Multi-Under-reamed Piles in Expansive Clayey Soil

Multi-under-reamed piles are a type of pile foundation that consists of a series of bored piles interconnected with a horizontal concrete beam. These piles are commonly used in areas where the soil is weak or has low bearing capacity. The under-reamed portion of the pile refers to an enlarged bulb-like shape at the bottom of the pile, which provides increased bearing capacity.

Expansive clayey soil is a type of soil that undergoes significant volume changes due to changes in moisture content. The soil swells when it absorbs water and shrinks when it dries out. This type of soil can cause significant damage to structures if not properly accounted for in the foundation design.

Multi-under-reamed piles are particularly suited for expansive clayey soil due to their ability to distribute the load over a larger area and resist the heave caused by soil volume changes. The enlarged bulb-like shape of the under-reamed portion of the pile ensures that the pile remains anchored in the soil even when the soil swells.

In addition, the interconnected nature of the pile system provides additional stability and resistance to lateral forces. The horizontal concrete beam connecting the piles helps to distribute the load evenly and prevent differential settlement.

Therefore, multi-under-reamed piles are an effective solution for building foundations in expansive clayey soil, providing a stable and durable foundation that can withstand the challenges of this type of soil.