【摘要】 针对以往在膨胀土粘土矿物认识上的局限性、现行规范中判别土的膨胀潜势方法的缺陷以及公路施工中遇到的严重膨胀土工程地质灾害等问题,对广西南宁-友谊关高速公路宁明段膨胀土的物质成分、理化特性及工程性质等开展了多项试验研究.分析了膨胀土的成因类型、分布特征及干燥活化作用的影响.扫描电子显微镜(SEM)和X-射线衍射(XRD)鉴定结果表明:宁明段膨胀土的主要粘土矿物成分为高混层比伊利石/蒙脱石(I/S)混层矿物,而不是伊利石.本研究还对该土的膨胀势做出了较为合理的判断,并提出了处治路基病害的方法.更多还原

【Abstract】 Considering the knowledge in identification of expansive clay mineral, the defect of how to identify the expansion potential of soil in current specification and the serious geological hazard of expansive soil in the road construction, a study on material composition, physical-chemical property and engineering properties of the expansive soil in Ningming section of Nan-You highway was carried out, and the influence of the genetic type, the distribution feature and the drying and reactive action on expansive soil was also analysed in this paper. The results of SEM and XRD have shown that the main clay mineral component is I/S mixed-layer mineral, not illite(it is different from the people’s knowledge before).The method to identify the expansive soil and the suggestion to treat the subgrade have also be given.更多还原