黄土高填方场地工后沉降预测新模型

New Prediction Model for Post-Construction Settlement of Loess High Fill Site

黄土高填方场地的工后沉降预测结果是确定地面工程建设时序和空间布局的重要依据.为准确预测黄土高填方场地的工后沉降量,在分析典型黄土高填方场地沉降数据特点、曲线特征和发展演化规律的基础上,提出了收敛型和发散型两种用于工后沉降预测的新模型;介绍了新模型的基本性质与参数求解方法,并检验了新模型在典型黄土高填方场地工后沉降预测中的应用效果.结果表明:新模型的内拟合误差和外推预测误差均较小,适合黄土高填方场地的工后沉降预测,其中发散型模型更适合“S”形沉降曲线的外推预测,平均绝对百分比误差(MAPE)为4.6%,相较于传统预测模型的外推预测误差降低了78.7%~95.8%;收敛型模型更适合“J”形沉降曲线的外推预测,平均绝对百分比误差(MAPE)为1.9%,相较于传统预测模型的外推预测误差降低了68.3%~84.4%;新模型具有较好的适应性、通用性和稳定性,可为今后黄土高填方场地的工后沉降预测和评估提供更多的选择和参考.

The post-construction settlement prediction of loess high fill site is an important basis for determining the time sequence of construction and the spatial layout of ground engineering. In order to accurately predict the post-construction settlement of loess high fill site, two post-construction settlement predictive models, one is a convergent model and the other is a divergent one, were proposed based on the characteristics of settlement data and the evolution laws of settlement curves of two typical loess high fill sites. The basic properties of the models,the solution to the parameters of the models, and the applicability of the proposed models in predicting the postconstruction settlement of typical loess high fill site were all presented in detail.The results show that the proposed models are suitable for post-construction settlement prediction of loess high fill site due to its smaller fitting error and prediction error. Moreover, it is found that the divergent model is more suitable to the grounds whose settlement curves have S-shape, the mean absolute percentage error(MAPE) is 4.6%, which is 78.7%-95.8% lower than the prediction error of the traditional prediction models, while the convergence model is more applicable to the grounds whose settlement curves have J-shape, the mean absolute percentage error(MAPE) is 1.9%, which is 68.3%-84.4% lower than the prediction error of the traditional prediction models.Due to their good adaptability, generality and stability, the proposed models can provide more choices and references for the prediction and evaluation of post-construction settlement of loess high fill site in the future.