Lightning-induced fracture of masonry and rock

As a lightning channel on its way to ground meets a standing masonry or rock structure, radiant energy from the channel can induce a thermal shock of sufficient intensity to cause the structure to fracture and collapse. Mathematical models for two such structural failure mechanisms are proposed: one describing violent surface separations or spalling, and the other characterizing internal cracking from sudden increased pore pressure in the solid. Experimental data and case studies are used to complement these theories of lightning-induced failure.