Explosive forming of concrete post hole feet - core-ring drive charge produces given foot shape with correct soil compression

摘要

Explosive enlargement of the foot of a concrete pile which is to be anchored in the ground where an explosive charge dropped in the foot point of the pile hole and tamped by the fresh concrete introduced into the bore hole, is set off. The explosive charge is introduced as a directed core-ring drive charge to produce a given pile foot shape and to produce a given and directed compression of the soil surrounding the pile foot. An explosive with a higher detonation speed (up to 7000 m/sec) is used for the core drive charge than for the ring drive charge (up to 4000 m/sec).