Fill material properties
(1) The lower the soil friction angle, the higher the internal earth pressure
restrained by the wall.
(2) The lower the soil friction angle, the lower the apparent friction coefficient
for frictional reinforcing systems.
(3) The higher the plasticity of the backfill, the greater the possibility of creep
deformation, especially when the backfill is wet.
(4) The greater the percentage of fines in the backfill, the poorer the drainage
and more severe the potential problem from high water pressure.
(5) The more fine-grained and plastic the fill, the more potential there is for
corrosion of metallic reinforcement. Fill retention versus cut retention
(1) Fill retention (bottom-to-top construction)
(a) Earth walls (extensible and inextensible tensile reinforcements)
(b) All semigravity walls
(c) Modular walls, generic walls, and mass concrete walls