INSITU DENSITY TESTS SOIL MECHANICS

SOIL MECHANICS LABORATORYDEPARTMENT OF CIVIL ENGINEERINGUNIVERSITY OF MORATUWASRI LANKA

DENSITY OF SOIL IN PLACE BY THE SAND CONE METHOD

1.

APPARATUS

1. The standard density apparatus consisting of jar and detachable appliance consisting of a cylindrical valve with an orifice 12.5 mm in diameter

PROCEDURE

SCOPE

This test method sets out the procedure for the determination for the insitu dry density of

compacted soils, gravels and crushed rock materials in earth works and pavement layers by the

sand replacement method using a sand pouring cone. This test is generally limited to materials

with a maximum particle size of 5cm.

2. Any clean, dry free-flowing uncemented sand.

3. Balance of 10 kg. capacity readable and accurate to 01g.

4. Drying oven.

5. Miscellaneous equipment such as small pick chisels or spoons for digging test hole.

6. Density base plate with a center flanged 16.5 mm diameter hole

6. Repeat the procedure described in steps (1) to (5) at lease twice.

5. Weigh the apparatus and water and determine the temperature of the water (W2).

(a). Determine the Volume of the Jar and Attachment up to and Including the Volume of the valve Orifice as Follows :-

1. Weigh the assembled apparatus and record (W1)

2. Place the apparatus upright and open the valve.

3. Fill the apparatus with water until it appears over the valve.

4. Close valve and remove excess water.

(b). Determine the Bulk Density of the Sand to be Used in the Field Test as Follows :-

1. Place the empty apparatus up right on a firm level surface close the valve and fill the funnel with

sand.

2. Open valve and keeping funnel at least half full of sand, fill the apparatus. Close valve sharply and

empty excess sand.

3. Weigh apparatus with sand (W 3) and determine the net weight of sand by subtracting the weight

of the apparatus.

(c). Determine the Weight of Sand Required to Fill the Funnel as Follows:-

1. Put sand in the apparatus and secure weight of apparatus and sand.

2. Seat the inverted apparatus on a clean, level, plane surface.

3. Open the valve and keep open until after the sand stops running.

4. Close the valve sharply, weigh the apparatus with remaining sand (W 4)and determine the loss of

sand. This loss represents the weight of sand required to fill the funnel.

5. Replace the sand removed in the funnel determination and close the valve.

(d). Determine the Density of the Soil in Place as Follows :-

1. Prepare the surface of the location to be tested so that it is a level plane.

2. Seat the inverted apparatus on the prepared plane surface over the special plate provided and mark

the outline of the hole.

3. Dig the test hole inside the mark being very careful to avoid disturbing the soil that will bound the

hole. Soils that the essentially granular require extreme care. Place all loosened soil in a container

being careful to avoid losing any material.

4. Seat the apparatus in the previously marked position, open the valve and after the sand has

stopped flowing, close the valve.

5. Weight the apparatus with remaining sand and determine the weight of sand used in the test (W5).

6. Weight the material that was removed from the test hole (W).

7. Mix the material thoroughly and secure and with a representative, sample for moisture

determination.

8. Dry and weigh the moisture sample.

9. Repeat step (1) to (8) at least twice.

Department of Civil EngineeringUniversity of Moratuwa

In Situ Density by Sand Cone Method

Client: Project:

Determination of Density of Sand

Mass of bottle (kg) 1.942

Mass of bottle filled with sand (kg) 9.700

Mass of bottle and sand after

inverting on a flat surface (kg) Mass of bottle and sand after

8.200

filling the hole (kg) 6.930

Volume of the bottle (cm3) 3975

Bulk Density of the Sand (kg/m3) 1951.70

Mass of soil and Pan (kg) 2.510

Mass of Pan (kg) 1.310

Mass of Soil (kg) 1.200

Volume of the hole (m3) 0.000651

Bulk Density of the soil in field (kg/m3)

1844.1

Moisture Content Determination

Can Number a b bb

Mass of wet soil + can (g) 78.50 77.50 80.30

Mass of Dry soil + can (g) 65.80 65.90 68.40

Mass of can (g) 10.50 10.60 10.50

Mass of moisture (g) 12.70 .11.60 11.90

Mass of Dry soil (g) 55.30 55.30 57.90

Moisture content % 22.97 20.98 20.55

Average moisture content % 21.5

Dry Density Determination

Dry Density of the soil in field (kg/m3) 1517.8

Maximum dry density (kg/m3) 1670.0

Relative Compaction % 88.1

CALCULATION

1. Insitu Density of Soil:-

2. The Water Content of the Soil and then the Dry Density of the Soil :-

Water content

Dry Density

DISCUSSION

Discuss the following in your report.

