Void ratio is  defined as the ratio of volume of voids to the volume of solid particles i.e,

`e=V_v/V_s`

`or, e=(V_w+V_a)/V_s`

Porosity denoted by n, is defined as the ratio of volume of voids to the total volume of soil. It is expressed in percentage.i.e,

`n=V_v/V*100`

    `=(V_a+V_w)/(V_a+V_w+V_s)*100`

Degree of saturation denoted by $S_r$ is defined as the ratio of volume of water to the total volume of voids in the soil mass. It is expressed in percentage.i.e,

`S_r=V_w/V_v*100`

Water content or content of a soil mass, denoted by w, is defined as the ratio of weight of water to the weight of dry soil.i.e,

`w=W_w/W_s`

The weight used in the about expressions is the weight of water loss when the soil is heated to a temperature of 105 degree centigrade to 110 degree centigrade for such length of time that its weight is constant. In routing laboratory test, a period o....

Void ratio:

Void ratio is  defined as the ratio of volume of voids to the volume of solid particles i.e,

`e=V_v/V_s`

`or, e=(V_w+V_a)/V_s`

Porosity:

Porosity denoted by n, is defined as the ratio of volume of voids to the total volume of soil. It is expressed in percentage.i.e,

`n=V_v/V*100`

    `=(V_a+V_w)/(V_a+V_w+V_s)*100`

Degree of saturation:

Degree of saturation denoted by $S_r$ is defined as the ratio of volume of water to the total volume of voids in the soil mass. It is expressed in percentage.i.e,

`S_r=V_w/V_v*100`

Water content:

Water content or content of a soil mass, denoted by w, is defined as the ratio of weight of water to the weight of dry soil.i.e,

`w=W_w/W_s`

The weight used in the about expressions is the weight of water loss when the soil is heated to a temperature of 105 degree centigrade to 110 degree centigrade for such length of time that its weight is constant. In routing laboratory test, a period of 24 hours is considered enough for drying.

Bulk unit weight:

Bulk Unit Weight or mass unit weights denoted by `gamma_t` is defined as the weight of soil mass per unit volume of soil mass.i.e,

`gamma_t=W/V`

                  =`(W_s+W_w)/(V_s+V_w+V_a)`

Dry unit weight:

Dry Unit Weight denoted by `gamma_s` is defined as the ratio of weight of solid to volume of soil.i.e,

`gamma_s=W_s/V`

Unit weight of water:

It is the ratio of weight of water per unit volume of water.i.e,

`gamma_w=W_w/V_w`

Specific gravity of solids:

It is the ratio of Unit Weight of soil solid to Unit Weight of water at 4 degree centigrade.i.e,

`G=gamma_s/gamma_w`

   `=W_s/(V_s*gamma_w)`

Specific gravityof water:

It is defined as the ratio of Unit Weight of water at any temperature to Unit Weight of water at 4 degree centigrade.i.e,

`G_t=gamma_w/gamma_0`

Where,`gamma_0` is the Unit Weight of water at 4 degree centigrade.