Objective Addressing the typical soft and hard composite stratum conditions in Guangdong-Hong Kong-Macao Greater Bay Area, a modified calculation model for micro-disturbance in metro engineering suitable for complex strata is proposed to reduce construction risks caused by soil disturbance.

Method By establishing the calculation coordinate system for the shield tunnel, the influence range α and the empirical coefficient k are introduced to modify the Wei Gang's model. Taking several typical interval projects of Guangzhou Metro as examples, data from 35 measuring points in the typical intervals are selected. By calculating the disturbance conditions of the measuring points and combining them with numerical simulation results, the accuracy and applicability of the proposed modified model are analyzed. An exponential function model is adopted to fit the α and k values of the measuring points to verify the prediction accuracy of the proposed modified model.

Result & Conclusion  The maximum absolute error of vertical soil displacement for the proposed modified model is 1.18 mm, whereas the maximum absolute error of vertical soil displacement for the Wei Gang's model is 10.10 mm, indicating that the proposed modified model possesses high prediction accuracy. The fitting model achieves a determination coefficient of 0.968, demonstrating that the modified model has a good fitting effect and can accurately reflect the variation trend of the actual data. Through comparison with the numerical simulation results, the reliability and applicability of the proposed modified model under complex geological conditions are verified, providing a new technical method for the high-precision prediction of stratum disturbance during metro tunnel construction and holding high engineering application value.