Hi All,
I am working a design-build project, and we have reached an issue during construction.
We have a small building that we now want to structurally extend. As-builts are limited. During the design, we assumed that the CMU walls extended 2'-0" below grade and were supported by a concrete strip wall footing. Our goal was then to continue the CMU wall and wall footing system, by doweling into both the existing wall and wall footing and continuing the system.
However, after excavating around the structure, we now realize that the walls do not extend 2'-0" below grade, but instead bear on a slab on grade with a thickened edge. There is now a conflict between the as-built condition and the design drawings, and we won't be able to tie in the new wall footing into the existing slab/thickened edge.
The DOR has proposed to underpin the slab to concrete wall footing, as shown in the attached detail. I don't have too much experience with foundation underpinning. Are there any technical difficulties/considerations if we consider this?
Thanks for your time.
I am working a design-build project, and we have reached an issue during construction.
We have a small building that we now want to structurally extend. As-builts are limited. During the design, we assumed that the CMU walls extended 2'-0" below grade and were supported by a concrete strip wall footing. Our goal was then to continue the CMU wall and wall footing system, by doweling into both the existing wall and wall footing and continuing the system.
However, after excavating around the structure, we now realize that the walls do not extend 2'-0" below grade, but instead bear on a slab on grade with a thickened edge. There is now a conflict between the as-built condition and the design drawings, and we won't be able to tie in the new wall footing into the existing slab/thickened edge.
The DOR has proposed to underpin the slab to concrete wall footing, as shown in the attached detail. I don't have too much experience with foundation underpinning. Are there any technical difficulties/considerations if we consider this?
Thanks for your time.