Ground surface settlement prediction method for construction of variable cross-section tunnel underneath passing existing structure

The embodiment of the invention discloses a variable cross-section tunnel underneath pass existing structure construction ground surface settlement prediction method, relates to the technical field of tunnel engineering, and can improve the prediction precision of the variable cross-section tunnel underneath pass existing structure construction ground surface settlement. The method comprises the following steps: determining a first section section and a second section section of a tunnel, and a transition section in transition connection with the first section section and the second section section; according to initial parameters of the excavation faces of the first section section and the second section section during tunnel construction and convergence parameters after tunnel construction, initial parameters and convergence parameters of the excavation faces of the transition section are determined; based on the excavation face initial parameters and convergence parameters of the first section section, the