摘要
研究目的:长沙至益阳城际铁路宁乡境内广泛分布Q2网纹状红黏土,这种土体性质有很强的区域性,城际铁路对路基的沉降变形控制十分严格,所以针对此类路基如何采用合理的处理方法是一个关键问题。为了全面了解宁乡Q2网纹状红黏土的工程性质,结合现场地质调绘、钻探、原位测试及室内试验,对土体的形态成因、物理性质、强度特性、变形固结特性以及膨胀特性进行系统的探讨,为路基设计提供可靠的依据。研究结论:网纹状土是在湿热的气候条件及多水的环境下,红黏土经多次淋溶沉淀作用而形成;网纹土的孔隙比比一般黏土要大,饱和度一般低于90%,为非饱和土;液限及液性指数较高,为高液限土;天然状态下网纹土的强度较高,一般处于硬塑～坚硬状态,承载力可达200 kPa;网纹土属于中压缩性土,下层网纹土压缩性比上层土要高;网纹土是典型的超固结土,表层的超固结比达到15.4;网纹土一般为弱膨胀土。
Research purposes： The Q2 overlapping clay soil is widely distributed in Ningxiang along the Changsha - Yiyang Railway and it is hardly found in other regions. To choose the proper method to treat this type of soil is the key problem because the subgrade settlement of intercity railway must be controlled strictly. Through the in - situ investigation, drilling exploration, in -situ test and indoor experiment, etc, the study is done on the soil g morphology and genesis, physical property, strength characteristics, deformation consolidation and expansive property to know the engineering characteristics of the overlapping clay soil for providing the reliable basis for the subgrade design. Research conclusions：The overlapping soil is formed from the red clay caused by the effect of leaching and depositing under the warm and wet environment, and it is a typical unsaturated soil with void ratio being bigger than red clay and saturation degree always being less than 90%. The overlapping soil with high liquid limit and high liquidity index is a high liquid limit soil. This soil is generally in plastic - hard status with strong strength and its bearing capasity can reach to 200kPa in natural condition. The overlapping soil belongs to the medium compressible soil, and the compressibility of the overlapping soil in the low layer is bigger than the soil in the upper layer. This soil is a typical over - consolidated soil with the over consolidation ratio of surface soil up to 15.4 and the overlapping soil belongs to weak expansive soil.
出处
《铁道工程学报》
EI
北大核心
2011年第10期25-29,共5页
Journal of Railway Engineering Society
关键词
网纹状红黏土
工程地质特性
前期固结压力
膨胀性
overlapping red clay soil
engineering geological property
preconsolidation pressure
expansibility
