ABSTRACT This research mainly sought to evaluate the sediments of the Urmia lake bed to prevent their erosion and the possibility of improving the problematic saline fine soils in the region by the geo-polymerisation process. For this purpose, perlite and pumice materials, with pozzolanic properties and weight percentages of 3, 5, and 7, were separately mixed with soil, along with the calcium hydroxide (Ca(OH)2) solution as a catalyst with 2%, 5%, and 7%. Then, the samples were cured for one day. Uniaxial compressive strength (UCS), direct shear, and consolidation tests were performed to assess the geotechnical properties of improved soil compaction. The results revealed that, compared to pumice, perlite could improve the behavioural properties of the studied soil. The inclusion of perlite and pumice, along with calcium hydroxide, increased the flexibility of the stabilised soil, as indicated by the brittleness index. Similarly, combining 3% perlite with 2% Ca(OH)2 could increase UCS at failure by 3.27 times. In addition, the mixture of 5% perlite with 7% Ca(OH)2 could enhance the shear strength by 3.3 times. Finally, combining 3% perlite with 5% calcium hydroxide reduced the swelling of the improved soil by 82%, and the consolidation settlement was decreased by 64% on average.