Edogawa left bank basin sewer pipe construction work (Ichikawa trunk line 502-2 construction area)

Construction details High-density slurry type pipe jacking method with compatible type for underground obstruction
Method Milling mole method
Completion date Feb. 2015
Location of Construction Ichikawa city, Chiba Prefecture
Ordering party Chiba Prefecture Edogawa Sewerage Office
Pipe diameter φ1350㎜
Distance L=142.9m
Type of soil Sandy soil and cohesive soil
Gravel size

Work summary

Nominal diameter φ1350mm
Distance of pipe jacking L=142.021m (Curve with R150m)
Type of soil Sandy soil and cohesive soil
N value Average 18.5
Percentage of gravel -
Maximum gravel size -
Groundwater level GL-2.66m
Overburden 21.34m~20.92m
Underground obstacles Press-in caisson wall (Launching side L = 0.9m, reaching side L = 0.3m) (not detected this time, assumed SMW H-beam)
Construction period Daytime work (10h) Dec. 2014~Feb. 2015 (2.5 months)

During the construction of the lower stage (φ1350mm slurry type pipe jacking method, construction by another contractor), there was a hard soil obstacle & the bit was damaged, so the design was changed. In order to safely launch & reach, the press-in caisson wall (which was supposed to be unreinforced but actually contains a little rebar) was cut at L = 0.9m on the launching side & L = 0.3m on the reaching side.

Discharged concrete pieces

Discharged concrete pieces