This structure in Londonderry, NH was gradually sinking over time. It was supported by concrete piers, however the soil surrounding these piers was eroding, and so the piers were sinking more and more each year. Erickson Foundation Supportworks installed EZ Post piers under the existing structure, along with new PT posts. The new post piers went more than 6ft deep, and so will not sink.
Photos all courtesy of R. Guaraldi.