What's the best way to fix a big sink hole under front porch? The foundation company checked the foundation and told the foundation is fine. There is no crack on front porch. Mud jacking company suggested to do mud jacking. The concrete company suggested to fill out the hole with concrete. A friend told that I should fill out the hole with dirt then build a retaining wall. I don't know what's the best way to fix a big sink hole (2 x 1.5 x 0.18 square meter) under front porch?