东北五常地区淤泥质软土指标相关性分析

Correlation Analysis of Silty Soft Soil Index in Wuchang Area of Northeast China

岩土体参数具有区域性特点,开展区域性土的物理力学参数相关性研究极具实践价值。通过对95组东北五常地区淤泥质软土物理力学指标的统计分析,得到以下结论和建议(1)该淤泥质软土具有高含水率、高压缩性、大孔隙比和强度低的软土特性,但物理力学参数变化范围大,变异系数高,平均抗剪强度略高于沿海地区淤泥质软土;(2)天然密度、干密度与天然含水量之间呈现高度相关的对数关系;(3)天然含水率w、液限wL、塑限wP与塑性指数IP、液限wL和塑限wP呈现高度相关线性关系;(4)孔隙比e与天然含水率w、天然密度ρ、干密度ρd高度相关,分别呈线性和指数关系,与颗粒比重Gs呈现显著的对数关系。(5)压缩模量Es1-2和压缩系数a1-2与天然含水量w、天然密度ρ、干密度ρd以及孔隙比e等4个指标几乎都具高度相关性,表明这些参数对土体的变形影响很大;与颗粒比重Gs中度相关,与液性指数和饱和度无相关性。抗剪强度参数与上述7个物性指标间的拟合结果却反映了无相关性。文中拟合得到了一些有价值的经验公式,以期为五常地区工程设计中淤泥质软土参数取值提供参考和依据。

The geotechnical parameters have regional characteristics and it is of great practical value to study the correlation of physical and mechanical parameters.Based on the statistical analysis of physical and mechanical indexes of 95 groups of silty soft soil in Wuchang area of northeast China.The following conclusions and suggestions are obtained.First,the silty soft soil has the characteristics of high water content,high compressibility,large pore ratio and low strength,but the range of physical and mechanical parameters is large,the coefficient of variation is high,and the average shear strength is slightly higher than the coastal silty soft soil.Second,natural density,dry density and natural water content are highly correlated logarithm.Third,natural moisture content,liquid limit and plastic limit are highly correlated with plastic index,liquid limit and plastic limit.Fourth,the pore ratio is highly correlated with natural moisture content,natural density and dry density,with linear and exponential relationships respectively,and has a significant logarithmic relationship with particle specific gravity.Fifth,compression modulus and compressibility are highly correlated with natural water content,natural density,dry density and pore ratio,which shows that these parameters have great influence on soil deformation.It was moderately correlated with particle specific gravity,but not with liquid index and saturation.However,there was no correlation between the shear strength parameters and the physical properties.Some valuable empirical formulas are obtained by fitting to provide reference and basis for parameter selection of silty soft soil in engineering design of Wuchang area.