陕西某750 kV变电站回填膨胀土改良试验研究OA

To address the problem of backfilled expansive soil in power engineering sites,laboratory tests were carried out to investigate the shrink-swell characteristics and physical-mechanical properties of improved soil samples treated with lime at different mass mixing ra-tios(2%,4%,6%,8%)for a curing period of 7 days and cement at mixing ratios(4%,6%,8%,10%)for 14 days.The improve-ment effects of lime and cement on expansive soil were compared systematically to explore the optimal improvement scheme.The results show that both materials can significantly increase the compression modulus and strength of the soil and effectively inhibit its shrink-swell deformation.Lime exhibits a superior performance in inhibiting shrink-swell deformation:a 4%mixing ratio can reduce the free swelling rate from 73.3%to below30%,and a6%mixing ratio can basically eliminate the swelling deformation.In contrast,cement has a better effect on improving the early strength and stiffness of the soil.Lime with a mixing ratio of not less than 4%is recommended as the optimal scheme for the improvement of backfilled expansive soil in the site levelling of this project.The research results have engineering signifi-cance and reference value for the improvement of expansive soil in similar projects.