What is the meaning of over consolidation?

noun. Consolidation to an excessive degree; specifically the consolidation of soil to a greater degree than could have been produced by the present pressure of overburden.

How do you calculate over consolidation ratio?

The OCR can be computed by the following equation:(8) OCR = 2 1 1.95 M + 1 q t – u 2 σ v 0 ′ 1 / Λ where M is the slope of the critical state line in a p′–q plot (where p′ is the mean effective stress and q is the deviator stress) defined as, M = 6 sin ϕ ′ 3 – sin ϕ ′ . In Eq.

What does it mean if a soil is Overconsolidated?

If the current effective stress is less than the preconsolidation stress, then the soil is said to be over-consolidated (OC). This can be due to shrinking and swelling of the soil on drying and rewetting, changes in ground water levels, and unloading due to erosion of overlying strata.

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.

What causes over consolidation?

Overconsolidation can occur in clays due to reasons such as; Self-weight of the soil which has eroded. Weight of continental ice sheet which has melted. Desiccation of layers close to the surface.

How do you measure Preconsolidation pressure?

Preconsolidation pressure cannot be measured directly, but can be estimated using a number of different strategies. Samples taken from the field are subjected to a variety of tests, like the constant rate of strain test (CRS) or the incremental loading test (IL).

What is the purpose of consolidation test?

Consolidation test is used to determine the rate and magnitude of soil consolidation when the soil is restrained laterally and loaded axially. The Consolidation test is also referred to as Standard Oedometer test or One-dimensional compression test.

What is over consolidated clay?

over-consolidated clay Clay that has been more compacted than would be expected from the existing overburden, e.g. it has been subjected to pressure from overburden that has subsequently been removed by erosion. Compare NORMALLY CONSOLIDATED CLAY.

What is normally consolidated clay and over consolidated clay?

What are the causes of over consolidation? Normally consolidated clays are these that are currently experiencing the maximum vertical overburden effective pressure they have ever experienced in their history. Over consolidated clays have experienced a higher overburden stress in the past.

What are the types of consolidation?

There are different types of business consolidation, including statutory consolidation, statutory mergers, stock acquisitions, and variable interest entities. Consolidation can lead to a concentration of market share and a bigger customer base.