ARMY TM 5-5420-212-10-1
MARINE CORPS TM 08676A-10/1-1
Figure 3-10 Site Profile-DS 1-12 Bay
k.
Slope check
(1)
Longitudinal: Ensure that the difference in elevation between the F and F’ (use elevation of FRB) pegs
does not exceed 1/loth of the total bridge length. If it does, either pack up under the bridge, dig out from under the end(s)
of the bridge, or find another centerline.
(2)
Transverse/cross: Ensure that the transverse slope on both banks does not exceed 1/10th of the bridge
width (4.0 m) for MLC 60 and below and 1/20th of the bridge width MLC 61 and over. No transverse slope is permitted for
MLC 100(W). If these figures are exceeded, either pack up under the bridge, dig out from under the end(s) of the bridge,
or find another centerline.
I.
Calculate H, G and C
Calculate the far bank height (H), ground (at tail of bridge) clearance (G), and water (at front of bridge) clearance
(C), for later comparison against N (nose lift), T (tail lift), and D (deflection). The values of N, H, T, and G are relative to a
baseline drawn through the FRB and RRB. C and D are relative to the FRB/F line drawn from the FRB to F peg.
H = Elev F + Elev RRB x (L - 0.5 m)
4.6m
G = Elev O - Elev RRB x R Distance
4.6m
C = Elev WL - Elev F x W Distance
(L - 0.5m)
3-29
