A Semi-Analytical Solution for Shock Wave Pressure and Radius of Soil Plastic Zone Induced by Lightning Strikes

A semi-analytical solution for forecasting the soil behavior induced by lightning strikes is of great engineering significance to calculate the radius of the soil plastic zone. In this paper, a simplified two-stage method is employed to solve the shock wave pressure and the radius of the soil plastic zone. The solution is verified against experimental data. Using the present model, the major factors dominating the shock wave pressure and the radius of the soil plastic zone are investigated. The results show that (1) the radius of the soil plastic zone (r(p)) induced by lightning decreases monotonically with cohesion (c) and internal friction angle (phi), while c has a better effect on soil properties than phi does; (2) increasing the initial radius of the plasma channel (r(i)(0)) can reduce the pressure (P) and increasing r(i)(0) has a nonnegligible effect on r(p); with r(i)(0) increasing by 100%, the radius of the soil plastic zone increases by 47.9-59.7%; (3) the plasma channel length (L) has a significant influence on P and r(p), especially when L is at a relatively low level; (4) the r(p) induced by lightning decreases exponentially with attenuation coefficient (a); (5) the wavefront time is a major factor while the half-value time is a minor factor for the shock wave pressure induced by plasma explosives.