Consolidation Rate

rate of consolidation

A slow infiltration occurs and the excessive pore pressures dissolve slowly, resulting in a consolidation settlement. consolidating The compaction rate can be monitored and the consolidation factor (cv) determined from the changes in density over a period of continuous loading. Captured changes in thicknesses during one of the loading steps in an odometer test are used to assess the consolidation cv. In this method, changes in thicknesses ( i.e.

settlements) are plotted against a proper timing algorithm [either Ötime or log(time)] and then the Tv:Ut theory graph is adjusted.

First part of the turn towards Ötime is about a line. This point's position is dependent on the arithmetic formula for the curvilinear section [See curves fit method: Terzaghi or Parametric Isochrones]. Therefore, the consolidation ratio is: Therefore, the consolidation ratio is: Therefore, the consolidation ratio is:

This is an alternate to the root-time approach, which is particularly useful when there is significant secondary compaction ("creep"). Uo point is localized by two points chosen on the graph for which periods (t) are 1:4, e.g. 1 minute and 4 minutes; or 2 minutes and 8 minutes; AP and PQ are the same vertically.

In the last part of the graph, the V100 point can be sufficiently flattened (i.e. no secondary-level compression). If significant secondary decompression is present, there may be significant crossover of line lines along the center and last sections of the graph by line100. Therefore, the consolidation ratio is:

Using the following fundamental equation: The deconsolidation of a 5th order claysheet. Consolidation factor for the load area is 0.955mm²/min. Estimate the amount of work involved in (a) 90% consolidation accounting, (b) 100 mm accounting. Layers of clays have a depth of 4.0 metres and drain both upwards and downwards.

Deconsolidation accounting was charged at 120mm. Make estimations of consolidation settings that can be anticipated after 1 year, 2 years, 5 years and 10 years of building. As a rule, the settling rate observations are higher than those obtained by the results of the odometer test. However, since the load is not often immediately imposed, the progressive use of the load should be taken into account.

Soil compaction in some cases (especially in newer soil ) will continue under permanent load after the total porosity overpressure has been removed, i.e. after completion of initial compaction - this is referred to as lateral compaction or crawling. You can approximate the r/log graph to a line whose gradient gives the factor of derived Ca (secondary compression).

Gradient of the lab graph is determined over a logging period, e.g. 1000 to 10000 minutes. This further compacts the ground so that it remains over-compacted in its uncontaminated state.

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