Our firm is involved in a project in SW Florida where the floor slab of a refrigeration warehouse has heaved and failed due to freezing of the upper 15 feet of soil beneath the slab. This occurred due to a failure in the sub-floor heating system. Once the sub-floor heating system is repaired, the client would like to know how long it will take for the frozen ground to thaw. Is there a procedure or document which provides an analytical means of estimating the thaw rate? The soil is predominantly sandy in nature.