湖相沉积细粒土不同锥入度液塑限相关性试验研究

Experimental study on the correlation between different coning degrees and liquid plastic limits of fine grained lacustrine sediments

由于各行业相关土工试验标准存在一定差别,跨行业进行勘察设计就显得非常不便。为使各标准间尽量做到无障碍衔接,现以昆明高原湖相沉积的细粒土为研究对象,参照国内外不同行业相关标准及土工试验方法,对2 388个细粒土样的天然含水率ω、液限ω与塑限ω等指标进行了试验,并收集了昆明地铁五号线大量泥炭质土物理力学指标的试验资料进行相关性分析。结果表明:细粒土在平衡锥下沉深度为10 mm的液限ω与17 mm的液限ω间都存在线性相关关系,并用99%可靠性判断ω对ω有显著影响;由转换的ω与直接采用ω计算的平均稠度一致,判定的干湿类型完全相同;细粒土与泥炭质土的液塑限间同样存在线性关系;所得关系式适用于湖相沉积地区,可以实现该区域指标间的换算,降低勘察项目成本以及缩短试验周期。

As there are certain differences in relevant geotechnical test regulations of various industries, it is very inconvenient to carry out survey and design across industries.In order to make the barrier-free connection among the standards as far as possible, the fine grained soil of lacustrine sediments in Kunming Plateau was taken as the research object, and the natural moisture content ω,liquid limit ωand plastic limit ωof 2 388 fine grained soil samples were tested according to the relevant standards and geotechnical test methods of different industries at home and abroad.A large number of experimental data of physical and mechanical indexes of peat soil in Kunming Metro Line 5 were collected for correlation analysis.The results show that there is a linear correlation between the liquid limit ωof 10 mm and the liquid limit ωof 17 mm, and the effect of ωon ωis determined with 99 % reliability.The average consistency calculated by ωis consistent with that calculated directly by ω,and the types of dry and wet are exactly the same.There is also a linear relationship between the liquid plastic limit of fine soil and peat soil.The relationship obtained is suitable for lacustrine sedimentary area, which can realize the conversion between the indexes in this area, and reduce the cost of survey project and test period.