Abstract: With the increasingly versatile application scenarios of cemented soils piles and cemented soils anchor used as energy piles and energy anchors and other energy geotechnical structures,the cemented soils serving as binders and heat change materials are required to meet the dual requirements of mechanical and thermal properties.As a type of industrial solid waste,iron tailing sands demonstrate good thermal conductivity due to its contented metal components,and deemed as a potential substitute of a part of soils to improve the thermal conductivity of cemented soils.In this study,an experimental investigation was carried out to explore the microstructure and the thermal-mechanical properties of cemented soils with different substitution rate of iron tailing sands.Hence,the impact of substitution rate of iron tailing sands on the thermal and mechanical performance indices of cemented soils was investigated.The following concluded remarks can be found.The increasing substitution rate of iron tailing sands leads to the improvement of the thermal conductivity of cemented soils,in which a maximum increase of 77.4% can be found with specimens under long-term curing condition.The increasing substitution rate of iron tailing sands results in the deduction of the compressive strength of cemented soils,with the maximum reduction of 18.4%;but results in the enhancement of the flexural strength of cemented soils,with the maximum increment of 20.3%.The microstructural analyses reveals that the substitution rate of iron tailing sands affects the thermal conductivity of cemented soils via pore space effect,medium filling effect,and medium transmission effect;and affects the mechanical performance of cemented soils via the effect of hindrance of cementhydration,the effect of competition effect for heavy metals,and the effect of reduction of active minerals.