准等时距QGM(1,1)模型分段预测法及其在草炭土路基沉降预测中的应用  

Quasi-Equal Interval QGM(1,1) Model Forecasting Method and Its Application in Settlement Prediction of Turfy Soil Subgrade

作　　者：沈世伟[1] 佴磊[1] 徐燕[1] 

机构地区：[1]吉林大学建设工程学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2011年第4期1098-1103,共6页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(40772169)

摘　　要：利用传统非等时距模型预测草炭土路基沉降时,存在计算繁琐、中短期预报精度低等缺点,尤其是当沉降曲线存在斜率突变点时,采用该模型很难达到预测精度的要求。针对以上不足,对非等时距时间序列进行平均步长换算,得到准等时距序列,利用线性插值法对原始沉降数据进行修正,得到改进后的准等时距QGM(1,1)预测模型,并将沉降曲线在斜率突变点处分成两部分进行分段预测。实例计算表明:采用改进后的准等时距QGM(1,1)模型预测草炭土路基沉降,两段的预测值平均误差分别为2.99%和0.25%,均远远小于传统非等时距模型,且具有很高的中短期预测精度,可以为工程沉降控制提供可靠参考。To predict the settlement of turfy soil subgrade with the method of traditional non-equal interval models,there are a few shortages such as cumbersome calculation and low accuracy for short-term forecast Especially when there is a slope mutation point in the subsidence curve,it is difficult to meet the prediction accuracy requirements.For the above shortcomings,average step length conversion is used for non-equal interval sequence to obtain quasi-equal interval sequence;the improved quasi-equal interval QGM（1,1） forecasting models are obtained by amending the original settlement data with the method of linear interpolation;and the subsidence curve is divided into two parts to carry out the prediction at the slope mutation point.As is illustrated in the examples,when the improved quasi-equal interval QGM（1,1） models are used to predict turfy soil subgrade settlement,the average errors between predicted and measured values are 2.99% and 0.25% respectively,far less than the results obtained by means of traditional non-equal interval models.The quasi-equal interval QGM（1,1） model with pretty high accuracy for short-term prediction can serve as a reliable reference to settlement control in project.

关 键 词：准等时距QGM(1 1)模型 平均步长换算 分段预测 草炭土 沉降预测 

分 类 号：TU433[建筑科学—岩土工程]