How to Use a Micro Jacking

How to use micro pipe jacking

(1) Main jacking:

Use 4 200-ton jacks as the main jacks, and the jack stroke is 1.4 meters. The jack power is provided by an oil pump. The rear end of the jack uses a wooden block and a pressure ring to evenly apply the reaction force to the working well, and the front end pushes the pressure ring, and the jacking iron transmits the jacking force to the pipe section. The pressure ring is made with sufficient rigidity and is relatively flat in contact with the pipe end face, and does not deform.

(2) Relay room:

In the process of long-distance jacking, when the jacking resistance exceeds the allowable total jacking force and the jacking distance cannot be reached at one time, a relay room must be set up to relay the jacking in sections. When the jacking length of this pipe jacking project exceeds 100 meters, consider setting up a relay room behind the machine head and using thixotropic mud grouting technology.

The relay room consists of a front shell, a jack and a rear shell. The front housing connects to the front pipe, and the rear housing connects to the rear pipe. The front and rear housings are connected using a socket-and-spigot joint. A rubber waterstop seals the gap between them to prevent backflow of soil, water, and slurry from outside the pipe.

Each relay bay is equipped with ten jacks, each with a 30-ton jacking capacity, evenly spaced around the circumference. The jacks have a stroke of 28 cm and are secured to the front housing with flat iron fasteners. The steel housing structure is machined to prevent deformation during operation. The outer diameter of the relay bay housing is the same as the outer diameter of the pipe segment, minimizing soil disturbance, ground settlement, and jacking resistance.

Once the pipeline is jacked through, the jacks and various accessories are removed, and the gap between the outer housing and the inner wall of the pipe segment is filled with fine stone concrete.