Deep and safe.
Underpinning is often required in cases where a deeper foundation is to be laid next to an existing building. This is particularly important if the incipient excavation removes part of the load transfer zone from the existing structure and there is a risk of settlement or base failure. Underpinning may also be necessary if an existing building is to be subsequently deepened or undercut.
The foundation loads of the shallow-foundation structure can then be transferred to a deeper foundation level via the underpinning body. Underpinning may also be used to increase the exterior load-bearing capacity of the existing foundations or to repair damage resulting from unanticipated impact increases.
The most common underpinning methods include:
- Jet grouting methods
- Use of small-diameter bored piles
- Underpinning walls as per DIN 4123
- Ultra-fine cement grout injection