Geotechnical Engineering, Civil Engg, Bhimaji Dashrath Kanawade

1. Experiment No.: 06 (B) Date:
DETERMINATION OF FIELD DENSITYBY SAND REPLACEMENTMETHOD
Object & scope:
To determine field density of natural soil in-place by the sand replacement method.
Reference:
IS: 2720 (Part - 28) -1974
Theory:
This method is suitable for any type of soil deposit. In this method the volume of the soil removed from
the hole is determined by filling it with standard sand using Sand Pouring cylinder and hence this
method is called sand replacement method.
Equipment:
1) Sand pouring cylinder of about 3 liter capacity mounted above a pouring cone and separated by a
shutter cover plate.
2) Cylindrical calibrating container, 10cm internal diameter & 15cm internal depth, fitted with flange
approximately 5cm wide & about 5mm thick
3) Glass plate, about 45cm square & 1cm thick
4) Metal tray with a central circular hole of diameter equal to the diameter of the pouring cone
5) Tool for excavating hole
6) Balance accurate to 1gm
7) Container for water content determination
8) Clean, closely graded natural sand passing the 600-micron IS sieve & retained on the 300-micron IS
sieve.
Procedure:
(A)Determination of bulk density of sand
(1) Fill the clean, closely graded natural sand into sand pouring cylinder up to a height 1cm below the
top. Determine the total initial mass of the cylinder plus sand (m1). This total initial mass should be
maintained constant throughout the test.
(2) Place the sand pouring cylinder on a glass plate and open the shutter and allow the sand to fill the
cone. When there is movement of sand it indicates that the cone is completely filled with sand. Now
close the shutter and find the mass of the sand filling the cone. This procedure repeated three times
to find the average mass of sand filling the cone (m2).
(3)Place the sand pouring cylinder with its initial mass (m1) on calibrating container. Open the shutter
&allow the sand to run out. Close the valve when no further movement of sand is observed. Remove
the cylinder carefully and find its mass (m3). Find the mass of natural sand filling the calibration
container. Determine the volume of calibration container
(B) Determination of dry density of soil in-place
(4) Expose about 45 cm2 area of the soil to be tested & trim it down to level surface. Keep the tray on
the level surface & excavate a circular hole of approximately 10cm diameter & 15cm deep & collect
all the excavated soil in the tray. Find the mass (M) of the excavated soil.

2. (5) Remove the tray & place the sand pouring cylinder so that the base of the cylinder concentrically
covers the hole. The cylinder should have its constant mass (m1). Open the shutter & permit the sand
to run in to the hole. Close the shutter when no further movement of the sand is seen. Remove the
cylinder & determine its mass (m4). Find the mass and volume of sand filling the excavated hole.
Finally determine the field density of soil sample
(6) Keep a representative sample of the excavated soil for water content determination.
Observation Table:
Sr.
No.
Description Reading
A. Determination of bulk density of sand
1 Mass of sand + cylinder (before pouring) m1 (kg)
2 Mass of sand in cone m2 (kg)
3 Diameter of calibrating container d (m)
4 Height of calibrating container h (m)
5 Volume of calibrating container Vcc (m3)
6 Mass of sand + cylinder (after pouring) m3 (kg)
7 Mass of sand filling calibrating container M1= m1- m2 - m3 (kg)
8 Bulk density of sand ρs = M1/ Vcc (kg/ m3)
B. Bulk density & unit Weight of soil
9 Mass of wet soil from the hole M (kg)
10 Mass of sand + cylinder (after pouring in the hole) m4 (kg)
11 Mass of sand in the hole M2 = m1- m2- m4 (kg)
12 Bulk density of soil ρ = (M/M2)×ρs (kg/ m3)
13 Bulk unit weight of soil γ = 9.81× ρ (kN/ m3)
C. Water content determination
14 Mass of moisture container W1 (gm)
15 Mass of container + wet soil W2 (gm)
16 Mass of container + dry soil W3 ( gm)
17 Water content ω = (W2-W3) / (W3-W1) × 100 (%)
18 Dry density of soil ρd = ρ /1+ ω (kg/ m3)
19 Dry unit weight γ d = γ /1+ ω (kN/ m3)
Calculation:
Bulk density ρ = (M/M2) ×ρs
Dry density ρd = ρ /1+ω
Result:
Field bulk density, ρ =
Field dry density, ρd =

3. Fig. Sand Pouring Cylinder