1. The Limitations of this Test.

2. Compare the Core Cutter with other Methods of Field Density Determinations

1.

w= Mw

Ms

γ sand = W2 – W1 in Kg / m3

V1

γ dry = γ bulk

(1+w)

Specimen Calculation

Bulk Density of the sand = 9.700 - 1.942 3975 X 10-6

= 1951.7 kg /m3

Mass of sand required to fill the funnel = 9.700 - 8.200 kg = 1.500 kg

Mass of sand required to fill the hole = 8.200 - 6.930 kg = 1.270 kg

Volume of the hole = 1.27 1951.7

= 6.507 X 10-4 m3

Mass of the soil = 2.510 - 1.310 = 1.20 kg

Bulk density of the soil = 1.200 6.507 X 10-4

= 1844.1 kg

Moisture content of the soil = 78.50 - 65.80 X 100 65.80 - 10.50

= 22.97 %

Find the average moisture content

Average moisture content = 21.50 %

Dry density in the field = 1844.1 1 + 0.2150 = 1517.8 kg/m3

DENSITY OF THE SOIL IN PLACE BY THE CORE CUTTER METHOD

SCOPE

This test method sets out the procedure for the determination for the insitu dry density of

compacted soils in earth works and pavement layers.

1. The standard density apparatus consisting of steel cylinder and detachable collar.

2. Balance of 10 kg. capacity readable and accurate to 01 g.

3. Drying oven.

4. Miscellaneous equipment such as rammer, straight edge, chisels for digging surrounding soil.

APPARATUS

PROCEDURE

Determine the Density of the Soil in Place as Follows:-

1. Weigh the core cutter (W1) and calculate the internal volume from its dimensions

(V).

2. Prepare the surface of the location to be tested

3. Place core cutter with the collar on top, on the prepared surface and drive into the

soil with a help of a hammer.

4. Dig the surrounding soil to take out the core cutter.

5. After leveling off at both ends of core cutter with a straight edge, weigh it (W2).

6. Remove the soil sample from the core cutter and mix material thoroughly and secure and

weigh a representative sample for moisture determination.

CALCULATION

1. Volume of the density apparatus:-

V1 = (W2 - W1)T in millimeters.

2. Insitu Density of the Soil (at least for two trails)

a) Volume of the test hole V = (Ws – W4) in m3

γsand

Bulk Density of the Soil :

= W in kg/m3 V

4. The Water Content of the Soil and then the Dry Density of the Soil

Water Content w = Mw

MS

Dry Density γdry= γbulk

(1 + w)

DISCUSSION

Discuss the following in your report.

1. The Limitations of this Test.

2. Compare the Sand Cone Methods of Field Density Determinations

3. Why is it important to measure the field density? Give examples

Specimen calculation

Department of Civil Engineering University of Moratuwa

In Situ Density by the Core Cutter Method Client: Project:

Determination of bulk density of the soil

Mass of soil and core cutter (kg) 2.975Mass of core cutter (kg) 0.995Mass of Soil (kg) 1.980Volume of the core cutter (cm3) 1000Bulk Density of the soil (kg/m3) 1980.0

Moisture Content Determination

Can Number a b bbWeight of wet soil + can (g) 78.50 77.50 80.30 Weight of Dry soil + can (g)g)

65.80 65.90 68.40 Weight of can (g) 10.50 10.60 10.50 Weight of moisture (g) 12.70 11.60 11.90 Weight of Dry soil (g) 55.30 55.30 57.90 Moisture content % 22.97 20.98 20.55 Average moisture content % 21.50

Dry Density Determination

Dry Density (kg/m3) 1629.6 Maximum dry density (kg/m3) 1670.0

Relative Compaction % 94.6

Mass of soil = 2.975 - 0.995= 1.980 kg

Volume of the core cutter = 1000 cm3

Bulk density of the soil = 1.9801000 X 10-6

= 1980.0 kg /m3

Moisture content of the soil = (78.50 - 65.80)X 100 (65.80 - 10.50) = 22.97 %

= 1629.6 kg/m3

Find the average moisture content

Average moisture content = 25.30 %

Dry density in the field = 1980.0 1 + 0.2150