Effect of Moisture Content on Shear Strength of Offshore Clay Interface Steel Surface

This paper investigates the effect of moisture content on interface shear strength between offshore clay and steel plate. Although, sensitive and high plasticity offshore clay deposits are widely distributed in Malaysia and many other countries in the world, and steel is a vital construction material for many structures, research works on interaction between offshore clay and steel surface are relatively scarce. This study aims to evaluate interface shear strength of offshore clay with various steel surfaces, namely smooth, rough, and corroded. To achieve such aim, direct shear tests were conducted to assess the effect of moisture content and surface roughness on the interface shear strength. The normal stresses were ranged to be 50, 100, and 150 kPa. It was found that, the interface shear strength of offshore clay with rough steel significantly increased by almost 1.5 folds. It was further discovered that, addition of water content induced a progressive decrease in the interface shear strength. In summary, it has been observed that rough steel surface higher than the smooth and corroded steel surface enables a better interaction with offshore clay, enhancing the interface friction angle. The results developed in this research work can contribute a cost-effective design of structures in offshore clay.