Underpinning means support or strength. Underpinning is a process by which support is provided on the existing structure.
Definition of Underpinning
Underpinning is the process of constructing a new foundation beneath an existing foundation or strengthening an existing foundation without affecting the stability of the structure.
Situation demand process of underpinning
Following situation demand process of underpinning
i) When a basement is to be provided under an existing structure.
ii) When a new building with a deep foundation is to be built adjacent to the existing building.
iii) When serious cracks developed in the wall due to the settlement of the foundation. In this situation, underpinning process is very essence.
Which points should be considered before starting underpinning work?
Before beginning underpinning work, the following points should be carefully considered.
i) The structure should be fully strutted and shored to resist all expected movements during underpinning.
ii) All cracks in the structure should be repaired and grouted properly.