The invention relates to the technical field of frozen soil deformation prediction, and particularly discloses a thermal-mechanical
coupling frozen soil deformation rapid prediction method based on a
material point method, and the method comprises the steps: building an improved Takashi three-dimensional
frost heaving model; thermal-mechanical
coupling frozen soil deformation calculation: carrying out initialized background grid boundary division on the predicted frozen soil position; calculating the
temperature gradient according to the node temperature, calculating the
heat flux density of the material point, and updating the node temperature and the temperature of the material point; judging whether the material point reaches a
frost heaving condition or not according to the updated material point temperature, and if the material point reaches the
frost heaving condition, performing
frost heaving strain calculation; calculating the
strain rate and the rotation rate of the substance point, updating the volume of the substance point by using the
strain rate of the substance point, and updating the stress of the substance point by using the constitutive relation; calculating node force and updating node
momentum, applying displacement boundary conditions again, mapping node acceleration and velocity back to the material point, and updating the velocity and position of the material point; and repeating the calculation of the next
time step by using the undeformed grid.