水泥改良含砂高液限粉土路用特性试验研究

Research on the Cement Improvement Experiments of Road Characteristic for MHS

含砂高液限粉土独特的物理力学特征对工程建设极其不利,直接填筑路基,可能产生一系列病害,换填则将增加工程投资成本,且对环境造成影响破坏。为了改善其路用性能,首先研究了其基本性质,取湖南某地土样,采用XRF荧光光谱、 XRD粉晶衍射、薄片鉴定、筛分和液塑限测定等实验方法,分析含砂高液限粉土的成分及结构,发现矿物成分以高岭石居多,会对该类土体的水稳定性造成极大的影响,且其细颗粒含量较大,对其工程性质影响更突出。本文采用水泥改良的方法,并通过试验得出水泥改良该类含砂高液限粉土的施工控制标准:掺率6%,并以最佳含水率为15. 6%、最大干密度为1. 761cm^3作为控制指标用于96区下路床各区路基填筑。

The unique physical and mechanical characteristics of the MHS soil are unfavorable to engineering construction.It may develop a series of diseases if been directly filled roadbed or increase the cost and effect on the environment if exchange filling.In order to improve the road characteristic,soil samples are taken into elementary property test analysis in Hunan.The composition and structure of high liquid silt containing sand were analyzed through XRF,XRD,thin section experiments,screening experiments and liquid-plastic limit combined method.It is found that the mineral composition is mostly kaolinite,which will greatly influence the water stability of this soil,and the influence on its engineering properties is more prominent due to the large content of fine particles.In this paper,the method of cement improvement is adopted,and the construction control standard used for subgrade filling of subgrade bed in zone 96 of this kind silt is obtained by test:the mixing rate of 6%,and the optimum moisture content was 15.6%and the maximum dry density was 1.761cm3 as the control index.