Theory
Unit weight is the weight of soil per unit volume is called unit
weight or density. It includes the whole soil mass, the solid particles plus
all voids with or without moisture. It depends upon saturation ‘S’. since the
dry unit weight of solids per unit of total volume of a soil mass is called dry
unit weight.
Volume = Ws/v gm/c.c.
Application
Therefore density of soil deflects most of the properties of soil.
Density of soil in place is compacted soil and used as quality control measured
of earth work in embankment in place soil density of natural soil helps to
determine bearing capacity, calculation of settlement as well as for stability
analysis of natural slops.
Item required
1. Cylindrical core cutter of steel 127.4 mm long and 100 mm in
width a metal thickness of 3 mm at one end.
2. Steel trolley 2.5 cm high and 10 cm internal diameter with
wall thickness 7.5 mm.
3. Steel hammer.
4. Steel rule.
5. Straight edge.
6. Balance.
7. Container.
Diagram
Core cutter
Procedure
1. The inside dimension of core cutter was measured accurately
to 0.25 mm and calculated its volume.
2. The mass of the core cutter without trolley was measured
accurately.
3. Exposed the small area about 30 sq.cm for test levelled that
surface put the trolley on the top of the core cutter and drived the assembly
into the soil with the help of hammer with the top of the dolly about 1 ½ cm
above surface.
4. Dry weight the container from the surrounding soil and
allowed some soil to project from the lower and of the cutter with the help of
straight edge.
5. The mass of cutter face of soil was measured.
6. Kept some sample of soil for water content determination in
the oven.
7. Repeat the test of the three location neat by end get the
average density.
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OBS.
NO.
|
DETERMINATION
NO.
|
DETERMINATION
|
|
|
1ST READING
|
2ND READING
|
||
|
01
|
Mass of
core cutter wet soil (gm)
|
2645 gm
|
2580 gm
|
|
02
|
Mass of
core cutter (gm)
|
930 gm
|
970 gm
|
|
03
|
Mass of
wet soil
|
1715 gm
|
1670 gm
|
|
04
|
Volume
of core cutter (MR)
|
1021.0
cm3
|
1021.0
cm3
|
|
05
|
Bulk
density P = ¾ g/cm3
|
1.68
kg/m3
|
1.58
g/cm2
|
|
06
|
Bulk
unit weight Y = 9.81 P
|
16.48
kg/m3
|
15.5
kg/m3
|
|
07
|
Container
no.
|
A
|
B
|
|
08
|
Mass of
contain + wet soil
|
66 gm
|
37.3 gm
|
|
09
|
Mass of
contain + dry soil
|
58 gm
|
34.5 gm
|
|
10
|
Mass of
container
|
23 gm
|
23 gm
|
|
11
|
Mass of
dry soil
|
35 gm
|
11.5 gm
|
|
12
|
Mass of
water
|
2.89 gm
|
2.89 gm
|
|
13
|
Water
contain
|
22.66 %
|
24.35 %
|
|
14
|
Dry
density Pd =p/1+w gm/cm3
|
1.37
gm/m3
|
1.28
gm/m3
|
|
15
|
Dry
unit wt. Yd = Y/1+w kg/m3
|
13.41
kg/m3
|
12.46
kg/m3
|
RESULTS
1. Percentage of water
content = 24.35 %
2. Dry density of soil
sample = 1.28 gm/cm3
3. Dry weight of soil
sample = 12.46 kg/m3
