Pit underpinning stabilizes structures prior to adjacent excavation, using concrete and mortar.
A limited width pit (panel) is excavated and shored by hand below the structure and extends to the design depth. The pit is then filled with concrete, leaving several inches of space under the bottom of the structure. Mortar is then packed into the space to provide the load transfer. After the concrete and mortar reach sufficient strength, additional adjacent panels can be constructed as necessary.