Bihar Institute of Hydraulic and Allied Research, Khagaul, Patna,
Porosimeter has been described in this paper to provide a correct and fairly reliable data for determination of Density and Moisture Content of Soil in compacted fill in order to compute the compaction efficiency. The apparatus is very simple consisting of two metallic chambers connected and air-tight by a Screw, a Manometer and a Pressure Bulb. It has been designed for use in the field also with slight modifications.
The following mathematical relationships have been established in connection with the use of ‘Porosimeter’ :—
1. K/Dw 1/G = X/100 (1 - K/Dw) + 1/10?m+m(X-Xo)
Where
K = density of water
Dw = wel density of soil
G = specific gravity
m = constant
X = moisture percentage
Xo = optimum moisture content.
2. K/Dm - 1/G Xo/100 + 1/10?m
Where
Dm = Proctor’s M.D.D.
Xo = optimum moisture content
G = specific gravity
m = constant.
V1/W1 - 1/G
3. P = - × 100
1 - V1/W1
Where
p = - moisture percentage
V1 = volume of wet soil
G = specific gravity
W1 = weight of wet soil.
Moisture control is considered very essential in the construction of earth dams and it is a key to the effective use of compaction equil,ment in all earthen embankments. Most of.the methods for moisture determination are time consuming and the equpments required in some cases are either costly or cannot be conveniently ued in the field. ‘Porosimeter’, a single appwratus introduced in this paper provides moisture control information and wet density in the shortest possible time.
