The invention discloses an extremely soft phyllite tunnel surrounding rock parameter inversion method and
system, and relates to the technical field of
tunnel engineering. Comprising the following steps: acquiring basic mechanical parameters,
partial pressure parameters and damage parameters of a rock
mass; determining to-be-inverted parameters of the rock
mass and setting a value range, and performing
sensitivity analysis on the to-be-inverted parameters; carrying out a mixed horizontal orthogonal experiment on the to-be-inverted parameters based on a
sensitivity analysis result, and carrying out numerical
simulation on the rock
mass; constructing a prediction model by utilizing a
support vector machine (SVM), taking a numerical
simulation result as input, and training the model by adopting a random division
cross validation method; and predicting the optimal solution of the to-be-inverted parameters of the rock mass by using the trained prediction model. Based on
sensitivity analysis of a single to-be-inverted parameter of the HJC model, parameters which greatly influence response variables are identified, so that the proportion of the
key factors in a mixed level orthogonal experiment is increased by focusing on the
key factors, and the efficiency and accuracy of model training are greatly improved.