The invention discloses a small-clear-distance tunnel backward shield excavation face
support pressure determining method which comprises the steps that
soil parameters are collected, data comprise soil cohesion and
internal friction angle data, geometric parameters of tunnel
diameter, burial depth and clear distance are recorded, numerical model construction is conducted through the collected parameters,
numerical models of a tunnel and surrounding soil are constructed, and the tunnel backward shield excavation face
support pressure is determined. Meanwhile, analyzing the stress state, stratum type and address characteristic data of the soil body by utilizing a numerical model, simulating an excavation process after
data analysis is completed, simulating a propelling process of a
shield tunneling machine, gradually removing the soil body, applying corresponding
support pressure, and recording the support pressure, soil body deformation and displacement data at different time points; the method is based on numerical
simulation and
machine learning methods, the multi-factor
coupling influence is systematically considered,
blindness of an experience method is avoided, the established relational expression covers a wide parameter change range, and the method can be suitable for small-clear-distance projects with different geological conditions and tunnel design parameters.