EFFECTS OF SALTWATER INTRUSION ON THE COMPRESSIBILITY BEHAVIOR OF THE EVERGLADES SOILS

The Florida Everglades is considered as a vulnerable wetland composed primary of organic rich peat soils, experiencing saltwater intrusion. Impact of increasing salinity on the strength and deformation properties of peat is unknown. A laboratory study was undertaken to evaluate how the growing salinity level due to sea level rise may alter the compressibility behavior of the Everglades soils. Sixteen 1-dimensional oedometer tests were conducted on undisturbed Everglades peat soils in two phases. Phase I included samples from Site 1 (saltwater) and Site 3 (freshwater) without any salinity addition. Phase II consisted of soil from Site 3 (freshwater) saturated in six different levels of salinity artificially added to the samples. Compressibility properties investigated in this study include compression index (Cc), coefficient of consolidation (Cv), hydraulic conductivity (K), and the Ca/Cc ratio. In general, it was observed that the increase in salinity beyond a threshold value tends to increase the soil compressibility properties, indicating a possible reduction in soil stability with saltwater intrusion.