Abstract Because the surface settlements are different in different stages of an excavation cycle by an EPB shield, and some defects exist in the current prediction methods, this paper discusses the dynamic prediction method for longitudinal surface settlement using the nearest neighbor bootstrap regressive model (NNBR model). Soil pressure and average driving speed, grouting pressure and average driving speed, and monitoring time are considered to be the main predictiors of surface settlement in front of the excavation face, gap settlement at the shield tail, and consolidation settlement. Similarly, calculation formulas for corresponding stages are presented. The consolidation settlement in one case was predicted by the above method, with the maximum relative error of 14.04%, which demonstrates the accuracy and feasibility of the dynamic prediction method based on NNBR model.
Abstract：
Because the surface settlements are different in different stages of an excavation cycle by an EPB shield, and some defects exist in the current prediction methods, this paper discusses the dynamic prediction method for longitudinal surface settlement using the nearest neighbor bootstrap regressive model (NNBR model). Soil pressure and average driving speed, grouting pressure and average driving speed, and monitoring time are considered to be the main predictiors of surface settlement in front of the excavation face, gap settlement at the shield tail, and consolidation settlement. Similarly, calculation formulas for corresponding stages are presented. The consolidation settlement in one case was predicted by the above method, with the maximum relative error of 14.04%, which demonstrates the accuracy and feasibility of the dynamic prediction method based on NNBR model.
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published: 2012-03-20
Cite this article:
WANG Hong-Wei
.Dynamic Prediction of Longitudinal Surface Settlement based on the NNBR Model[J] MODERN TUNNELLING TECHNOLOGY, 2012,V49(6): 82-87
2012, Vol. 49 