Underpinning in construction refers to the process of strengthening and reinforcing the foundation of an existing building or structure. It is typically required when the original foundation is no longer strong enough to support the load or has been compromised in some way. Underpinning may be necessary due to various reasons such as changes in the soil supporting the foundation, structural modifications, nearby construction activities, or natural disasters like earthquakes or floods.
The underpinning process involves reinforcing the existing foundation, strengthening the soil by introducing an expanding filler, or extending the foundation to distribute the load over a greater surface area. This can be achieved through various methods such as mass concrete underpinning, beam and base method, micropiles, and jet grouting, depending on the specific requirements of the structure and the soil conditions.
In summary, underpinning is a critical construction procedure that ensures the stability and integrity of existing buildings and structures, especially when the original foundation is no longer adequate to support the load or has been compromised due to various factors.
