U.K. Case Study: Bluewater Retail and Leisure Destination Reinforced Soil Slopes to Form Steep-Sided New Lakes - Reinforced Soil Engineering: Advances in Research and Practice - page 136

therefore decided to incline the lining at an angle a of approximately 5 below the

reinforced soil block. (This equated to a fall of 1.5m from toe to heel over the
width of the block.)
The bottom reinforcement layer remained horizontal and was positioned a
minimum distance of 10 cm above the lining system at the face. This ensured that
the critical design interface frictional value would not reduce.
The factor of safety against sliding over the inclined geomembrane was
calculated by resolving forces about the geomembrane (Fig. 3).
Note: The net mobilizing force (P ) is assumed to act on an angle to the rear
of the reinforced soil wall

8

f ls . W

weight of the reinforced soil block,
and F and N are the frictional and normal forces acting on the inclined
geomembrane.
By resolving forces perpendicular to the geomembrane:

¼ A £ ¼

W cos I þ :sin ð 10 8 þ I Þ¼ N ð 1 Þ

By resolving forces parallel with the geomembrane:

F ¼ N tan 20 8 ð 2 Þ

F þ W sin a

FoS ¼ ð 3 Þ

P cos ð 10 8 þ a Þ

Figure 3 Force resolution on reinforced soil block.