中文摘要：

为预估路基的永久变形,在万能材料试验机上对砂土进行了重复加载动三轴试验,得到了砂土永久变形的发展曲线,建立了塑性应变和荷载作用次数之间的关系式,使用最小二乘法拟合出该式中的系数与含水量和回弹模量之间的回归公式,并对回归公式进行了可靠性分析。当荷载作用次数为10000次时,现有路基土永久变形模型预估结果与试验结果相对误差最小为52%,最大高达376%;而系数与含水量和回弹模量之间的回归公式相关系数最小值为0.31,平均值为0.41,大于临界值0.28,试验曲线与理论曲线相关系数大于0.99。分析结果表明：建立的砂土永久变形预估公式可靠性较高,而现有预估模型不适用于砂土。

英文摘要：

In order to predict the permanent deformation of subgrade, a dynamic triaxial test of sandy soil under repeated load was made by using universal testing machine （UTM）, the development curves of the deformation were got, the relationship formula between plastic strain and load acting time was found, the regression formulas among the coefficients of the relationship formula, water content and resilient modulus were fitted by using least square method, and their reliability was analyzed. Analysis result shows that when load acting time reaches 10 000, the minimum and maximum relative errors between permanent deformation prediction result and measured result are 52 % and 376 % respectively; the minimum and average correlative coefficients of the regression formulas are 0. 31 and 0. 41 respectively, which are greater than the critical value of 0. 28, and the correlative coefficient between theoretical curve and measured one is more than 0. 99. So the reliability of the proposed prediction formulas of permanent deformation for sandy soil is higher, but existing prediction model is not suitable for sandy soil. 2 tabs, 4 figs, 16 refs.