Underpinning

Pit Underpinning

Traditional pit underpinning is often used when excavation must be made beneath shallow foundation. This method of underpinning is most often utilized when shallow foundation experience unacceptable levels of settlement, or if an expansion or renovation to an existing structure requires excavation below the bearing surface of the existing foundation. Typically, a pit is excavated directly beneath a portion of an existing footing to the depth of the new bearing surface. The pit is then filled with concrete and dry-packed. Once this process is repeated under the remaining portions of the footing, the underpinning is complete for that foundation.

Micropile Underpinning

If an existing foundation must have its bearing elevation lowered by a large amount, micropile underpinning may be more efficient than a deep, excavated pit. The advantage of this type of underpinning is that it may be accomplished prior to excavation and the versatility of the micropile allows for several load-transfer options.