What is the 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…
Relevant is Code: IS 2720 part 29
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 20Â
Procedure:
 1) The internal Volume of core cutter shall be calculated by taking dimensions nearest to 0.25 mm (By vernier).
2)Â Cutter shall be weighed to the nearest gm.
3)Â 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)Â 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 the 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.
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
| 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 InformationÂ
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.CÂ (optimum moisture content )& M.D.D (Maximum Dry Density )Â
also, check our core soil moisture content value nearby +5%Â of compere soil.
Core Cutter Method
By using the core cutter method, bulk density of soil can be quickly calculated and by determining the moisture content of the soil the dry density of the fill can be calculated and hence the voids percentage. A high percentage of voids indicates poor compaction of the soil.
Frequently asked questions (FAQs) that could be included in an article about soil compaction
What is soil compaction and why is it important?
Soil compaction is the process of mechanically increasing the density of soil by reducing air voids. It is crucial in construction to enhance soil stability, improve load-bearing capacity, and prevent settling or subsidence of structures.
How does soil compaction affect construction projects?
Properly compacted soil ensures uniformity and stability, which are essential for the longevity and safety of buildings, roads, dams, and other infrastructure. It reduces the risk of structural failure due to settling or shifting ground.
What methods are used for soil compaction?
Common methods include mechanical compactors like rollers or rammers, which exert pressure to compress soil. Techniques vary depending on soil type, moisture content, and project requirements.
What are the benefits of conducting soil compaction tests?
Compaction tests, such as the core cutter method, assess soil density and moisture content. They help engineers determine the optimal compaction effort (compaction energy), ensuring that soil reaches its maximum dry density and optimum moisture content for stability.
What are Maximum Dry Density (MDD) and Optimum Moisture Content (OMC)?
MDD is the highest density achievable for a particular soil type under specific compaction conditions. OMC is the moisture content at which soil can be most effectively compacted to achieve MDD. These values guide engineers in achieving optimal compaction results.
How is compaction testing performed on-site?
On-site testing typically involves using tools like core cutters to extract soil samples, measuring their wet weight, determining moisture content, and calculating dry density. These tests are essential for quality assurance and compliance with construction standards.
What are the consequences of poor soil compaction?
Poor compaction can lead to uneven settlement, structural instability, and increased maintenance costs over time. It may also compromise the performance and safety of structures built on inadequately compacted soil.
How can soil compaction be improved?
To enhance compaction, engineers may adjust compaction methods, moisture content, or use additives like stabilizers or binders. Proper training of personnel and adherence to compaction standards are also critical factors.
Are there environmental considerations related to soil compaction?
Yes, excessive compaction can adversely affect soil fertility, drainage, and water infiltration, impacting vegetation and natural ecosystems. Engineers must balance construction needs with environmental stewardship.
What standards or guidelines govern soil compaction practices?
Standards such as IS 2720 Part 29 provide guidelines for conducting compaction tests in India. Internationally, ASTM and other standards organizations offer similar protocols tailored to different soil types and project requirements.
