Verhulst模型在预测软基路堤沉降中的应用

APPLICATION OF VERHULST MODEL TO PREDICTION OF ROADBED SETTLEMENT ON SOFT SOIL

通过分析软基路堤沉降和Verhulst模型的特征发现,软基路堤沉降随时间的变化曲线与Verhulst模型曲线相似。根据泉州安吉路软基试验段路堤沉降观测值,采用Verhulst模型对其进行沉降预测,尽管施工期的预测值与实测值有一定差距,但随着时间的增长,二者逐步接近,因此该模型可用于最终沉降的预测。Verhulst模型能有效削弱原始数据中不规则数据随机性的影响,具有很强的适应性。同时,还对预测值与实测值的差异、观测历时对预测值的影响以及最终沉降量的推算等问题进行探讨。高压缩性软基上的路堤,至少需要4～6个月填土放置期的观测数据,才能得到较准确的最终沉降预测值。路堤最终沉降可以通过考虑预测值与实测值的差异以及观测历时的影响这两个系数,对预测值进行修正,所归纳的系数对类似工程有一定参考价值。

After analyzing the characters of roadbed settlement and Verhulst model,it is found that the observed curve of roadbed settlement with time is quite similar with that calculated from Verhulst model.The prediction of settlement of Anji roadbed on soil base in Quanzhou City by using Verhulst model gradually approaches to the observed values although there are some differences between predicted values and observed ones during construction period.Therefore,Verhulst model can be used to predict the ultimate settlement.This model has good adaptability because the influence of randomicity of irregular original data can be weakened efficiently.The difference between predicted values and observed ones,the influence of observation period on predicted values and the calculation of ultimate settlement are also discussed.The more precise predicted values of ultimate settlement need values observed for at least four to six months for soft roadbed.The ultimate settlement predicted by observed values can be modified by two coefficients,i.e.the ratio between observed values and predicted ones and the influence coefficient of observation period.These two coefficients can be also used in the similar projects.