Unit Cell Testing of Reinforced Soils - Reinforced Soil Engineering: Advances in Research and Practice - page 57

Figure 12 Arrangement of reinforcement in shear box; (b) shear stress-strain

relationships. (From Ingold, 1981.)

The vertical and horizontal forces due to N reinforcement would be

T v ¼ 2Nac u Lb sin u ð 36 Þ

T h ¼ 2Nac u Lb cos u ð 37 Þ

Assuming that the increment in undrained shear strength by reinforcement,
Dc u , is due to the horizontal force, the adhesion factor is determined as

Dc u A
2Nc u Lb cos u

a ¼ ð 38 Þ

where A is the area of the shear box.