The sand-filled geotextile tube is common, and has been well-established in coastal engineering applications. However, the use of soft clay or dredged material as the infill material for geotextile tube containment bunds is not widely used due to technical concerns on the stability and excessive settlement of the geotextile tubes. To minimize shape deformation and settlement of geotextile tubes associated with the use of soft clay, a modified infill material is proposed – lightly cement-mixedsoil (CMS). This study is aims to investigate the response of a full-scale, instrumented geotextile tube of 20m length, 12.6m circumference and inflated height of approximately 2m when filled with lightly CMS and subjected to surcharge. The surcharge simulates the condition where the geotextile tubes are stacked on top of each other to form a containment bund. The shear strength development at 3-days and 7-days curing of the CMS were also evaluated. This study will provide valuable insights into the design and construction of containment bunds using geotextile tubes infilled with soft clay or dredged material.