# Relationship between relative compaction and density

Because of the many similarities, the terms relative compaction and relative between terms and to illustrate a simple and practical correlation between them. maximum dry density in relation to moisture content was obtained. Relative compaction (CR) of soil at each location was then calculated to the soil compaction. I am now being told that I need to determine the relative compaction of the To run a proper moisture-density relationship in the lab (ASTM.

### Relative Density and Relative Compaction

One needs to understand the context and engineering definitions - not the common vernacular - similar to the arguments I have made with allowable bearing capacity based on shear and allowable bearing pressure based on serviceability. I think it a bit disingenuous of the person asking the OP to estimate the relative compaction from the N values.

The N values are reflective of many things such as angularity of the particles, particle size vs the spoon's diameter and the like and this doesn't always translate to a general correlation. The question is whether this is to show that there was no control on the fill being placed a contractual thing or the desire to build on the land an engineering thing. This would indicate uncontrolled fill.

CEEN 341 - Lecture 6 - Soil Compaction

If for the engineering, one would look at it in the sense of any soils investigation and apply design principals accordingly fully aware, though, of the large variations that are likely but not necessarily inherent in an uncontrolled fill. First I agree that the California sampler i. While you can get a density, it will be somewhat approximate. Further what maximum dry density will you use for comparison - some surface-obtained bulk sample?

Likley to be just another approximation.

Let's say you use all these approximations and "calculate" some value like 92 percent relative compaction. I mean would that mean you can't build on the stuff? Would that mean you'd have to use piles?

## Definition of relative compaction

I don't tell you that as some glib response. I tell you this 'cause that's what I'd do and have done in the past. After all, the relative compaction is moot if you can show some measure of subbase improvement in conjunction with the in-situ properties of the fill are such that the structural loads and foundations can function for the intended development. It is not perfectly accurate but what is?

In this research, different tests were carried out such that sieve analysis, specific gravity, Standard, and Modified Proctor compaction tests. Also minimum and maximum void ratio, were tested using Egyptian specifications [2].

The test results are used to evaluate the different soil properties required for investigation of possible correlations between 1 them. The relationships between tested maximum and minimum void ratio, tested minimum void ratio and coefficient of uniformity, and tested and calculated minimum void ratio were studied. Then, correlation between degree of compaction, RC, and relative density.

### Relative Density vs Relative Compaction and in-situ testing - Soil testing engineering - Eng-Tips

Then, relationship between coefficient of uniformity and maximum dry density tested by using standard proctor tests and calculated using relative density. Twenty different sample of pure sand tested in this research were collected from different cities from Fayoum governorate as shown in table 1. From sieve analysis results, coefficient of uniformity Cu and coefficient of curvature Cc were calculated. All tested samples were classified as poorly graded sand according to ASTM [3] and having less than 12 percent fines.

Also minimum, emin ,and maximum void ratio, emax, were tested to calculate relative density, Dr. Other tests were carried out for all the samples such as, specific gravity, Standardand Modified Proctor compaction tests.

For sandy soil the relative density, Dr, expresses the degree of compactness with respect to both the loosest and 2 densest states achieved by slandered laboratory procedures. Most commonly, the relative density is expressed in terms of void ratio: Relative density, Dr, is a useful parameter for describing the relative behavior of cohesionless soils.

Increasing relative density, Dr, generally means increasing strength and decreasing compressibility.

If it is negative, a collapsible soil structure may be present, such as can occur with honeycombed soils and very loose cemented or calcareous sands with e0 is bigger than emax, Kulhawy, and Mayne [4 ].

Since it is very difficult to obtain truly undisturbed samples of clean soils, the direct measurement of Dr also is difficult. However, the three separate parameters, emax, emin, and e0 were be evaluated according to the specifications. Moreover, it is difficult to directly determine the in-place void ratio of clean sands and granular soils with depth because undisturbed sampling is generally not possible.

Correlation with Maximum and Minimum Void Ratio The relationship between, the minimum and maximum void states has been proposed as a straight line, its inclination being equal to the value 0. In recent study, following relation was obtained from tests results, and it is close to that obtained by Poulos [5] as shown in Fig. From tests results following equation were predicted, as maximum void ratio increase, the minimum void ratio increase for the same sample.

Following equation was estimated: Proctor Figure 2 Correlation between maximum dry densities calculated using relative density and a Modified Proctor and b Standard Proctor compaction test. As shown in Fig. That is because that minimum void ratio calculated using Modified Proctor test is close to that tested.

Correlation with Relative Compaction The compaction of soil in the fill is the most important part of the construction of an embankment particularly a high embankment as for an earth dam.

It is desirable to obtain a high density of the soil placed in a fill to reduce future settlements, percolation through the fill and to increase its shear resistance. Due to the obvious disconnect between the types of energy in the laboratory and the field, some method is needed to express the laboratory— measured compaction parameters, i.