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Core Cutter Method

What is Compaction of Soil?

compaction of soil is area compacted by mechanical method for remove air voids in compacted soil this area of soil called compaction of soil

Why Use the compaction of soil?

Compaction of soil compacted soil so changes soil property. Soil well compacted and remove air voids in the soil. After done, compaction soil improved soil quality. Also, change the engineering properties of the soil.

This required any construction work like

Road work, Earth dam, Different Concoction type of building, Dam, etc…

Relent is Code: IS 2720 part 29

Also Read : IS CODE FOR CIVIL ENGINEER [Q&A]

This test knows a different name like “Field Density Test,” ” Soil Compaction Test,” Compaction  Test ” ‘” Dry Density of Soil in place by Core – cutter method,” ” Filed Compaction test,” “core cutter method.”

Aim:

To determine the Field density of Fine-grained soil by using core cutter test                                                                                                                                 

Scope:

This procedure covers all relative activity for the project site.

Apparatus:

1).  Core cutter

Core-Cutter – of seamless steel tube, 130 mm long and 10 mm internal diameter, with a wall thickness of 3 mm, beveled at one end, of the type illustrated. The cutter shall be kept properly greased or oiled.IS Code 2720 Part 20 CI: 2.1

2). Dolly / Rammer.

2’5 em high and ten10 mm internal diameter with a wall thickness of 7’5 mm with a lip to enable it to be fitted on top of the core-cutter IS Code 2720 Part 20 CI: 2.2

3).  Balance of 1 gm accuracy.

4). Pallet knife, Straight edge, Steel rule, Pickaxe, etc.

5). Rapid moisture meter

NOTE 1: These designs have been found satisfactory, but alternative designs may be employed provided that the essential requirements are fulfilled. IS Code 2720 Part 20
NOTE 2: Essential dimensions are underlined. (Tolerance on all essential dimensions shall be ±O’25 mm ).IS Code 2720 Part 20 

Procedure:

 1)  Internal Volume of core cutter shall be calculated by taking dimensions nearest to 0.25 mm (By vernier).

2)  Cutter shall be weighed to nearest gm.

3)  A small area, approximately 30 cms square of the soil layer to be tested shall be exposed and leveled.

4) Cutter shall be placed vertically on soil with dolly on top.

5)  Cutter shall be rammed down vertically into the soil layer until only about 15 mm of dolly protrudes above the surface.

6) The cutter shall be dug out of surrounding soil by a pickaxe.

7) Soil from both the ends shall be trimmed flat to the ends of the cutter.

8) The cutter containing soil mass shall be weighed to nearest gm.

9) The soil mass shall be removed from cutter and representative sample shall be tested for water contents with the help of rapid moisture meter.

When soil mass is dry, and the cutter is not properly filled up or looses soil while handling. In such a case test is to be done by sprinkling water and testing after a suitable lapse of time.

Also Read : LAB TEST ON AGGREGATES AT SITE

Calculations of core cutter test:

Bulk Density Yb of Wet Soil is as below:

Yb = (Ws – Wc ) / Vc , gms /cm3

Dry Density Yd is as below:

Yd = 100 Yb / (100 + w ) , gms /cm3 Where w = Water content %

Report: Dry Density to be recorded to 2nd place of a decimal in gms/cm3. Water Content % to two significant figures ( e.g.- 23, 2.3, 0.23 )

Sample of Excel Sheet  FDD by core cutter

Also Read : PROCEDURE FOR RCC CONCRETE

 

FIELD DRY DENSITY BY CORE CUTTER
Location Level
MDD OMC
MDD report no. Tested as per
Description Sample 1 Sample 2 Sample 3
1. Weight of wet soil + Core cutter (W1) ( gms)
2. Weight of Empty Core cutter (W2) (gms)
3. The volume of Core Vc (cc)
4. Weight of wet soil  Ww = W1-W2 (gms)
5. Bulk Density  γ = Ww / Vc (gm/cc)
6. Moisture Meter Reading (R)
7. Moisture Content Wc = R / (100-R) x100
8. Dry density γd  = γ / (1+ Wc) (gm/cc)
9. % Compaction (γd / MDD ) x 100
Remarks ( If Any) –

More Information 

    • This was about the best method for earth compaction. Overall the method for earth compaction  is excellent
    • This method easy to perform on-site at the time.
    • This method requires using soil O.M.C  (optimum moisture content )& M.D.D (Maximum Dry Density ) 
    • also, check our core soil moisture content value nearby +5%  of compere soil.