Compressibility Of Marine Clay Research Articles

Experimental Evaluation of Leaching Effects on the Compressibility of Marine Clay and its Strain Rate Dependency

This study investigated how leaching affects compressibility behavior of marine clay and its strain rate dependency based on laboratory tests using three pairs of specimens. Each pair of specimens consisted of leached and unleached samples with identical geotechnical properties except soil salinity. The behavior characteristics of the leached and unleached specimens were evaluated using several series of constant rate-of-strain (CRS) tests with differing strain rates. The results revealed that the compressibility of leached clay increased as its salinity decreased. However, void ratio, Atterberg limits, and preconsolidation pressure in leached samples were lower than those in unleached clay. The increased compressibility and decreased preconsolidation pressure may be induced from a weakening of the interparticle bonds in the leached soil skeleton. The CRS test results with differing strain rates revealed that higher strain rates corresponded with higher levels of effective stress and higher apparent preconsolidation pressure in both leached and unleached clays.

Compressibility behaviour of lime-treated marine clay

The necessity to tap natural marine resources from the ocean beds represents a considerable challenge for the construction of offshore structures on weak marine deposits. The use of lime to improve the behaviour of soft clays is not new. The present investigation examines lime-induced changes in the compressibility of marine clay. The test results indicate a reduction of 1/2 to 1/3 in the compressibility of the soil system within 30 to 45 days of treatment. The formation of various cementation compounds due to soil–lime reactions improves the soil characteristics with time. The results encourage the application of lime column and lime injection techniques to improve the engineering behaviour of soft marine clayey deposits. However, one has to be cautious in applying the lime technique to marine clays that contain sodium sulfate.