Classes About Under reamed pile

Under reamed pile :

                                 Under reamed piles are bored cast-in-situ concrete piles having one or more number of bulbs formed by enlarging the pile stem. These piles are best suited in soils where considerable ground movements occur due to seasonal variations, filled up grounds or in soft soil strata.
                                                

Uses of under reamed pile :
                         .Under-Reamed Piles are widely used for different types of soils such as sandy soils, clayey soils and also expansive soils.

1. To avoid the undesirable effect of seasonal moisture changes in expansive soils such as black cotton soils.
2. To reach hard strata.
3. To obtain adequate capacity for downward, upward, lateral loads and moments.
4. To take the foundations below the scour level.
5. They have also been found useful for factory buildings and machine foundations.
6. Under-Reamed Piles are also used under situations, where the vibration and noise caused during construction of piles, are to be avoided.

• Advantages of under reamed pile :

1. It decreases the vertical settlement and also differential settlement.
2. It is used when soil tends to swell and shrink due to moisture variation or expansive nature of the soil.
3. Provision of under-reams or bulbs has the advantage of increasing the bearing and uplift capacities.

• Disadvantages of under reamed pile :
• At a depth, where nature of soil varies with a climatic condition, Under-Reamed Piles are not suitable for waterlogged soil, as they take load by friction.
• These piles need strict quality control and regular supervision during the construction.
• Most of the times, Under Reamed Piles are driven manually with hand operated machine. Hence maintaining plumb of pile is very essential, because if they are not in plumb whole load transfer mechanism would change.


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