Calculation of Radii of the Broken and Cracked Areas in Rock by a Long Charge Explosion

The formulae are deduced for calculation of the radii of the smashed and cracked areas in rock by a long charge explosion, with the Mises' strength criterion. Meanwhile, the three-directional load and strain-rate effects of rock are taken into consideration. Then, the explosive charge for the controlled perimeter blasting is discussed. For the familiar rocks, the values from the formulae accord with blasting practice.