(1) The foundation of the jack. The foundation of the jack shall be stable, solid and reliable. When the jack is set on the bottom surface, it shall be padded with track wood or other appropriate materials to expand the stress area.

(2) Jack placement. When the jack is placed on the soft ground, a wooden block shall be placed under the jack to avoid tilting and tilting after being stressed. When the weight rises, the supporting skid shall be placed under the weight at any time, but the hand shall not enter the danger area by mistake.

During the placement of the jack, keep the action line of the load center of gravity consistent with the axis of the jack. During the lifting process, it is necessary to strictly prevent the danger of the jack deflection and tilt due to the eccentric settlement of the jack foundation or the horizontal displacement of the load. To prevent the jack from sliding in contact with the metal surface of the heavy object or the smooth surface of the concrete, hardwood blocks shall be padded when necessary.

(3) Jacking operation. The lifting height of the jack shall not exceed the effective jacking distance. When lifting large objects (such as girders), both ends shall be lifted and lowered separately, one end shall be lifted and lowered, and the other end must be firmly padded and placed. The jack shall not be overloaded.

The jack should not be started quickly, but should rise at a constant pace and fall slowly. When multiple jacks are used at the same time, they shall be operated synchronously. After the operation of the jack, it is necessary to carefully check the oil pressure and hidden danger, and carry out maintenance, and place it in an appropriate place.