We knew that the improper compaction of concrete would reduce the strength of the concrete element. Same applies for soil. Both the compaction and consolidation process is involved in construction to make changes in the volume of soil.
Since the ground soil is often removed from its origin for different works such as foundation, basement, plinth beam, the compaction of the soil sub-structure will be disturbed from its nature. So proper compaction and consolidation process are required to attain its original density.
The compaction work is done mechanically or manually by the vibrator for proper settlement.
What is Compaction?
The compaction is a mechanical process to reduce the volume of sub-soil structure by expelling the presence of air between the voids in soil and make the soil hard.
To attain the compaction to its Maximum Dry Density (MDD) the soil should be at Optimum Moisture Content (OMC).
We have discussed the same in the bulking of sand. Using 5-8% of water reduces the bulkage of sand; the same applies here.
What is Consolidation?
The consolidation is a slow manual process to reduce the volume of sub-soil structure by expelling the presence of water between the voids in the soil.
To consolidate the soil, water is sprinkled 2 to 3 times at a specified interval period.
Difference between Compaction and consolidation
The difference between the process of consolidation and compaction have been listed below.
| Compaction | Consolidation |
| Expulsion of air voids | Expulsion of water voids |
| The Compaction process can be completed immediately. | It is a slow and steady process which takes time. |
| The compaction is a mechanical process either it can be done by an earth rammer or roller. | The consolidation of soil is a manual process done by water. |
| The dynamic load applied to compact the soil | The static load applied in long periods to settle down the soil. Usually, the structure or building. |
| The foundation settlement will be reduced | Consolidation is the responsibility for the foundation settlement. |
| During the compaction process, the soil dry density increases but the water level is the same. | The dry density of soil increases during the consolidation process, but the water level will be reduced. |
| The soil should be at Optimum Moisture Content (OMC). | The soil is saturated to settle down the particles. |
| The bearing capacity of soil will increase. | The bearing capacity of soil will increase. |
| The compaction work will be complete before the construction work. | The consolidation work will be completed during and after the construction period. |
| Shear strength of soil will increase. | Shear strength of soil will increase. |
Happy Learning 🙂
