Can the Overconsolidation ratio be less than 1?
Can the Overconsolidation ratio be less than 1?
The overconsolidation ratio, OCR, is the ratio of σp to σ o, and nu- merically represents the state of consolidation: an OCR equal to 1 is a normally consolidated sediment, an OCR greater than 1 shows over- consolidation, and an OCR less than 1 shows underconsolidation.
How do you calculate OCR?
OCR is evaluated by the formula: OCR = σ’p / σ’yy. If OCR≤1, the soil is considered to be normally consolidated, when OCR> 1 – it is overconsolidated.
What does Overconsolidated soil mean?
Overconsolidated soil may be defined as. “If the initial vertical effective stress of the soil sample is less than the preconsolidation stress, then the vertical effective stress in the field was once higher than its current magnitude, and the soil is called overconsolidated.”
How to calculate The overconsolidation ratio in soil?
5.3.4 Overconsolidation ratio The overconsolidation ratio (OCR) allows characterising the stress history of soils. This parameter can be computed from the preconsolidation stress, σ′ p, and the overburden vertical effective stress for a given soil, σ′ z, as (5.2)OCR = σ ′ p σ ′ z
What is the concept of over consolidation ratio?
In soils mechanics, the over consolidation ratio (OCR) is the relation between the preconsolidation pressure and the current effective stress of the soil. If OCR=1 the soil is normally consolidated (NC), if OCR>1 the soil is over consolidated (OC).
Is it good for soil to be overconsolidated?
Aging effects. From the term over consolidation it seems that there is an excessive consolidation in the soil. But that is not the case actually. Overconsolidation is almost always a good thing.
Which is the highest level of soil consolidation?
The highest stress that it has been subjected to is termed the ” preconsolidation stress “. The “over-consolidation ratio” (OCR) is defined as the highest stress experienced divided by the current stress. A soil that is currently experiencing its highest stress is said to be “normally consolidated” and has an OCR of one.