The deformation characteristics of soil under lightning impulse were studied. The shock wave theory was used to describe the lightning impulse pressure

and the expression for the electromagnetic force generated by lightning in the soil was derived based on Maxwell′s equations. Using Drucker-Prager elastic-plastic criterion

the finite element model of dynamic deformation characteristics of soil under lightning impulse pressure and electromagnetic force was established. The transient computation was performed to investigate the deformation characteristics of soil during lightning strikes

and the dynamic analysis of the deformation was carried out by combining the stress distribution characteristics in the soil. With the orthogonal analysis method

the influence of soil mechanical parameters on the model results and the ranking of primary and secondary factors were studied

and the influence of critical factors and lightning current peak was analyzed. Results show that under the action of lightning impulse

the deformation of soil increased sharply at first

then slowed down gradually

and tended to be stable after partial springback. In this process

the stress distribution in the soil was similar to the stress wave propagation. The internal friction angle and elastic modulus within the soil had more significant effect on the deformation

and a smaller value could cause a significant increase in deformation. The change in internal friction angle also affected the distribution law of vertical deformation curve of surface soil. In addition

the influence of electromagnetic force on soil deformation increased significantly with the increase in the peak value of lightning current.