Various techniques used to limit the amount of [[Backbreak|backbreak]] developed during the blasting phase of the excavation cycle by reducing the level of ground shock vibrations, and by terminating cracks due to expanding explosive gases by defining a perimeter limit such as a preshear line. [[Cushion Blasting|Cushion blasting]], [[Buffer Blasting|buffer blasting]], preshear and postshear are some of the methods used, in addition to the old standby methods of reducing charge weight/delay and blast timing to reduce destructive vibrations from opening shear zones and faults, as well as bedding planes, etc.