Uniaxial compression test of cement-solidified dredged slurry columns encased with geogrid

Abstract

This study investigated the performance of unreinforced and geogrid-encased cement-stabilized dredged slurry columns by uniaxial compression tests to simulate the extreme case where the surrounding soil offers no confinement. The objective was to understand the strength characteristics and visualize the deformation damage patterns of the columns with respect to the water content, cement content, length-to-diameter ratio, and geogrid strength. The results show that the unreinforced specimens exhibited strain-softening behavior, whereas geogrid encasement induced strain-hardening, with high-strength geogrids showing superior strain-hardening capacity. Notably, regardless of geogrid strength, encasement enhanced the resistance to deformation and ductility of the columns. Increasing the cement content, reducing the water content, and decreasing the length-to-diameter ratio all contributed to higher peak strength in both unreinforced and geogrid-encased specimens. Geogrid encasement provides confinement that enhances peak strength. The influence of geogrid encasement on peak strength becomes more pronounced at lower cement contents, higher water contents, and higher length-to-diameter ratios. Geogrid encasement also affects failure modes, altering the predominant inclined shear failure observed at the top of unreinforced specimens. Specimens encased with geogrids of higher tensile strength exhibit enhanced integrity and deformation resembling compression strut buckling, with a symmetrically inclined failure trend at the top and bottom.