Lab reports on determination of field density of soil mass by sand replacement method

 

TITLE: DETERMINATION OF FIELD DENSITY OF SOIL BY SAND REPLACEMENT METHOD

OBJECTIVES:

• To determine the field density of soil mass by sand replacement method 

APPARATUS REQUIRED:

•            Sand – pouring cylinder

•            Calibrating container, 100mm diameter and 150mm

•            Soil cutting and excavating tools

•            Plane surface: Glass or Other Plane Surface

•            Metal container to collect excavated soil

•            Metal tray, 300mm square and 40mm deep

with a hole of 100mm in diameter at the center

•            Weighing balance accurate to 1 gram

•            Moisture content cans

•            Oven

MATERIALS REQUIRED:

•      Clean, uniform sand passing 1mm IS sieve and retained on 600 micron IS sieve in sufficient quantity. It is required to be free from organic substances. The sand should have been dried in an oven and kept in suitable storage for a period of time to allow its water content to reach equilibrium with atmospheric humidity.

  

THEORY: •

The in  situ dry density of soil. The procedures, materials, equipment, and specifications of this test is based on the Indian Standard (IS 2720 part 28). This test is of significant importance and it has been widely used in various construction project sites.

•            The sand replacement test method is also used to determine the in-place density of compacted soil in order to compare it with the designated compaction degree, hence it specifies how much the compaction of the soil is close to the designated compaction degree.

Calibrations

              1.First of all, Measure the internal dimensions of the calibrating container and then calculate its volume.

 Fil2.the sand-pouring cylinder with sand, within about 10mm of its top. Determine the weight of the filled cylinder (M₁).

•            3.Place the sand-pouring cylinder vertically on the calibrating container. Open the shutter to allow the sand run out from the cylinder. When there is no further movement of the sand in the cylinder, close the shutter.

•            4.Lift the pouring cylinder from the calibrating container and weigh it to the nearest gram (M2).

•            5.Place the sand pouring cylinder on the glass plate. Open the shutter and allow the sand to run out of the cylinder until no further movement of the sand is noticed (sand fills the cone of the cylinder), and then close the shutter and remove the sand pouring cylinder carefully.

•            6.Take the sand on the glass plate and determine its weight (M₃)

•            7.Repeat step 3 to step 6 two more times and record mean weight (mean M₂ and M3)

•            8.  Determine the dry density of sand, as shown below.

bb    CALIBRATION FOR DRY DENSITY OF SAND:

1.        Diameter,D=100 mm
2.       height of container,H=150mm
3.      Volume of container,V=
4.       Mass of pouring cylinder filled with sand (M1)=
5.       Mass of pouring cylinder after pouring sand into the calibrating container and cone (M2)=
6.       Mass of sand in the cone (M3)=

      Calculation:

          mass of sand in calibrating container,Mc=M1-M2-M3=

          Dry density of sand,p =Mc/V=

 

        FIELD PROCEDURE:

  1.    1.Expose an area of about 450mm square on the surface of the soil mass. Trim the surface down to a level surface using a scrapper tool.

•              2.Place the metal tray on the leveled surface.

•            3.  Excavate the soil though the central hole of the tray, using the hole in the tray as a pattern. The depth of the excavated hole should be about 150mm.

•                4. Collect all the excavated soil in a metal container, and determine the mass of the soil (M).

•                5.Remove the metal tray from the excavated hole.

•               6.Fill the sand pouring cylinder within 10mm of its top. Determine its mass (M₁).

•                7.Place the cylinder directly over the excavated hole. Allow the sand to run out the cylinder by opening the shutter. Close the shutter when the hole is completely filled and no further movement of sand is observed.

•              8. Remove the cylinder from the filled hole. Determine the mass of the cylinder (M₄).

•              9.Take a representative sample of the excavated soil. Determine its water content.

•              10.Determine the dry density of soil as shown in Table 2.

        OBSERVATION AND CALCULATION FOR FIELD DENSITY:

1.             Mass of excavated soil , M=
2.           Mass of pouring cylinder, filled with sand,(M1)=
3.          Mass of cylinder after pouring into the hole and cone,(M4)=

CALCULATIONS:

        Mass of sand in the hole,Ms=M1-M4-M3

       Volume of sand in the hole,V=Ms/Ps=

        Bulk density p=M/v=

        Water content,w=

         Dry density,Pd= P/(1+w)=

       

       RESULT:

       From above field procedure and calibration test , we have found:

        Density of sand, Ps=

         Field Density of soil, P=

        Dry density of soil,Pd=

CONCLUSIONS:

Hence , by this way, we can calculate the field density of soil in field. The field density may vary place to place dedending upon th soil composition, natural water content,ground condition etc. This method can use for cohesive as well as non-cohesive soil.

PRECAUTIONS:

1. All the measurement should measure accurately.
2. The shutter should close toghtly after pouring of sand to prevent spill out.
3. The depth of excavation should nearly equal to 10 cm dia and about 15 cm depth for precise data measerement.
4. Excavated soil should collect without spilling over pan.

LAB REPORS OF SOIL MECHANICS

 

      

List of Practical
SN	List of Practical
1.	Determination of specific gravity and water content of soil
2.	Grain size analysis of soil (i.e. Sieve Analysis and Hydrometer Analysis)
3.	Determination of wet density of soil.
4.	Consistency Limits Test for fine-grained soil (i.e. LL, PL, and SL)
5.	Compaction Test
6.	Direct Shear Test
7.	Triaxial Test (Demonstration)
8.	Unconfined Compression Test
9.	Vane Shear Test
10.	Consolidation Test (Demonstration)
11.	Visual Classification Test of Soil (Demonstration)
12.	Experimental demonstration of water effect on sandcastle

 FIND HERE PDF FILES:

 soil mechanics lab 3.pdf

soil mechanics lab 4.pdf

soil mechanics lab 5.pdf

soil lab 6.pdf

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, theheight (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)=
2. Weight of core cutter+ soil (M2)=
3. Height of core cutter (H)=
4. Internal Diameter of core cutter (d)=
5. volume of core cutter (V)=

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

RESULT:

From the above field procedure ,we have calculated the field density of soil as P=...........

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.