曲线拟合法对路基小变形情形适用性研究

双曲线法、三点法、指数曲线法和Asaoka法等曲线拟合法在软土路基的沉降预测中已经得到广泛应用，但在路基小变形情形的应用研究尚少。结合某铁路客运专线施工现场观测的路基小变形数据，对这4种方法，探讨了时间起点和样本值的起止时间间隔对相关系数的影响，且验算后期观测值的预测效果；并综合考虑了相关系数和相对误差，研究每种方法的适用性；指出了4种拟合方法在路基小变形情形应用的优缺点。研究表明：数据的波动会造成指数曲线法无法计算；沉降数据波动较小时，双曲线法、三点法、Asaoka法的拟合效果均较好；当沉降数据波动较大时，仅三点法、Asaoka法的拟合效果较好，双曲线法较差。

Study of applicability of curve fitting methods in small settlement of subgrade

Hyperbola method, three-point method, exponent curve method, Asaoka method etc. are widely applied to settlement prediction for soft soil ground; but less study of applying to case of small settlement. With regard to the four methods, the small settlement data from the construction site of a passenger dedicated railway line are used to study the influence of starting point of calculation time and span of starting and ending time of the sample on relative error and prediction effect of the last observed values are checked. Comprehensively considering correlative coefficient and relative error, the applicability of every method is studied and the advantages and disadvantages for every method are analyzed. The research results show that the exponent curve method can not fit to the case of small settlement: other three methods all provide better fit to the real data when the settlement data fluctuation is small; however only three-point method and Asaoka method fit better if settlement data fluctuation is not small.