硅灰改良膨胀土室内试验研究

Laboratory Experiments on Stabilization of Expansive Soil by Silica Ashes

膨胀土是一种具有遇水膨胀、失水收缩、多裂隙性的特殊性黏土.针对膨胀土的不利工程特性,本文采用硅灰作为膨胀土改良剂,研究了硅灰改良土的膨胀性、水稳性及物理力学特性.试验结果表明:硅灰改良膨胀土的液限减小,塑性指数明显降低,自由膨胀率及线膨胀率较素土均有大幅降低;在经历4次干湿循环后,表面未产生贯穿裂隙,其抗剪强度及无侧限抗压强度均有明显提升,水稳性显著改善.这说明了硅灰对膨胀土具有良好的改良效果,对膨胀土地区路基边坡防护具有一定的推广应用价值.

Expansive soil is a special type of clay that has the characteristics of water swelling, water loss shrinkage and muhiple fissures. The expansibility, water stability and physico mechanical properties are studied by using silica ashes as the expansive soil improver. The results of the experiments show that the liquid limit and plasticity index of expansive soils improved by silica ashes are both reduced; and the free expansion rate and the linear expansion rate are significantly lower than that of the plain soil. After four wet ting drying cycles, the surface has not been perforated. The shear strength and unconfined compressive strength have been significantly improved; and the water stability has been significantly improved. So as to show that the silica ashes has a good improvement effect on the expansive soil; and it has a certain application value for protecting subgrade slopes.