The present study investigated the influence of biochar on various geotechnical properties of clayey soil. Biochar, a carbon-rich product, was amended with the soil at different percentages such as 5, 10 and 15%. Laboratory tests were conducted to evaluate the feasibility of utilization of biochar in enhancing the integrity of soil slopes with an emphasis on landfill covers and bioengineered slopes. Scanning electron microscopy (SEM) tests were conducted to analyse micro-porous structure of biochar and soil-biochar mix. The SEM micrographs indicated the porous structure of the biochar and a good interaction with the clay particles. It was concluded from the present study that the biochar amended soil can have steeper and stable slopes compared to soil without biochar amendments. The compressibility of the soil was also decreased with biochar amendment. © 2021, Springer Nature Singapore Pte Ltd.