When the jack operation is suspended, the buttress must be used to replace the force. The jack is used as insurance, and the jack must not be subjected to force for a long time.
When the jack operation is suspended, the support must be replaced with a support, the jack is insured, and the jack can never be forced for a long time.
When the jack operation is suspended, the supporting pier must be used to replace the stress, and the jack shall be used as the insurance. The jack must not be stressed for a long time.