Determination

Of

Liquid limit(Cone penetration test)

Objective

Student should be able to:-

determine the liquid limit samples of soil by using cone penetration method

Theory

These experiments include the determination of moisture content where a soil changes from plastic to form a liquid

The liquid limit is defined as soil moisture content which will begin to flow with its own weight.

With cone penetration testing, the liquid limit is determined as the moisture content of the penetration value of 20 mm

The Atterberg limits can be used to distinguish between silt and clay, and it can distinguish between different types of silts and clays. These limits were created by Albert Atterberg, a Swedish chemist. They were later refined by Arthur Casagrande. These distinctions in soil are used in picking the soils to build structures on top. Soils when wet retain water and expand in volume. The amount of expansion is related to the ability of the soil to take in water and its structural make up (the type of atoms present). These tests are mainly used on clay or silty soils since these are the soils that expand and shrink due to moisture content. Clays and silts react with the water and thus change sizes and have varying shear strengths. Thus these tests are used widely in the preliminary stages of building any structure to insure that the soil will have the correct amount of shear strength and not too much change in volume as it expands and shrinks with different moisture contents.

average transparency= first transparencysecond transparency

Mass of water Moisture content = --------------------

Total weight of Solid mass

or

Moisture content=(Canweight+wet soil)−(Canweight+dry soil)

(Canweight+dry soil)−(Canweight)

Mass of water

Soil sample

Moisture content % = --------------------x 100

Total weight of Solid mass

Apparatus

Metal container 55mm diameter and

40mm in

Spatula

Porcelain bowl

Distilled water

Can

Tray

Cone penetration

British standard sieve (0.425)

Pan Balance – sensitive to 0.1 gram

Procedure

PICTURE DESCRIPTION

200 grams ofsoil transparent0425 mm sieve prepared

Soil samples included in the porcelain bowl and mixed with distilled water until thick

Mixed soil sample added to a vessel with a spatula and compressed so that no air is trapped. The top is flattened with a spatula

Adjust the position so as to affect land in the ground. Cone is released for 5 seconds and locked the cone motion and a second gauge is taken. Cones cleaned and repeat this step until the difference is less than 0.5mm

About 10 gram sample is taken and stored into the tin and dried for 24 h and the weight is taken Repeat this process 4 times with the same soil samples of distilled water is added to the range of cone penetration is in the range of 15-25 mm

.

DATA AND ANALYSIS

No of test 1 2 3 4First

transparency

16.1 16.2 19.7 32.2

Secondtranspare

ncy

16.3 16.8 19.9 31.7

The average

transparency

16.2 16.5 19.8 31.95

No of can 1 2 3 4Can

weight0.050 0.051 0.048 0.053

Can weight + wet soil

0.064 0.063 0.069 0.069

Can weight

0.062 0.061 0.064 0.064

+dry soilmoisture content

0.167 0.2 0.313 0.46

moisture content %

16.7 20 31.3 46

average transparency= first transparency+second transparency2

Example:

16.1+16.32 = 16.2

Moisture content=(Canweight+wet soil)−(Canweight+dry soil)

(Canweight+dry soil)−(Canweight)

Example:

(0.064−0.062)(0.062−0.050) = 0.167

Mass of water

Moisture content % = --------------------x 100

Total weight of Solid mass

Example:

(0.064−0.062)(0.062−0.050)

= 0.167 =0.167 x 100=16.7 %

Discussion

From the graph: -

Liquid limit is: 26 %

While conducting the experiment, make sure the soil sample does not contain wood or stone. Make sure the soil is mixed evenly. It is an issue when the additions of distilled water as it slowly seep into the observed ground. This situation effects of the cone penetration reading. The higher reading is taken from the original soil with high moisture. Directly, proportional of organic content with liquid limit where, the higher the organic content the higher the liquid limit values of the soil sample.

Cone Penetration Test (CPT) is a simple test and versatile in which it is more popular in Malaysia and for soft clays and fine to

medium sand. It can be used as a direct method to obtain the bearing capacity for foundation design. Analysis is performed of the CPT data from the local site based on the relationship issue. Data categorized into sticky and not cohesion. Based on the results obtained, it is seen that the relationship of the issue now is not suitable. EquationMeyerhof bearing capacity and Schmertmann used to obtain estimates of the bearing capacity. Values were then plotted into a graph and then for the best lines available. Two relationships will be evaluated anddisplayed. This derived relationship represents the cohesive andcohesionless soil. Of the two relationships, it can be concluded that the relationship Schmertmann give a higher value than the value of bearing capacity of thecalculated using Meyerhof relationship. However, please note that the lack of data prevents a better relationship developed. Onerelationship will be proposed in this study to predict the bearing capacity based on a given resistance. . Relationship issues are not suitable for estimating the bearing capacity of shallow foundation. To land under reviewrelation to the bearing capacity of cohesive soils and cohesionless not Schmertmann as suggested by the prior estimate of the value of the actual bearing capacity. This relationship is no longer suitable for use.

Conclusion

Fine-grained soils such as clay and silt soil plasticity characteristics associated with water content. At very low water content, the soil is solid and when the water content is high, then the land would be liquid. Land changes from solid to liquid depend on water content and this

phase is called the shrinkage limit, plastic limit and liquid limit.

Cone penetration test is only a test done to determine the liquid limit. Many other methods that can be used to perform tests such as Casagrande liquid limit and others.

Reference

1. Donald Mcglinchey, , Characterisation of bulk solids, 2005, CRC Press DT Afrika.

2. Mazlan Mohammad Abdul Hamid, Standard aggregate sieve analysis TEST, ASTM International - Standards Worldwide, (July 2008) ASTM C136-06, retrived from http://www.astm.org/

3. Norliza Muhammad, concrete laboratory,(2006). Gradation Test. (2007), Norliza Muhammad,Fajar BaktiSdn. Bhd.

Content

no Title page

1 Objective 3

2 Theory 4

3 Equipment 6

4 Procedure 8

5 Data and analysis 10

6 Discussion 12

7 Conclusion 13

8 Reference 14