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Global Sensitivity Analysis on Parameters of the Prediction Model for Shield Vertical Attitude
(1 School of Civil Engineering, Xi'an University of Architecture and Technology, Xi′an 710055; 2 Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi′an 710055)
Abstract The shield attitude deviation from the designed axis is a common construction problem. Determining sen? sitive factors that may influence the shield attitude is of great significance for the shield attitude control. To quantitatively analyze the sensitive factors that may influence the shield vertical attitude, a shield construction case in pebble ground with underlying expansive mudstone stratum in Chengdu is taken as the engineering background, and the support vector regression (SVR) algorithm is used for establishing a prediction model for the shield vertical attitude,with the tunnelling parameters, geological parameters, and geometric parameters as input variables, and the shield vertical attitude tendency as the output variable. On this basis, the Sobol′ sensitivity analysis method is used for quantitative analysis on the global sensitivity of the model parameters. The research results show that the model prediction results are in good agreement with the actual results, which proves the reliability of the SVR model in the shield attitude prediction; It is concluded that the thrust difference between the upper and lower jacks is the most sensitive factor, the first-order sensitivity of synchronous grouting is relatively higher, and the first-order sensitivity,coupling sensitivity, and total-order sensitivity of geological parameters and the geometric parameters are all higher.
Abstract：
The shield attitude deviation from the designed axis is a common construction problem. Determining sen? sitive factors that may influence the shield attitude is of great significance for the shield attitude control. To quantitatively analyze the sensitive factors that may influence the shield vertical attitude, a shield construction case in pebble ground with underlying expansive mudstone stratum in Chengdu is taken as the engineering background, and the support vector regression (SVR) algorithm is used for establishing a prediction model for the shield vertical attitude,with the tunnelling parameters, geological parameters, and geometric parameters as input variables, and the shield vertical attitude tendency as the output variable. On this basis, the Sobol′ sensitivity analysis method is used for quantitative analysis on the global sensitivity of the model parameters. The research results show that the model prediction results are in good agreement with the actual results, which proves the reliability of the SVR model in the shield attitude prediction; It is concluded that the thrust difference between the upper and lower jacks is the most sensitive factor, the first-order sensitivity of synchronous grouting is relatively higher, and the first-order sensitivity,coupling sensitivity, and total-order sensitivity of geological parameters and the geometric parameters are all higher.
HU Changming1,
2 LI Liang1 MEI Yuan1,
2 YUAN Yili1 WANG Zhiyu1
.Global Sensitivity Analysis on Parameters of the Prediction Model for Shield Vertical Attitude[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(2): 127-134
2021, Vol. 58 