石灰改良砂土渗透特性研究

Study on Permeability Characteristics of Lime-Improved Sand

【目的】改善砂土结构松散、抗渗性差的特性。【方法】采用石灰作为改良剂,对不同掺灰量(0%、5%、8%、12%、15%)下的砂土进行室内渗透试验,研究改良砂土的渗透特性变化规律,并建立改良砂土的渗透模型。【结果】研究表明:石灰掺量与改良砂土最大干密度呈负相关,与最优含水率呈正相关;改良砂土饱和渗透系数随掺灰量增加先逐渐减小,再反向增大,12%石灰改良砂土渗透系数最小;改良砂土的石灰掺量与渗透系数呈二次函数关系。【结论】在渗透性满足要求的情况下,考虑经济成本,建议改良砂土最优掺量为8%。

[Purposes]To improve the characteristics of the loose structure and poor impermeability of sand.[Methods]Using lime as an improver,indoor permeability tests were carried out on the sand with different amounts of ash doping(0%,5%,8%,12%,15%)to study,the change law of permeability characteristics of improved sand and establish the improved sand permeation model.[Findings]The results show that the lime content is inversely proportional to the maximum dry density of the improved sand and proportional to the optimal moisture content.The saturated permeability coefficient of improved sand gradually decreases with increasing ash doping,and then increases in reverse,and the permeability system of 12%lime-improved sand is the smallest.The lime content of the improved sand has a quadratic function relationship with the permeability coefficient.[Conclusions]Under the condition that the permeability meets the requirements and taking economic factor into considerations,it is recommended that the optimal content of the improved sand is 8%.