In a piling construction management method a support strength of a hole bottom is measured with a penetration testing device before erecting a piling in a piling hole. The piling is erected in the piling hole when the measurement is at least a prescribed value. The penetration testing device has a knocking block with an integrated penetration shaft and the block is struck by a drive hammer in free-fall. The penetration testing device determines the support strength from the number of impacts required for the penetration shaft to penetrate to a prescribed depth from the hole bottom.