The house’s foundation was down 7′, while the garage only had a floating slab. To get the foundation in, we had to dig down 7′ and remove the soil. The soil we were digging in was sand. Digging this close to the garage the sand under garage will slide out fast and up 7′ away from the garage under mining the garage, then the garage floor will break, this will bring the broken slab and some of the garage wall framing into the excavated hole. to solve this problem we built a shear wall to hold sand from shifting and sliding, keeping the garage safe.