Lab Reports on Determination of field density of soil by core cutter method.

 

TITLE: DETRRMINATION OF FIELD                          DENSITY OF SOIL BY CORE                                CUTTER  METHOD

     OBJECTIVE:

• To Determine the field density of soil by core cutter method

APPARATUS REQUIRED:

• Cylindrical core cutter
• Steel rammer
• Steel dolly
• Balance
• Steel rule
• Spade or pickaxe
• Straight edge
• Knife     

           

     

THEORY:

Core cutter method is the most used field method to determine the wet density of soil in the field. it is mostly used in an area with mostly the cohesive soils. Thus , it has limitations with the cohesionless soil. it is very fast and easy method for finding the field density of soil in the field than the other method.  Core cutter method of determining the field density of soil is only suitable for fine grained soil (Silts and clay). This is because collection of undisturbed soil sample from a coarse grained soil is difficult and hence the field properties, including unit weight, cannot be maintained in a core sample.

PROCEDURE:

• First of all,

the height (h) and internal diameter (d) of the core cutter was measured and grease was applied to the inside of the core cutter. 

• The Weight of the empty core cutter (W₁), was measured.
• Clean and level the place where density is to be determined.
• Drive the core cutter, with a steel dolly on its top, into the soil to its full depth with the help of a steel rammer.

• Excavate the soil around the cutter with a crow bar and gently lift the cutter without disturbing the soil in it.

• Trim the top and bottom surfaces of the sample and clean the outside surface of the cutter.

• Weigh the core cutter with soil (W₂)

• Remove the soil from the core cutter, using a sample ejector and take representative soil sample from it to determine the moisture content.

• Then, wet density of soil was calculated by using following relationships:  Ywet=(W2-W1)/V

   

OBSERVATIONS AND CALCULATIONS:

1. Empty Weight of core cutter (M1)=981 gm
2. Weight of core cutter+ soil (M2)=2833 gm
3. Height of core cutter (H)=13 cm
4. Internal Diameter of core cutter (d)=10 cm
5. volume of core cutter (V)=pi/4*D^2*H=1021.02 cc

    Then, field density of soil (P)=(M2-M1)/V

        (2833-981)/1021.02=1.814 gm/cc

RESULT:

From the above field procedure ,we have calculated the field density of soil as P=1.814 gm/cc

CONCLUSION:

Hence, by this way we can compute the field density of soil . which differ place to place depends upon the soil composition, natural water content, nature of ground etc.

PRECAUTIONS:

1.Core cutter should be driven into the ground till the steel dolly penetrates into the ground half way only so as to avoid compaction of the soil in the core.

2.Before lifting the core cutter, soil around the cutter should be removed to minimize the disturbances.

3.All the measurements should measure accuretely.