南京及邻近地区新近沉积土的动剪切模量和阻尼比的试验研究

通过对南京及其邻近地区漫滩相成因的粘土、粉质粘土、淤泥质粉质粘土、粉质粘土与粉砂互层土、粉土、粉细砂等 6类新近沉积土的自振柱试验 ,详细探讨了围压大小、剪应变水平、土的颗粒组成和结构性对这 6类新近沉积土的剪切模量G及阻尼比λ的影响。通过与Seed和Idriss建议的砂土G/Gmax～γ和λ～γ曲线变化范围的对比 ,结果表明 ,不能将粉质粘土与粉砂互层土简单地当作砂土或粉质粘土对待。通过试验和理论分析 ,给出了南京及其邻近地区 6类新近沉积土动剪切模量和阻尼比随剪应变变化的平均曲线的拟合曲线、包络线及其参数的推荐值 ,对实际工程具有一定的借鉴作用

Experimental Study on Dynamic Shear Modulus and Damping Ratio of Recently Deposited Soils in Nanjing and Its Neighboring Areas

In the paper, by analyzing the results of free vibration column apparatus test on recently deposited soils of floodplain including clay,silty clay,mucky silty clay,Silty clay and fine sand interbedded strata,silt and fine sand in Nanjing and its neighboring areas. The effect of confining pressure, shear strain and soil structure property on dynamic shear modulus G and damping ratio λ was investigated in detail. Comparing with the variation range of G/Gmax～γ and λ～γ curves of sand recomas sandy soil or silty clay. Furthermore, based on the test results and theoretical analysis, the averaging curves, recommended values and envelopes of dynamic shear modulus ratio G/Gmax and damping ratio λversus dynamic strain γ for recently deposited soils in Nanjing and its neighboring areas are presented. However, the proposed values can only be used for reference for actual engineering projects.