云南粉土的动力特性试验研究

粉土是一种具有特殊工程性质的土,由粉土液化引起的工程震陷造成的危害极大。根据云南粉土的室内共振柱试验,得到了归一化处理后的G/Gm ax~γ/rγ和D~γ曲线,并运用修正后的双曲线模型进行了拟合分析。根据室内振动三轴试验,得出不同固结比和不同固结压力下的土的动强度与振动次数的试验曲线,发现动强度与破坏振次间符合较好的乘幂关系,动强度与固结比之间符合较好的二次抛物线关系;分析不同围压下孔压与破坏振次的试验曲线规律,发现可以用指数函数进行拟合。结果可供该类土的动力特性研究参考。

Laboratory Study on Dynamic Properties of Silty Soil

Much destruction would be caused by vibration in various natural disasters.The dynamic characteristic of sand,especially liquefaction characteristic,has been studied for a long time,while the history of the study of dynamic characteristic of silty soil is relatively short.Liquefaction is known to be caused by earthquake shaking,with the state of soil changing from solid to liquid.Silty soil is one of the engineering soils in nature of special interest,with distinct characteristics from those of sand.Earthquake-induced settlement caused by silty soil liquefaction is most dangerous.Based on sympathetic vibration tests of Yun-Nan silty soil,G/G_(max)～γ/γ_r curve and D～γ curve are obtained after being normalized,which then is analyzed and fitted by modifying hyperbola model.Based on dynamic triaxial tests,we obtain the relative curve between dynamic strength and vibration number of failure for different consolidation pressure,which accords with power hypotaxis preferably.We can also obtain the relative curve between dynamic strength and vibration number of failure for different consolidation ratio,which accords with hypo-twain parabola better.By analyzing the trial curve of pore pressure and vibration number of failure for different consolidation pressure,we assure that it can be fitted by exponential function.All these analysis can be used as a reference for computation and analysis.