Pipejacking in Wet Sandy Clay
Diona excavated the 4.5m deep launch shaft so the jacking frame could be inserted in advance of the shutdown weekend. As the launch shaft was 38m from the Railcorp property line this distance was able to be pipejacked prior to the weekend shutdown. This left 58m of Ø1020mm microtunnel to be pipejacked during the shutdown.
2 crews of 5 men worked consecutive 12 hour shifts commencing 3am Saturday morning. The first shift jacked 11 pipes or 26m, the second shift (Saturday Night) commencing at 3pm on Saturday afternoon jacked 10 pipes or 24m.
Breakthrough – Third Shift Sunday, day.
The day shift had 3 pipes to jack on their shift and they broke through at 8am leaving the remainder of the shift to remove the microtunnelling head from the exit shaft, retract the 39 rods and grout the annular space between the jacking pipes and the microtunnel.
The jacking frame and the remainder of the equipment were removed from site over the next couple of days. Diona then welded and inserted the steel main and completed pipework including the connections to the existing reticulation system.
The surveyor observed ‘zero’ settlement of the rails.
The drill rods and vacuum tube are installed inside the 800 diameter J-Series RCJP ready for lowering into the shaft.
Another pipe and rod assembly is lowered into the shaft.
The RCJP is lowered into the shaft.
Once lowered services are threaded through the new pipe. All services are reconnected, the pipes are joined and microtunnelling recommences.
Early morning Microtunnelling.