A B C D E F G H I J K L M N O P Q R S T U V W X Y

U

ultimate bearing capacity
undrained loading
undrained modulus (Eu)
undrained shear strength (su)
unit weight (g)
unit weight of water (gw)

ultimate bearing capacity

The bearing stress which would cause shear failure in the soil below a foundation; dependent upon the shear strength of the soil and on the shape and depth of the foundation.

undrained loading

Loading which is applied so quickly that there is no time for any drainage of pore water and so there is no change in volume; pore pressures may change and lead to subsequent seepage and consolidation.

undrained modulus (Eu)

The ratio of the change in total axial stress and the change in axial strain under undrained loading.

undrained shear strength (su)

(Also undrained strength) The shear strength of a saturated soil at a given water content (or voids ratio, or specific volume) under loading conditions where no drainage of porewater can take place. The undrained shear strength of soil is independent of applied stresses and therefore can be measured at any level of stress, provided the void ratio remains constant. The undrained Mohr-Coulomb envelope will be horizontal (fu = 0).

unit weight (g)



The weight per unit volume of a soil. Units: kN/m³
Ws = weight of solid grains
Ww = weight of water
V = total volume

unit weight of water (gw)

The weight of a unit volume of water;
gw = 9.81 kN/m³.