Saitama Eastern Line (Phase 4) Water pipe renewal work

Construction details High-density slurry type pipe jacking method with compatible type for underground obstruction
Method Milling mole method
Completion date Dec. 2015
Location of Construction Saitama city, Saitama Prefecture
Ordering party Saitama Prefectural Waterworks Maintenance Office
Pipe diameter φ800㎜
Distance L=116.9m
Type of soil Silt mixed with sand
Gravel size

Work summary

Nominal diameter φ800mm
Distance of pipe jacking 116.876m
Type of soil Silt mixed with sand
N value 0
Percentage of gravel -
Maximum gravel size -
Groundwater level GL-1.5m
Overburden 7.37~5.33m
Underground obstacles Steel sheet pile(type Ⅲ) 1 place, PC pile (Φ200mm) 1 place
Construction period (Day and night work 8.0h) Oct. 2015~Dec. 2015 (2 months)

Initially, it was constructed by the High-density slurry type pipe jacking method, but after 30 m from driving shaft, an obstacle was encountered.
After that, a survey and trial trench were conducted, and it was found that there was a leftover shaft.
It was also found that there is a box culvert foundation PC pile at 70m from the driving shaft.
After discussions with the authority, it was decided to extract the PC piles and restart with the milling mall method.
It took time to cut, but TBM was able to reach safely.

Discharged metal pieces

Discharged metal pieces