Volume change behavior of reconstituted marine clay: effect of initial and leaching pore fluid salinity

Abstract

Because the salinity of marine clay changes continuously in response to the migration of seawater toward land or freshwater from river to sea, the intrinsic pore fluid salinity of the clay-water system may change periodically. Recent studies indicate that pore-water salinity changes the intrinsic properties of reconstituted homoionic artificial clay. However, the effect of seawater on the intrinsic properties of marine clay is unknown. The aim of this study was to investigate changes in the compression parameters of marine clay for the leaching salinity of seawater with respect to tap water. The results show that ratio $${e}_{0}/{e}_{\mathrm{L}}$$ is more sensitive to salinity than $${e}_{100}^{*}$$ . Although the Iv − log p for all samples at different intrinsic/leaching salinities were located on the intrinsic compression line (ICL); some deviation from the ICL was observed at low-stress levels. In high-salinity reconstituted samples, the osmotic gradient caused the low-salinity water to penetrate the clusters and separate individual particles, increasing the size of intra-cluster pores and settlement during consolidation. The distance between the particles at any stress level was larger than in diffuse double layer theory because of a deviation from the assumed parallel fabric in the theory.