O
one-dimensional compression
one-dimensional modulus (E'o, M)
open layer
optimum water content (wopt)
overburden stress (svo s'vo)
overconsolidated soil
overconsolidation ratio (Rm Rmp Ro Rp)
one-dimensional compression
Compression taking place with zero radial and horizontal strain.
one-dimensional modulus (E'o , M)
The ratio of the change in vertical effective stress to the change in vertical strain, when there is zero horizontal strain.
E´o (or M) = ds´a / dea
E´o = 1 / mv
open layer
A layer or stratum of soil from which porewater may drain both upward and downward into overlying and underlying permeable layers, thus enabling two-way drainage; drainage path length = half the layer thickness.
optimum water content (wopt)
The water content at which the maximum compacted dry density can obtained.
overburden stress (svo, s'vo)
(Also overburden pressure) The stress on a horizontal plane at a given depth due to the weight of overlying soil or rock.
overconsolidated soil
Soil having a current state which lies inside the normal compression line:
· current normal effective stress is less than current yield stress
· overconsolidation ratio Ro > 1
· generally: "current stress is less than maximum stress in the past"
overconsolidation ratio (Rm, Rmp, Ro, Rp)
The ratio of maximum past effective stress to the current effective stress.
Rm = s´m / s´A
Ro = s´y / s´A
Rmp = p´m / p´A
Rp = p´y / p´A
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