膨胀土粒径分布测量方法的试验研究及曲线拟合

Experimental Study of Expansive Soil Particle Size and Distribution Measurement Curve Fitting Method

土体的粒度成分在土体的定名、鉴别、描述及预测土体工程性质上具有重要应用。为了研究非饱和土体粒度成分的测量方法及测量结果,本文分别采用密度计法、移液管法和激光粒度仪法对合肥地区9种非饱和膨胀土进行了粒度测量,得到了相应的粒径分布,并采用Fredlund模型进行了曲线拟合,得到了试验土体的粒径分布曲线(PSD),求得了相应的曲线拟合参数的均值、均方差及变异系数。在此基础上,对3种测量方法的PSD曲线拟合参数进行了回归分析,求得了激光法的PSD拟合参数与传统的密度计法及移液管法的PSD拟合参数间的相关关系。

Granulometric composition of soil has important applications in the naming,identification,description and prediction of soil engineering properties.In order to study measurement of unsaturated soil composition,density meter method,pipette method and laser particle size analyzer method were employed.Particle size of nine kinds of unsaturated expansive soil in Hefei were measured and corresponding grain size distribution were obtained.By using a curve fitting model Fredlund,particle size distribution curve of the test soil（PSD）was obtained,as well as the mean value,variance and variation coefficient of the corresponding curve fitting parameters.On this basis,regression analysis was conducted on the PSD curve fitting parameter obtained by the three methods and relationship was examined between the fitting parameter of PSD laser densitometer and those of the traditional densimeter method or pipette method.