Method to Quantify Freeze-Thaw Effects on Temperate Climate Soils: Calvert Cliffs

摘要

The Calvert Cliffs form much of the western coastline of the Chesapeake Bay in Calvert County, Maryland, and are actively eroding, resulting in a critical situation for many homes in close proximity to the slope's crest. Past studies have qualitatively shown that where waves do not regularly interact with the slope toe, the main control mechanism for slope recession is freeze-thaw events. In this study, an attempt was made to quantitatively assess the validity of this claim by analyzing the recession rate and freeze-thaw behavior of six study sites along the Calvert Cliffs that are not directly affected by waves. The freeze-thaw susceptibility of soil can be quantified by assessing its material and thermal properties. The freezing can also commonly be quantified using a freezing index. For a temperate climate like that of the Calvert Cliffs, however, a freezing index is not an effective way to quantify freeze-thaw behavior due to a lack of a well-defined freezing season. Instead, the study investigated the following two parameters: (1)days of freezing, and (2)number of freeze-thaw cycles, in addition to freeze-thaw susceptibility, to quantify freeze thaw. Results indicate that using days of freezing and/or freeze-thaw cycles may be more appropriate metrics for quantifying the effects of freeze-thaw in temperate climates like that of the Calvert Cliffs.